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Posted to dev@ignite.apache.org by Ivan Pavlukhin <vo...@gmail.com> on 2021/08/02 08:17:58 UTC
Re: Text Queries Support
Folks,
Sorry if read the thread not thoroughly enough, but do we consider
Lucene as obviously right choice? In my understanding Ignite history
has shown clearly that "fastest feature implementation" is not usually
the best. And one example of this are text queries. Are not we trying
to do a same mistake again? FTS is a huge feature, I do not believe
there is an easy win for it.
2021-07-27 19:18 GMT+03:00, Atri Sharma <at...@apache.org>:
> Andrey,
>
>> Per-partition Lucene index looks simple to implement, but it may require
>> per-partition SQL to make full-text search expressions work correctly
>> within the SQL quiery.
> I think that as long as we follow the map - reduce process that we
> already do for other queries, we should be fine.
>
>> Per-partition SQL index may kill the performance. We already tried to do
>> that in Ignite 2. However, QueryParallelism feature helps to speed up
>> some
>> data-intensive queries,
>> but hits the performance in simple cases, and at some point (e.g.
>> segments
>> > number of CPU) the performance rapidly degrades with the increasing
>> number of segments.
>
> Yeah, that is always the case, but a global index will be a nightmare
> in terms of concurrency and pessimistic concurrency control will
> anyways kill the benefits, coupled with the metadata requirements.
> What were the specific issues with per partition index?
>>
>> AFAIK, Lucene widely used bitmap indices that are easy to merge.
>> Maybe, the map-reduce technique underneath FTS expressions and some hacks
>> will add a minimal overhead.
>
> Lucene uses many types of indices but the aspect here is that per
> partition Lucene indices can return docIDs and we can merge them in
> reduce phase. So we are abstracted out from specifics of the internal
> index being used to serve the query.
>
>>
>> > As illustrated by Ilya, we can use Ignite's WAL records to rebuild
>> > Lucene indices. The important thing here is to not treat Lucene
>> > indices as source of truth.
>> To use WAL we either should relay Lucene files to our Page memory or be
>> aware of Lucene files structure.
>> The first looks tricky, as we should guarantee a contiguous address space
>> in Page memory for reflecting Lucene file. Maybe separate managed memory
>> segment with its own rules?
>
> Why not use Lucene's MMappedDirectory and map it to our storage classes?
>
>>
>> >> Transactions.
>> >> * Will we support transactions?
>> > Lucene has no concept of transactions.
>> Yes, but we have.
>> Lucene index may be non-transactional, but users never expect to see
>> uncommited data.
>> How does this connect with transactional SQL?
> We could have the Lucene writes done as a part of transactions and ack
> back only when it succeeds/fails. WDYT?
>>
>> On Tue, Jul 27, 2021 at 1:36 PM Atri Sharma <at...@apache.org> wrote:
>>
>> > Sorry, I planned on creating a Wiki page for this, but it makes more
>> > sense to be replying here.
>> >
>> > > * How Lucene index can be split among the nodes?
>> >
>> > We can have partition level indices on each node.
>> >
>> > > * If we'll have a single index for all partitions on the particular
>> > > node,
>> > > then how index records will be aware of partitioning?
>> >
>> > Index records dont need to be aware of partitioning -- each Lucene
>> > index is independent.
>> >
>> > > This is important to filter out backup records from the results to
>> > > avoid
>> > > duplicates.
>> >
>> > We can merge documents from different nodes and remove duplicates as
>> > long as docIDs are globally unique.
>> >
>> > > * How results from several nodes can be merged on the Reduce stage?
>> >
>> > As long as documents have a globally unique docID, Lucene has merge
>> > functions that can merge results from multiple partial results.
>> >
>> > > * Does Lucene supports smth like JOIN operation or others that may
>> > require
>> > > data from another partition or index?
>> >
>> > As illustrated by Ilya, Block-Join works for us.
>> >
>> > > If so, then it likes to multistep query with merging results on
>> > > intermediate stages and requires detailed investigation and design.
>> > > It is ok if Ignite will have some limitations here, but we would like
>> > > to
>> > > know about them at the early stage.
>> >
>> > > * How effectively map Lucene files to the page memory? Is it even
>> > possible?
>> >
>> > Lucene has PageDirectory implementations which allow storing Lucene
>> > indices on different kind of file structures. It has a
>> > MMappedFileDirectory that we could use?
>> >
>> > > Otherwise, how to deal with potential OOM on large queries and memory
>> > > capacity planning?
>> >
>> > We can use Lucene's MMapped directory.
>> >
>> > >
>> > > Persistence.
>> > > * How and what consistency guarantees could we have/expect?
>> >
>> > Lucene does not have WAL logs but is append only
>> >
>> > > Seems, we may not be able to write physical records for Lucene index
>> > > to
>> > our
>> > > WAL. What can we do with this?
>> >
>> > As illustrated by Ilya, we can use Ignite's WAL records to rebuild
>> > Lucene indices. The important thing here is to not treat Lucene
>> > indices as source of truth.
>> > >
>> > > Transactions.
>> > > * Will we support transactions?
>> > Lucene has no concept of transactions.
>> >
>> > > * Should Lucene be aware of Transaction and track mvcc (or whatever)
>> > > versions for the records?
>> > No
>> > > * What will be consistency guarantees?
>> > We can acknowledge writes back only after Lucene index is updated.
>> > >
>> > > UX
>> > > * How to add FullText search queries syntax into Calcite?
>> > Postgres's FTS functions are a good reference.
>> > > * AFAIK, the Lucene index has many properties for tuning. How will
>> > > the
>> > user
>> > > configure the index?
>> > Most of those properties can be cluster level and exposed as a new sub
>> > config for ignite.
>> > > * How and where to store the settings? What are cluster-wide and what
>> > > a
>> > > local to the particular node?
>> > All can be cluster level.
>> > > * Will be all the settings immutable? Can be they changed on-fly?
>> > > after
>> > > node/grid restart?
>> > They should be applied post restart.
>> >
>> > > * Any limitations on query syntax?
>> > It depends on how we model our queries for text search.
>> >
>> > >
>> > > SQL
>> > > * Will we support FullText search in SQL?
>> > We need custom functions for it. See Postgres's FTS functions.
>> > > * How to integrate Lucene index into Calcite? What is the cost model?
>> > There cannot be any cost model since there are no paths for a text
>> > query. If we see a text query, we have to use Lucene index or return
>> > an error. In this way, we need to model text search as a set of UDFs
>> >
>> > > Splitting rules? Traits?
>> > Please see my reply above.
>> > >
>> > >
>> > > With all of this, you can go with the IEP (or even some short
>> > > summary)
>> > and
>> > > further POC and implementation.
>> > > That's a big deal, so let's discuss what could be done here.
>> > >
>> > > On Fri, Jul 23, 2021 at 12:58 PM Atri Sharma <at...@apache.org> wrote:
>> > >
>> > > > I am actually happy to drive the feature for Ignite 3. FTS is very
>> > > > important for me and I think Ignite users will benefit from it
>> > > > greatly.
>> > > >
>> > > > If it makes sense to be focusing on Ignite 3 for this capability, I
>> > > > am
>> > > > eager to contribute there and lead the development.
>> > > >
>> > > > Please share your thoughts.
>> > > >
>> > > > On Fri, Jul 23, 2021 at 3:21 PM Andrey Mashenkov
>> > > > <an...@gmail.com> wrote:
>> > > > >
>> > > > > Hi Atri,
>> > > > >
>> > > > > All the Jira tickets we have on the Full-text search (FTS) thing
>> > > > > are
>> > > > > targeted to Ignite 2.
>> > > > >
>> > > > > AFAIK, we want, but we have NOT committed to FTS support in Ignite
>> > > > > 3,
>> > > > yet.
>> > > > > By the way, we are getting requests for this thing from the user
>> > side,
>> > > > and
>> > > > > definitely,
>> > > > > FTS would be a valuable feature for Ignite.
>> > > > >
>> > > > > It will be great if the one wants to drive it, any help will be
>> > > > appreciated.
>> > > > >
>> > > > >
>> > > > > On Fri, Jul 23, 2021 at 12:12 PM Atri Sharma <at...@apache.org>
>> > wrote:
>> > > > >
>> > > > > > Hello,
>> > > > > >
>> > > > > > An update, please. I am working through persistence of Lucene
>> > > > > > index
>> > > > using
>> > > > > > Ignite Dictionary, and will be asking some questions soon.
>> > > > > >
>> > > > > > I had one doubt - - where does this change go? Ignite 3?
>> > > > > >
>> > > > > > Also, I know we want to build native support for text searches
>> > > > > > in
>> > > > Ignite 3.
>> > > > > > Is the work I am proposing here part of that, or will that be a
>> > > > separate
>> > > > > > effort?
>> > > > > >
>> > > > > > On Mon, 28 Jun 2021, 19:20 Ilya Kasnacheev, <
>> > ilya.kasnacheev@gmail.com
>> > > > >
>> > > > > > wrote:
>> > > > > >
>> > > > > > > Hello!
>> > > > > > >
>> > > > > > > I think that number one is the most important one, then maybe
>> > > > > > > it
>> > > > will see
>> > > > > > > more use and other deficiencies become more apparent, leading
>> > > > > > > to
>> > more
>> > > > > > > tickets and visibility.
>> > > > > > >
>> > > > > > > Maybe 2. and 3. will even use a different approach when
>> > persistence
>> > > > is
>> > > > > > > implemented.
>> > > > > > >
>> > > > > > > Regards,
>> > > > > > > --
>> > > > > > > Ilya Kasnacheev
>> > > > > > >
>> > > > > > >
>> > > > > > > пн, 28 июн. 2021 г. в 14:34, Atri Sharma <at...@apache.org>:
>> > > > > > >
>> > > > > > > > Hello Again!
>> > > > > > > >
>> > > > > > > > I have been looking into the aforementioned and here are my
>> > follow
>> > > > up
>> > > > > > > > thoughts:
>> > > > > > > >
>> > > > > > > > 1. Support persistence of Lucene indexes.
>> > > > > > > > 2. https://issues.apache.org/jira/browse/IGNITE-12401
>> > > > > > > > (Needs
>> > > > fixing of
>> > > > > > > > moving partitions first)
>> > > > > > > > 3. Figure out how to return scores from nodes and use them
>> > > > > > > > as
>> > sort
>> > > > > > > > parameters on the coordinator node
>> > > > > > > > (https://issues.apache.org/jira/browse/IGNITE-12291)
>> > > > > > > >
>> > > > > > > > Please let me know if this looks ok to make text queries
>> > > > functional?
>> > > > > > > >
>> > > > > > > > Atri
>> > > > > > > >
>> > > > > > > > On Mon, Jun 21, 2021 at 2:49 PM Alexei Scherbakov
>> > > > > > > > <al...@gmail.com> wrote:
>> > > > > > > > >
>> > > > > > > > > Hi.
>> > > > > > > > >
>> > > > > > > > > One of the biggest issues with text queries is a lack of
>> > support
>> > > > for
>> > > > > > > > lucene
>> > > > > > > > > indices persistence, which makes this functionality
>> > > > > > > > > useless
>> > if a
>> > > > > > > > > persistence is enabled.
>> > > > > > > > >
>> > > > > > > > > I would first take care of it.
>> > > > > > > > >
>> > > > > > > > > пн, 21 июн. 2021 г. в 12:16, Maksim Timonin <
>> > > > timonin.maxim@gmail.com
>> > > > > > >:
>> > > > > > > > >
>> > > > > > > > > > Hi, Atri!
>> > > > > > > > > >
>> > > > > > > > > > You're right, Actually there is a lack of support for
>> > > > TextQueries.
>> > > > > > > For
>> > > > > > > > the
>> > > > > > > > > > last ticket I'm doing I see some obvious issues with
>> > > > > > > > > > them
>> > (no
>> > > > page
>> > > > > > > size
>> > > > > > > > > > support, for example). I'm glad that somebody wants to
>> > maintain
>> > > > > > this
>> > > > > > > > > > functionality. Thanks a lot!
>> > > > > > > > > >
>> > > > > > > > > > For the MergeSort algorithm there is already a patch
>> > > > > > > > > > for
>> > that
>> > > > [1].
>> > > > > > > It's
>> > > > > > > > > > currently on review. This patch introduces an abstract
>> > reducer
>> > > > for
>> > > > > > > > > > CacheQueries with 2 implementations (unordered,
>> > merge-sort).
>> > > > Then
>> > > > > > > > TextQuery
>> > > > > > > > > > leverages on MergeSort to order results from multiple
>> > nodes by
>> > > > > > score.
>> > > > > > > > This
>> > > > > > > > > > patch also fixes the pageSize issue, I've mentioned
>> > > > > > > > > > before.
>> > > > Could
>> > > > > > you
>> > > > > > > > > > please check if it fully matches your idea? Any issues
>> > > > > > > > > > or
>> > > > comments
>> > > > > > > are
>> > > > > > > > > > welcome.
>> > > > > > > > > >
>> > > > > > > > > > I've prepared this ticket, because I need the MergeSort
>> > > > algorithm
>> > > > > > for
>> > > > > > > > the
>> > > > > > > > > > new type of queries I'm implementing (IndexQuery, it
>> > > > > > > > > > should
>> > > > also
>> > > > > > > > provide
>> > > > > > > > > > ordered results over multiple nodes). Currently I'm not
>> > > > planning to
>> > > > > > > go
>> > > > > > > > > > further with TextQuery, so if you're going to support
>> > > > > > > > > > this
>> > > > it'll
>> > > > > > be a
>> > > > > > > > great
>> > > > > > > > > > contribution, I think.
>> > > > > > > > > >
>> > > > > > > > > > [1] https://issues.apache.org/jira/browse/IGNITE-14703
>> > > > > > > > > > [2] https://github.com/apache/ignite/pull/9081
>> > > > > > > > > >
>> > > > > > > > > >
>> > > > > > > > > > On Mon, Jun 21, 2021 at 11:11 AM Atri Sharma <
>> > atri@apache.org>
>> > > > > > > wrote:
>> > > > > > > > > >
>> > > > > > > > > > > Hi All,
>> > > > > > > > > > >
>> > > > > > > > > > > I have been looking into our text queries support and
>> > > > > > > > > > > see
>> > > > that it
>> > > > > > > has
>> > > > > > > > > > > limited community support.
>> > > > > > > > > > >
>> > > > > > > > > > > Therefore, I volunteer to be the maintainer of the
>> > module and
>> > > > > > work
>> > > > > > > on
>> > > > > > > > > > > enhancing it further.
>> > > > > > > > > > >
>> > > > > > > > > > > First goal would be to move to Lucene 8.x, then work
>> > > > > > > > > > > on
>> > > > sorted
>> > > > > > > reduce
>> > > > > > > > > > > - merge across nodes. Fundamentally, this is doable
>> > > > > > > > > > > since
>> > > > Lucene
>> > > > > > > > ranks
>> > > > > > > > > > > documents according to their score, and documents are
>> > > > returned in
>> > > > > > > the
>> > > > > > > > > > > order of their score. Since the scoring function is
>> > > > homogeneous,
>> > > > > > > this
>> > > > > > > > > > > means that across nodes, we can compare scores and
>> > > > > > > > > > > merge
>> > > > sort.
>> > > > > > > > > > >
>> > > > > > > > > > > Please let me know if I can take this up.
>> > > > > > > > > > >
>> > > > > > > > > > > Atri
>> > > > > > > > > > >
>> > > > > > > > > > > --
>> > > > > > > > > > > Regards,
>> > > > > > > > > > >
>> > > > > > > > > > > Atri
>> > > > > > > > > > > Apache Concerted
>> > > > > > > > > > >
>> > > > > > > > > >
>> > > > > > > > >
>> > > > > > > > >
>> > > > > > > > > --
>> > > > > > > > >
>> > > > > > > > > Best regards,
>> > > > > > > > > Alexei Scherbakov
>> > > > > > > >
>> > > > > > > > --
>> > > > > > > > Regards,
>> > > > > > > >
>> > > > > > > > Atri
>> > > > > > > > Apache Concerted
>> > > > > > > >
>> > > > > > >
>> > > > > >
>> > > > >
>> > > > >
>> > > > > --
>> > > > > Best regards,
>> > > > > Andrey V. Mashenkov
>> > > >
>> > > > --
>> > > > Regards,
>> > > >
>> > > > Atri
>> > > > Apache Concerted
>> > > >
>> > >
>> > >
>> > > --
>> > > Best regards,
>> > > Andrey V. Mashenkov
>> >
>> > --
>> > Regards,
>> >
>> > Atri
>> > Apache Concerted
>> >
>>
>>
>> --
>> Best regards,
>> Andrey V. Mashenkov
>
> --
> Regards,
>
> Atri
> Apache Concerted
>
--
Best regards,
Ivan Pavlukhin
Re: Text Queries Support
Posted by Kseniya Romanova <ks...@apache.org>.
I think we can invite them to our virtual meetup and share details. Your
thoughts?
чт, 28 окт. 2021 г. в 10:15, Ivan Pavlukhin <vo...@gmail.com>:
> Hi Maximiliano,
>
> Thank you for pointing this out, rather interesting. Have you tried to
> communicate with a hawkore team? I doubt that anyone in Community
> knows implementation details of hawkore additions.
>
> 2021-10-22 19:58 GMT+03:00, Maximiliano Gazquez <maximiliano.628@gmail.com
> >:
> > Hello everyone!
> >
> > I wanted to add this to the discussion.
> > I've found this project https://github.com/hawkore/ignite-hk which
> promises
> > to solve most of the issues that are being discussed here like
> pagination,
> > sorting and most important, persisting the lucene index.
> >
> > It does stuff like this to create indexes:
> >
> > CREATE INDEX PERSON_LUCENE_IDX ON "PUBLIC".PERSON(LUCENE)
> > FULLTEXT '{
> > ''refresh_seconds'':''60'',
> > ''directory_path'':'''',
> > ''ram_buffer_mb'':''10'',
> > ''max_cached_mb'':''-1'',
> > ''partitioner'':''{"type":"token","partitions":10}'',
> > ''optimizer_enabled'':''true'',
> > ''optimizer_schedule'':''0 1 * * *'',
> > ''version'':''0'',
> > ''schema'':''{
> > "default_analyzer":"english",
> >
> >
> "analyzers":{"my_custom_analyzer":{"type":"snowball","language":"Spanish","stopwords":"el,la,lo,loas,las,a,ante,bajo,cabe,con,contra"}},
> > "fields":{
> >
> >
> "duration":{"type":"date_range","from":"start_date","to":"stop_date","validated":false,"pattern":"yyyy/MM/dd"},
> >
> >
> "place":{"type":"geo_point","latitude":"latitude","longitude":"longitude"},
> > "date":{"type":"date","validated":true,"pattern":"yyyy/MM/dd"},
> > "number":{"type":"integer","validated":false,"boost":1.0},
> > "gender":{"type":"string","validated":true,"case_sensitive":true},
> > "bool":{"type":"boolean","validated":false},
> >
> >
> "phrase":{"type":"text","validated":false,"analyzer":"my_custom_analyzer"},
> > "name":{"type":"string","validated":false,"case_sensitive":true},
> > "animal":{"type":"string","validated":false,"case_sensitive":true},
> > "age":{"type":"integer","validated":false,"boost":1.0},
> > "food":{"type":"string","validated":false,"case_sensitive":true}
> > }
> > }''
> > }';
> >
> > And this to use that lucene index from inside SQL:
> >
> > SELECT * FROM "test".user
> > WHERE lucene = '{ query : {
> > type : "boolean",
> > must : [{type : "wildcard", field : "name",
> > value : "J*"},
> > {type : "wildcard", field : "food",
> > value : "tu*"}]}}';
> >
> > More examples here
> >
> https://github.com/hawkore/examples-apache-ignite-extensions/tree/master/examples-advanced-ignite-indexing
> >
> > I don't have anything to do with that company but it would be great to
> know
> > how they implemented this stuff.
> >
> >
> > On Mon, Aug 9, 2021 at 3:00 AM Ivan Pavlukhin <vo...@gmail.com>
> wrote:
> >
> >> Hi Atri,
> >>
> >> Sorry for a late answer.
> >>
> >> > I didn't quite understand. Are you proposing that Ignite should not
> >> > have
> >> FTS capabilities?
> >>
> >> It seems an option to me. IMHO it is better to have no FTS instead of
> >> something like current Ignite TextQueries.
> >>
> >> 2021-08-03 12:45 GMT+03:00, Atri Sharma <at...@apache.org>:
> >> > Hi Ivan,
> >> >
> >> > I didn't quite understand. Are you proposing that Ignite should not
> >> > have FTS capabilities?
> >> >
> >> > Atri
> >> >
> >> > On Tue, Aug 3, 2021 at 2:57 PM Ivan Pavlukhin <vo...@gmail.com>
> >> wrote:
> >> >>
> >> >> Hi Atri,
> >> >>
> >> >> My main concern is non-maleficence. Every task has several solutions,
> >> >> e.g. straightforward ones:
> >> >> 1. Do not implement FTS.
> >> >> 2. Create own implementation.
> >> >>
> >> >> Some of the strongest ones live without FTS [1].
> >> >>
> >> >> [1] https://github.com/cockroachdb/cockroach/issues/7821
> >> >>
> >> >> 2021-08-02 11:33 GMT+03:00, Atri Sharma <at...@apache.org>:
> >> >> > Hi Ivan,
> >> >> >
> >> >> > Would you like to propose an alternative to Lucene?
> >> >> >
> >> >> > Atri
> >> >> >
> >> >> > On Mon, 2 Aug 2021, 13:48 Ivan Pavlukhin, <vo...@gmail.com>
> >> wrote:
> >> >> >
> >> >> >> Folks,
> >> >> >>
> >> >> >> Sorry if read the thread not thoroughly enough, but do we consider
> >> >> >> Lucene as obviously right choice? In my understanding Ignite
> >> >> >> history
> >> >> >> has shown clearly that "fastest feature implementation" is not
> >> usually
> >> >> >> the best. And one example of this are text queries. Are not we
> >> >> >> trying
> >> >> >> to do a same mistake again? FTS is a huge feature, I do not
> believe
> >> >> >> there is an easy win for it.
> >> >> >>
> >> >> >> 2021-07-27 19:18 GMT+03:00, Atri Sharma <at...@apache.org>:
> >> >> >> > Andrey,
> >> >> >> >
> >> >> >> >> Per-partition Lucene index looks simple to implement, but it
> may
> >> >> >> >> require
> >> >> >> >> per-partition SQL to make full-text search expressions work
> >> >> >> >> correctly
> >> >> >> >> within the SQL quiery.
> >> >> >> > I think that as long as we follow the map - reduce process that
> >> >> >> > we
> >> >> >> > already do for other queries, we should be fine.
> >> >> >> >
> >> >> >> >> Per-partition SQL index may kill the performance. We already
> >> >> >> >> tried
> >> >> >> >> to
> >> >> >> >> do
> >> >> >> >> that in Ignite 2. However, QueryParallelism feature helps to
> >> >> >> >> speed
> >> >> >> >> up
> >> >> >> >> some
> >> >> >> >> data-intensive queries,
> >> >> >> >> but hits the performance in simple cases, and at some point
> >> >> >> >> (e.g.
> >> >> >> >> segments
> >> >> >> >> > number of CPU) the performance rapidly degrades with the
> >> >> >> >> > increasing
> >> >> >> >> number of segments.
> >> >> >> >
> >> >> >> > Yeah, that is always the case, but a global index will be a
> >> >> >> > nightmare
> >> >> >> > in terms of concurrency and pessimistic concurrency control will
> >> >> >> > anyways kill the benefits, coupled with the metadata
> >> >> >> > requirements.
> >> >> >> > What were the specific issues with per partition index?
> >> >> >> >>
> >> >> >> >> AFAIK, Lucene widely used bitmap indices that are easy to
> merge.
> >> >> >> >> Maybe, the map-reduce technique underneath FTS expressions and
> >> some
> >> >> >> hacks
> >> >> >> >> will add a minimal overhead.
> >> >> >> >
> >> >> >> > Lucene uses many types of indices but the aspect here is that
> per
> >> >> >> > partition Lucene indices can return docIDs and we can merge them
> >> >> >> > in
> >> >> >> > reduce phase. So we are abstracted out from specifics of the
> >> >> >> > internal
> >> >> >> > index being used to serve the query.
> >> >> >> >
> >> >> >> >>
> >> >> >> >> > As illustrated by Ilya, we can use Ignite's WAL records to
> >> >> >> >> > rebuild
> >> >> >> >> > Lucene indices. The important thing here is to not treat
> >> >> >> >> > Lucene
> >> >> >> >> > indices as source of truth.
> >> >> >> >> To use WAL we either should relay Lucene files to our Page
> >> >> >> >> memory
> >> >> >> >> or
> >> >> >> >> be
> >> >> >> >> aware of Lucene files structure.
> >> >> >> >> The first looks tricky, as we should guarantee a contiguous
> >> address
> >> >> >> space
> >> >> >> >> in Page memory for reflecting Lucene file. Maybe separate
> >> >> >> >> managed
> >> >> >> >> memory
> >> >> >> >> segment with its own rules?
> >> >> >> >
> >> >> >> > Why not use Lucene's MMappedDirectory and map it to our storage
> >> >> >> > classes?
> >> >> >> >
> >> >> >> >>
> >> >> >> >> >> Transactions.
> >> >> >> >> >> * Will we support transactions?
> >> >> >> >> > Lucene has no concept of transactions.
> >> >> >> >> Yes, but we have.
> >> >> >> >> Lucene index may be non-transactional, but users never expect
> to
> >> >> >> >> see
> >> >> >> >> uncommited data.
> >> >> >> >> How does this connect with transactional SQL?
> >> >> >> > We could have the Lucene writes done as a part of transactions
> >> >> >> > and
> >> >> >> > ack
> >> >> >> > back only when it succeeds/fails. WDYT?
> >> >> >> >>
> >> >> >> >> On Tue, Jul 27, 2021 at 1:36 PM Atri Sharma <at...@apache.org>
> >> >> >> >> wrote:
> >> >> >> >>
> >> >> >> >> > Sorry, I planned on creating a Wiki page for this, but it
> >> >> >> >> > makes
> >> >> >> >> > more
> >> >> >> >> > sense to be replying here.
> >> >> >> >> >
> >> >> >> >> > > * How Lucene index can be split among the nodes?
> >> >> >> >> >
> >> >> >> >> > We can have partition level indices on each node.
> >> >> >> >> >
> >> >> >> >> > > * If we'll have a single index for all partitions on the
> >> >> >> >> > > particular
> >> >> >> >> > > node,
> >> >> >> >> > > then how index records will be aware of partitioning?
> >> >> >> >> >
> >> >> >> >> > Index records dont need to be aware of partitioning -- each
> >> >> >> >> > Lucene
> >> >> >> >> > index is independent.
> >> >> >> >> >
> >> >> >> >> > > This is important to filter out backup records from the
> >> results
> >> >> >> >> > > to
> >> >> >> >> > > avoid
> >> >> >> >> > > duplicates.
> >> >> >> >> >
> >> >> >> >> > We can merge documents from different nodes and remove
> >> duplicates
> >> >> >> >> > as
> >> >> >> >> > long as docIDs are globally unique.
> >> >> >> >> >
> >> >> >> >> > > * How results from several nodes can be merged on the
> Reduce
> >> >> >> >> > > stage?
> >> >> >> >> >
> >> >> >> >> > As long as documents have a globally unique docID, Lucene has
> >> >> >> >> > merge
> >> >> >> >> > functions that can merge results from multiple partial
> >> >> >> >> > results.
> >> >> >> >> >
> >> >> >> >> > > * Does Lucene supports smth like JOIN operation or others
> >> >> >> >> > > that
> >> >> >> >> > > may
> >> >> >> >> > require
> >> >> >> >> > > data from another partition or index?
> >> >> >> >> >
> >> >> >> >> > As illustrated by Ilya, Block-Join works for us.
> >> >> >> >> >
> >> >> >> >> > > If so, then it likes to multistep query with merging
> results
> >> on
> >> >> >> >> > > intermediate stages and requires detailed investigation and
> >> >> >> >> > > design.
> >> >> >> >> > > It is ok if Ignite will have some limitations here, but we
> >> >> >> >> > > would
> >> >> >> like
> >> >> >> >> > > to
> >> >> >> >> > > know about them at the early stage.
> >> >> >> >> >
> >> >> >> >> > > * How effectively map Lucene files to the page memory? Is
> it
> >> >> >> >> > > even
> >> >> >> >> > possible?
> >> >> >> >> >
> >> >> >> >> > Lucene has PageDirectory implementations which allow storing
> >> >> >> >> > Lucene
> >> >> >> >> > indices on different kind of file structures. It has a
> >> >> >> >> > MMappedFileDirectory that we could use?
> >> >> >> >> >
> >> >> >> >> > > Otherwise, how to deal with potential OOM on large queries
> >> >> >> >> > > and
> >> >> >> memory
> >> >> >> >> > > capacity planning?
> >> >> >> >> >
> >> >> >> >> > We can use Lucene's MMapped directory.
> >> >> >> >> >
> >> >> >> >> > >
> >> >> >> >> > > Persistence.
> >> >> >> >> > > * How and what consistency guarantees could we have/expect?
> >> >> >> >> >
> >> >> >> >> > Lucene does not have WAL logs but is append only
> >> >> >> >> >
> >> >> >> >> > > Seems, we may not be able to write physical records for
> >> >> >> >> > > Lucene
> >> >> >> >> > > index
> >> >> >> >> > > to
> >> >> >> >> > our
> >> >> >> >> > > WAL. What can we do with this?
> >> >> >> >> >
> >> >> >> >> > As illustrated by Ilya, we can use Ignite's WAL records to
> >> >> >> >> > rebuild
> >> >> >> >> > Lucene indices. The important thing here is to not treat
> >> >> >> >> > Lucene
> >> >> >> >> > indices as source of truth.
> >> >> >> >> > >
> >> >> >> >> > > Transactions.
> >> >> >> >> > > * Will we support transactions?
> >> >> >> >> > Lucene has no concept of transactions.
> >> >> >> >> >
> >> >> >> >> > > * Should Lucene be aware of Transaction and track mvcc (or
> >> >> >> >> > > whatever)
> >> >> >> >> > > versions for the records?
> >> >> >> >> > No
> >> >> >> >> > > * What will be consistency guarantees?
> >> >> >> >> > We can acknowledge writes back only after Lucene index is
> >> >> >> >> > updated.
> >> >> >> >> > >
> >> >> >> >> > > UX
> >> >> >> >> > > * How to add FullText search queries syntax into Calcite?
> >> >> >> >> > Postgres's FTS functions are a good reference.
> >> >> >> >> > > * AFAIK, the Lucene index has many properties for tuning.
> >> >> >> >> > > How
> >> >> >> >> > > will
> >> >> >> >> > > the
> >> >> >> >> > user
> >> >> >> >> > > configure the index?
> >> >> >> >> > Most of those properties can be cluster level and exposed as
> a
> >> >> >> >> > new
> >> >> >> >> > sub
> >> >> >> >> > config for ignite.
> >> >> >> >> > > * How and where to store the settings? What are
> cluster-wide
> >> >> >> >> > > and
> >> >> >> what
> >> >> >> >> > > a
> >> >> >> >> > > local to the particular node?
> >> >> >> >> > All can be cluster level.
> >> >> >> >> > > * Will be all the settings immutable? Can be they changed
> >> >> >> >> > > on-fly?
> >> >> >> >> > > after
> >> >> >> >> > > node/grid restart?
> >> >> >> >> > They should be applied post restart.
> >> >> >> >> >
> >> >> >> >> > > * Any limitations on query syntax?
> >> >> >> >> > It depends on how we model our queries for text search.
> >> >> >> >> >
> >> >> >> >> > >
> >> >> >> >> > > SQL
> >> >> >> >> > > * Will we support FullText search in SQL?
> >> >> >> >> > We need custom functions for it. See Postgres's FTS
> functions.
> >> >> >> >> > > * How to integrate Lucene index into Calcite? What is the
> >> >> >> >> > > cost
> >> >> >> model?
> >> >> >> >> > There cannot be any cost model since there are no paths for a
> >> >> >> >> > text
> >> >> >> >> > query. If we see a text query, we have to use Lucene index or
> >> >> >> >> > return
> >> >> >> >> > an error. In this way, we need to model text search as a set
> >> >> >> >> > of
> >> >> >> >> > UDFs
> >> >> >> >> >
> >> >> >> >> > > Splitting rules? Traits?
> >> >> >> >> > Please see my reply above.
> >> >> >> >> > >
> >> >> >> >> > >
> >> >> >> >> > > With all of this, you can go with the IEP (or even some
> >> >> >> >> > > short
> >> >> >> >> > > summary)
> >> >> >> >> > and
> >> >> >> >> > > further POC and implementation.
> >> >> >> >> > > That's a big deal, so let's discuss what could be done
> here.
> >> >> >> >> > >
> >> >> >> >> > > On Fri, Jul 23, 2021 at 12:58 PM Atri Sharma
> >> >> >> >> > > <atri@apache.org
> >> >
> >> >> >> wrote:
> >> >> >> >> > >
> >> >> >> >> > > > I am actually happy to drive the feature for Ignite 3.
> FTS
> >> is
> >> >> >> >> > > > very
> >> >> >> >> > > > important for me and I think Ignite users will benefit
> >> >> >> >> > > > from
> >> >> >> >> > > > it
> >> >> >> >> > > > greatly.
> >> >> >> >> > > >
> >> >> >> >> > > > If it makes sense to be focusing on Ignite 3 for this
> >> >> >> >> > > > capability,
> >> >> >> I
> >> >> >> >> > > > am
> >> >> >> >> > > > eager to contribute there and lead the development.
> >> >> >> >> > > >
> >> >> >> >> > > > Please share your thoughts.
> >> >> >> >> > > >
> >> >> >> >> > > > On Fri, Jul 23, 2021 at 3:21 PM Andrey Mashenkov
> >> >> >> >> > > > <an...@gmail.com> wrote:
> >> >> >> >> > > > >
> >> >> >> >> > > > > Hi Atri,
> >> >> >> >> > > > >
> >> >> >> >> > > > > All the Jira tickets we have on the Full-text search
> >> >> >> >> > > > > (FTS)
> >> >> >> >> > > > > thing
> >> >> >> >> > > > > are
> >> >> >> >> > > > > targeted to Ignite 2.
> >> >> >> >> > > > >
> >> >> >> >> > > > > AFAIK, we want, but we have NOT committed to FTS
> support
> >> in
> >> >> >> Ignite
> >> >> >> >> > > > > 3,
> >> >> >> >> > > > yet.
> >> >> >> >> > > > > By the way, we are getting requests for this thing from
> >> the
> >> >> >> >> > > > > user
> >> >> >> >> > side,
> >> >> >> >> > > > and
> >> >> >> >> > > > > definitely,
> >> >> >> >> > > > > FTS would be a valuable feature for Ignite.
> >> >> >> >> > > > >
> >> >> >> >> > > > > It will be great if the one wants to drive it, any help
> >> >> >> >> > > > > will
> >> >> >> >> > > > > be
> >> >> >> >> > > > appreciated.
> >> >> >> >> > > > >
> >> >> >> >> > > > >
> >> >> >> >> > > > > On Fri, Jul 23, 2021 at 12:12 PM Atri Sharma
> >> >> >> >> > > > > <at...@apache.org>
> >> >> >> >> > wrote:
> >> >> >> >> > > > >
> >> >> >> >> > > > > > Hello,
> >> >> >> >> > > > > >
> >> >> >> >> > > > > > An update, please. I am working through persistence
> of
> >> >> >> >> > > > > > Lucene
> >> >> >> >> > > > > > index
> >> >> >> >> > > > using
> >> >> >> >> > > > > > Ignite Dictionary, and will be asking some questions
> >> >> >> >> > > > > > soon.
> >> >> >> >> > > > > >
> >> >> >> >> > > > > > I had one doubt - - where does this change go? Ignite
> >> >> >> >> > > > > > 3?
> >> >> >> >> > > > > >
> >> >> >> >> > > > > > Also, I know we want to build native support for text
> >> >> >> >> > > > > > searches
> >> >> >> >> > > > > > in
> >> >> >> >> > > > Ignite 3.
> >> >> >> >> > > > > > Is the work I am proposing here part of that, or will
> >> >> >> >> > > > > > that
> >> >> >> >> > > > > > be
> >> >> >> a
> >> >> >> >> > > > separate
> >> >> >> >> > > > > > effort?
> >> >> >> >> > > > > >
> >> >> >> >> > > > > > On Mon, 28 Jun 2021, 19:20 Ilya Kasnacheev, <
> >> >> >> >> > ilya.kasnacheev@gmail.com
> >> >> >> >> > > > >
> >> >> >> >> > > > > > wrote:
> >> >> >> >> > > > > >
> >> >> >> >> > > > > > > Hello!
> >> >> >> >> > > > > > >
> >> >> >> >> > > > > > > I think that number one is the most important one,
> >> then
> >> >> >> maybe
> >> >> >> >> > > > > > > it
> >> >> >> >> > > > will see
> >> >> >> >> > > > > > > more use and other deficiencies become more
> >> >> >> >> > > > > > > apparent,
> >> >> >> leading
> >> >> >> >> > > > > > > to
> >> >> >> >> > more
> >> >> >> >> > > > > > > tickets and visibility.
> >> >> >> >> > > > > > >
> >> >> >> >> > > > > > > Maybe 2. and 3. will even use a different approach
> >> when
> >> >> >> >> > persistence
> >> >> >> >> > > > is
> >> >> >> >> > > > > > > implemented.
> >> >> >> >> > > > > > >
> >> >> >> >> > > > > > > Regards,
> >> >> >> >> > > > > > > --
> >> >> >> >> > > > > > > Ilya Kasnacheev
> >> >> >> >> > > > > > >
> >> >> >> >> > > > > > >
> >> >> >> >> > > > > > > пн, 28 июн. 2021 г. в 14:34, Atri Sharma
> >> >> >> >> > > > > > > <at...@apache.org>:
> >> >> >> >> > > > > > >
> >> >> >> >> > > > > > > > Hello Again!
> >> >> >> >> > > > > > > >
> >> >> >> >> > > > > > > > I have been looking into the aforementioned and
> >> >> >> >> > > > > > > > here
> >> >> >> >> > > > > > > > are
> >> >> >> my
> >> >> >> >> > follow
> >> >> >> >> > > > up
> >> >> >> >> > > > > > > > thoughts:
> >> >> >> >> > > > > > > >
> >> >> >> >> > > > > > > > 1. Support persistence of Lucene indexes.
> >> >> >> >> > > > > > > > 2.
> >> https://issues.apache.org/jira/browse/IGNITE-12401
> >> >> >> >> > > > > > > > (Needs
> >> >> >> >> > > > fixing of
> >> >> >> >> > > > > > > > moving partitions first)
> >> >> >> >> > > > > > > > 3. Figure out how to return scores from nodes and
> >> use
> >> >> >> >> > > > > > > > them
> >> >> >> >> > > > > > > > as
> >> >> >> >> > sort
> >> >> >> >> > > > > > > > parameters on the coordinator node
> >> >> >> >> > > > > > > > (
> https://issues.apache.org/jira/browse/IGNITE-12291
> >> )
> >> >> >> >> > > > > > > >
> >> >> >> >> > > > > > > > Please let me know if this looks ok to make text
> >> >> >> >> > > > > > > > queries
> >> >> >> >> > > > functional?
> >> >> >> >> > > > > > > >
> >> >> >> >> > > > > > > > Atri
> >> >> >> >> > > > > > > >
> >> >> >> >> > > > > > > > On Mon, Jun 21, 2021 at 2:49 PM Alexei Scherbakov
> >> >> >> >> > > > > > > > <al...@gmail.com> wrote:
> >> >> >> >> > > > > > > > >
> >> >> >> >> > > > > > > > > Hi.
> >> >> >> >> > > > > > > > >
> >> >> >> >> > > > > > > > > One of the biggest issues with text queries is
> a
> >> >> >> >> > > > > > > > > lack
> >> >> >> >> > > > > > > > > of
> >> >> >> >> > support
> >> >> >> >> > > > for
> >> >> >> >> > > > > > > > lucene
> >> >> >> >> > > > > > > > > indices persistence, which makes this
> >> functionality
> >> >> >> >> > > > > > > > > useless
> >> >> >> >> > if a
> >> >> >> >> > > > > > > > > persistence is enabled.
> >> >> >> >> > > > > > > > >
> >> >> >> >> > > > > > > > > I would first take care of it.
> >> >> >> >> > > > > > > > >
> >> >> >> >> > > > > > > > > пн, 21 июн. 2021 г. в 12:16, Maksim Timonin <
> >> >> >> >> > > > timonin.maxim@gmail.com
> >> >> >> >> > > > > > >:
> >> >> >> >> > > > > > > > >
> >> >> >> >> > > > > > > > > > Hi, Atri!
> >> >> >> >> > > > > > > > > >
> >> >> >> >> > > > > > > > > > You're right, Actually there is a lack of
> >> support
> >> >> >> >> > > > > > > > > > for
> >> >> >> >> > > > TextQueries.
> >> >> >> >> > > > > > > For
> >> >> >> >> > > > > > > > the
> >> >> >> >> > > > > > > > > > last ticket I'm doing I see some obvious
> >> >> >> >> > > > > > > > > > issues
> >> >> >> >> > > > > > > > > > with
> >> >> >> >> > > > > > > > > > them
> >> >> >> >> > (no
> >> >> >> >> > > > page
> >> >> >> >> > > > > > > size
> >> >> >> >> > > > > > > > > > support, for example). I'm glad that somebody
> >> >> >> >> > > > > > > > > > wants
> >> >> >> >> > > > > > > > > > to
> >> >> >> >> > maintain
> >> >> >> >> > > > > > this
> >> >> >> >> > > > > > > > > > functionality. Thanks a lot!
> >> >> >> >> > > > > > > > > >
> >> >> >> >> > > > > > > > > > For the MergeSort algorithm there is already
> a
> >> >> >> >> > > > > > > > > > patch
> >> >> >> >> > > > > > > > > > for
> >> >> >> >> > that
> >> >> >> >> > > > [1].
> >> >> >> >> > > > > > > It's
> >> >> >> >> > > > > > > > > > currently on review. This patch introduces an
> >> >> >> >> > > > > > > > > > abstract
> >> >> >> >> > reducer
> >> >> >> >> > > > for
> >> >> >> >> > > > > > > > > > CacheQueries with 2 implementations
> >> >> >> >> > > > > > > > > > (unordered,
> >> >> >> >> > merge-sort).
> >> >> >> >> > > > Then
> >> >> >> >> > > > > > > > TextQuery
> >> >> >> >> > > > > > > > > > leverages on MergeSort to order results from
> >> >> >> >> > > > > > > > > > multiple
> >> >> >> >> > nodes by
> >> >> >> >> > > > > > score.
> >> >> >> >> > > > > > > > This
> >> >> >> >> > > > > > > > > > patch also fixes the pageSize issue, I've
> >> >> >> >> > > > > > > > > > mentioned
> >> >> >> >> > > > > > > > > > before.
> >> >> >> >> > > > Could
> >> >> >> >> > > > > > you
> >> >> >> >> > > > > > > > > > please check if it fully matches your idea?
> >> >> >> >> > > > > > > > > > Any
> >> >> >> >> > > > > > > > > > issues
> >> >> >> >> > > > > > > > > > or
> >> >> >> >> > > > comments
> >> >> >> >> > > > > > > are
> >> >> >> >> > > > > > > > > > welcome.
> >> >> >> >> > > > > > > > > >
> >> >> >> >> > > > > > > > > > I've prepared this ticket, because I need the
> >> >> >> MergeSort
> >> >> >> >> > > > algorithm
> >> >> >> >> > > > > > for
> >> >> >> >> > > > > > > > the
> >> >> >> >> > > > > > > > > > new type of queries I'm implementing
> >> (IndexQuery,
> >> >> >> >> > > > > > > > > > it
> >> >> >> >> > > > > > > > > > should
> >> >> >> >> > > > also
> >> >> >> >> > > > > > > > provide
> >> >> >> >> > > > > > > > > > ordered results over multiple nodes).
> >> >> >> >> > > > > > > > > > Currently
> >> >> >> >> > > > > > > > > > I'm
> >> >> >> not
> >> >> >> >> > > > planning to
> >> >> >> >> > > > > > > go
> >> >> >> >> > > > > > > > > > further with TextQuery, so if you're going to
> >> >> >> >> > > > > > > > > > support
> >> >> >> >> > > > > > > > > > this
> >> >> >> >> > > > it'll
> >> >> >> >> > > > > > be a
> >> >> >> >> > > > > > > > great
> >> >> >> >> > > > > > > > > > contribution, I think.
> >> >> >> >> > > > > > > > > >
> >> >> >> >> > > > > > > > > > [1]
> >> >> >> https://issues.apache.org/jira/browse/IGNITE-14703
> >> >> >> >> > > > > > > > > > [2]
> https://github.com/apache/ignite/pull/9081
> >> >> >> >> > > > > > > > > >
> >> >> >> >> > > > > > > > > >
> >> >> >> >> > > > > > > > > > On Mon, Jun 21, 2021 at 11:11 AM Atri Sharma
> <
> >> >> >> >> > atri@apache.org>
> >> >> >> >> > > > > > > wrote:
> >> >> >> >> > > > > > > > > >
> >> >> >> >> > > > > > > > > > > Hi All,
> >> >> >> >> > > > > > > > > > >
> >> >> >> >> > > > > > > > > > > I have been looking into our text queries
> >> >> >> >> > > > > > > > > > > support
> >> >> >> and
> >> >> >> >> > > > > > > > > > > see
> >> >> >> >> > > > that it
> >> >> >> >> > > > > > > has
> >> >> >> >> > > > > > > > > > > limited community support.
> >> >> >> >> > > > > > > > > > >
> >> >> >> >> > > > > > > > > > > Therefore, I volunteer to be the maintainer
> >> >> >> >> > > > > > > > > > > of
> >> >> >> >> > > > > > > > > > > the
> >> >> >> >> > module and
> >> >> >> >> > > > > > work
> >> >> >> >> > > > > > > on
> >> >> >> >> > > > > > > > > > > enhancing it further.
> >> >> >> >> > > > > > > > > > >
> >> >> >> >> > > > > > > > > > > First goal would be to move to Lucene 8.x,
> >> then
> >> >> >> >> > > > > > > > > > > work
> >> >> >> >> > > > > > > > > > > on
> >> >> >> >> > > > sorted
> >> >> >> >> > > > > > > reduce
> >> >> >> >> > > > > > > > > > > - merge across nodes. Fundamentally, this
> is
> >> >> >> >> > > > > > > > > > > doable
> >> >> >> >> > > > > > > > > > > since
> >> >> >> >> > > > Lucene
> >> >> >> >> > > > > > > > ranks
> >> >> >> >> > > > > > > > > > > documents according to their score, and
> >> >> >> >> > > > > > > > > > > documents
> >> >> >> are
> >> >> >> >> > > > returned in
> >> >> >> >> > > > > > > the
> >> >> >> >> > > > > > > > > > > order of their score. Since the scoring
> >> >> >> >> > > > > > > > > > > function
> >> >> >> >> > > > > > > > > > > is
> >> >> >> >> > > > homogeneous,
> >> >> >> >> > > > > > > this
> >> >> >> >> > > > > > > > > > > means that across nodes, we can compare
> >> >> >> >> > > > > > > > > > > scores
> >> >> >> >> > > > > > > > > > > and
> >> >> >> >> > > > > > > > > > > merge
> >> >> >> >> > > > sort.
> >> >> >> >> > > > > > > > > > >
> >> >> >> >> > > > > > > > > > > Please let me know if I can take this up.
> >> >> >> >> > > > > > > > > > >
> >> >> >> >> > > > > > > > > > > Atri
> >> >> >> >> > > > > > > > > > >
> >> >> >> >> > > > > > > > > > > --
> >> >> >> >> > > > > > > > > > > Regards,
> >> >> >> >> > > > > > > > > > >
> >> >> >> >> > > > > > > > > > > Atri
> >> >> >> >> > > > > > > > > > > Apache Concerted
> >> >> >> >> > > > > > > > > > >
> >> >> >> >> > > > > > > > > >
> >> >> >> >> > > > > > > > >
> >> >> >> >> > > > > > > > >
> >> >> >> >> > > > > > > > > --
> >> >> >> >> > > > > > > > >
> >> >> >> >> > > > > > > > > Best regards,
> >> >> >> >> > > > > > > > > Alexei Scherbakov
> >> >> >> >> > > > > > > >
> >> >> >> >> > > > > > > > --
> >> >> >> >> > > > > > > > Regards,
> >> >> >> >> > > > > > > >
> >> >> >> >> > > > > > > > Atri
> >> >> >> >> > > > > > > > Apache Concerted
> >> >> >> >> > > > > > > >
> >> >> >> >> > > > > > >
> >> >> >> >> > > > > >
> >> >> >> >> > > > >
> >> >> >> >> > > > >
> >> >> >> >> > > > > --
> >> >> >> >> > > > > Best regards,
> >> >> >> >> > > > > Andrey V. Mashenkov
> >> >> >> >> > > >
> >> >> >> >> > > > --
> >> >> >> >> > > > Regards,
> >> >> >> >> > > >
> >> >> >> >> > > > Atri
> >> >> >> >> > > > Apache Concerted
> >> >> >> >> > > >
> >> >> >> >> > >
> >> >> >> >> > >
> >> >> >> >> > > --
> >> >> >> >> > > Best regards,
> >> >> >> >> > > Andrey V. Mashenkov
> >> >> >> >> >
> >> >> >> >> > --
> >> >> >> >> > Regards,
> >> >> >> >> >
> >> >> >> >> > Atri
> >> >> >> >> > Apache Concerted
> >> >> >> >> >
> >> >> >> >>
> >> >> >> >>
> >> >> >> >> --
> >> >> >> >> Best regards,
> >> >> >> >> Andrey V. Mashenkov
> >> >> >> >
> >> >> >> > --
> >> >> >> > Regards,
> >> >> >> >
> >> >> >> > Atri
> >> >> >> > Apache Concerted
> >> >> >> >
> >> >> >>
> >> >> >>
> >> >> >> --
> >> >> >>
> >> >> >> Best regards,
> >> >> >> Ivan Pavlukhin
> >> >> >>
> >> >> >
> >> >>
> >> >>
> >> >> --
> >> >>
> >> >> Best regards,
> >> >> Ivan Pavlukhin
> >> >
> >> > --
> >> > Regards,
> >> >
> >> > Atri
> >> > Apache Concerted
> >> >
> >>
> >>
> >> --
> >>
> >> Best regards,
> >> Ivan Pavlukhin
> >>
> >
>
>
> --
>
> Best regards,
> Ivan Pavlukhin
>
Re: Text Queries Support
Posted by Ivan Pavlukhin <vo...@gmail.com>.
Hi Maximiliano,
Thank you for pointing this out, rather interesting. Have you tried to
communicate with a hawkore team? I doubt that anyone in Community
knows implementation details of hawkore additions.
2021-10-22 19:58 GMT+03:00, Maximiliano Gazquez <ma...@gmail.com>:
> Hello everyone!
>
> I wanted to add this to the discussion.
> I've found this project https://github.com/hawkore/ignite-hk which promises
> to solve most of the issues that are being discussed here like pagination,
> sorting and most important, persisting the lucene index.
>
> It does stuff like this to create indexes:
>
> CREATE INDEX PERSON_LUCENE_IDX ON "PUBLIC".PERSON(LUCENE)
> FULLTEXT '{
> ''refresh_seconds'':''60'',
> ''directory_path'':'''',
> ''ram_buffer_mb'':''10'',
> ''max_cached_mb'':''-1'',
> ''partitioner'':''{"type":"token","partitions":10}'',
> ''optimizer_enabled'':''true'',
> ''optimizer_schedule'':''0 1 * * *'',
> ''version'':''0'',
> ''schema'':''{
> "default_analyzer":"english",
>
> "analyzers":{"my_custom_analyzer":{"type":"snowball","language":"Spanish","stopwords":"el,la,lo,loas,las,a,ante,bajo,cabe,con,contra"}},
> "fields":{
>
> "duration":{"type":"date_range","from":"start_date","to":"stop_date","validated":false,"pattern":"yyyy/MM/dd"},
>
> "place":{"type":"geo_point","latitude":"latitude","longitude":"longitude"},
> "date":{"type":"date","validated":true,"pattern":"yyyy/MM/dd"},
> "number":{"type":"integer","validated":false,"boost":1.0},
> "gender":{"type":"string","validated":true,"case_sensitive":true},
> "bool":{"type":"boolean","validated":false},
>
> "phrase":{"type":"text","validated":false,"analyzer":"my_custom_analyzer"},
> "name":{"type":"string","validated":false,"case_sensitive":true},
> "animal":{"type":"string","validated":false,"case_sensitive":true},
> "age":{"type":"integer","validated":false,"boost":1.0},
> "food":{"type":"string","validated":false,"case_sensitive":true}
> }
> }''
> }';
>
> And this to use that lucene index from inside SQL:
>
> SELECT * FROM "test".user
> WHERE lucene = '{ query : {
> type : "boolean",
> must : [{type : "wildcard", field : "name",
> value : "J*"},
> {type : "wildcard", field : "food",
> value : "tu*"}]}}';
>
> More examples here
> https://github.com/hawkore/examples-apache-ignite-extensions/tree/master/examples-advanced-ignite-indexing
>
> I don't have anything to do with that company but it would be great to know
> how they implemented this stuff.
>
>
> On Mon, Aug 9, 2021 at 3:00 AM Ivan Pavlukhin <vo...@gmail.com> wrote:
>
>> Hi Atri,
>>
>> Sorry for a late answer.
>>
>> > I didn't quite understand. Are you proposing that Ignite should not
>> > have
>> FTS capabilities?
>>
>> It seems an option to me. IMHO it is better to have no FTS instead of
>> something like current Ignite TextQueries.
>>
>> 2021-08-03 12:45 GMT+03:00, Atri Sharma <at...@apache.org>:
>> > Hi Ivan,
>> >
>> > I didn't quite understand. Are you proposing that Ignite should not
>> > have FTS capabilities?
>> >
>> > Atri
>> >
>> > On Tue, Aug 3, 2021 at 2:57 PM Ivan Pavlukhin <vo...@gmail.com>
>> wrote:
>> >>
>> >> Hi Atri,
>> >>
>> >> My main concern is non-maleficence. Every task has several solutions,
>> >> e.g. straightforward ones:
>> >> 1. Do not implement FTS.
>> >> 2. Create own implementation.
>> >>
>> >> Some of the strongest ones live without FTS [1].
>> >>
>> >> [1] https://github.com/cockroachdb/cockroach/issues/7821
>> >>
>> >> 2021-08-02 11:33 GMT+03:00, Atri Sharma <at...@apache.org>:
>> >> > Hi Ivan,
>> >> >
>> >> > Would you like to propose an alternative to Lucene?
>> >> >
>> >> > Atri
>> >> >
>> >> > On Mon, 2 Aug 2021, 13:48 Ivan Pavlukhin, <vo...@gmail.com>
>> wrote:
>> >> >
>> >> >> Folks,
>> >> >>
>> >> >> Sorry if read the thread not thoroughly enough, but do we consider
>> >> >> Lucene as obviously right choice? In my understanding Ignite
>> >> >> history
>> >> >> has shown clearly that "fastest feature implementation" is not
>> usually
>> >> >> the best. And one example of this are text queries. Are not we
>> >> >> trying
>> >> >> to do a same mistake again? FTS is a huge feature, I do not believe
>> >> >> there is an easy win for it.
>> >> >>
>> >> >> 2021-07-27 19:18 GMT+03:00, Atri Sharma <at...@apache.org>:
>> >> >> > Andrey,
>> >> >> >
>> >> >> >> Per-partition Lucene index looks simple to implement, but it may
>> >> >> >> require
>> >> >> >> per-partition SQL to make full-text search expressions work
>> >> >> >> correctly
>> >> >> >> within the SQL quiery.
>> >> >> > I think that as long as we follow the map - reduce process that
>> >> >> > we
>> >> >> > already do for other queries, we should be fine.
>> >> >> >
>> >> >> >> Per-partition SQL index may kill the performance. We already
>> >> >> >> tried
>> >> >> >> to
>> >> >> >> do
>> >> >> >> that in Ignite 2. However, QueryParallelism feature helps to
>> >> >> >> speed
>> >> >> >> up
>> >> >> >> some
>> >> >> >> data-intensive queries,
>> >> >> >> but hits the performance in simple cases, and at some point
>> >> >> >> (e.g.
>> >> >> >> segments
>> >> >> >> > number of CPU) the performance rapidly degrades with the
>> >> >> >> > increasing
>> >> >> >> number of segments.
>> >> >> >
>> >> >> > Yeah, that is always the case, but a global index will be a
>> >> >> > nightmare
>> >> >> > in terms of concurrency and pessimistic concurrency control will
>> >> >> > anyways kill the benefits, coupled with the metadata
>> >> >> > requirements.
>> >> >> > What were the specific issues with per partition index?
>> >> >> >>
>> >> >> >> AFAIK, Lucene widely used bitmap indices that are easy to merge.
>> >> >> >> Maybe, the map-reduce technique underneath FTS expressions and
>> some
>> >> >> hacks
>> >> >> >> will add a minimal overhead.
>> >> >> >
>> >> >> > Lucene uses many types of indices but the aspect here is that per
>> >> >> > partition Lucene indices can return docIDs and we can merge them
>> >> >> > in
>> >> >> > reduce phase. So we are abstracted out from specifics of the
>> >> >> > internal
>> >> >> > index being used to serve the query.
>> >> >> >
>> >> >> >>
>> >> >> >> > As illustrated by Ilya, we can use Ignite's WAL records to
>> >> >> >> > rebuild
>> >> >> >> > Lucene indices. The important thing here is to not treat
>> >> >> >> > Lucene
>> >> >> >> > indices as source of truth.
>> >> >> >> To use WAL we either should relay Lucene files to our Page
>> >> >> >> memory
>> >> >> >> or
>> >> >> >> be
>> >> >> >> aware of Lucene files structure.
>> >> >> >> The first looks tricky, as we should guarantee a contiguous
>> address
>> >> >> space
>> >> >> >> in Page memory for reflecting Lucene file. Maybe separate
>> >> >> >> managed
>> >> >> >> memory
>> >> >> >> segment with its own rules?
>> >> >> >
>> >> >> > Why not use Lucene's MMappedDirectory and map it to our storage
>> >> >> > classes?
>> >> >> >
>> >> >> >>
>> >> >> >> >> Transactions.
>> >> >> >> >> * Will we support transactions?
>> >> >> >> > Lucene has no concept of transactions.
>> >> >> >> Yes, but we have.
>> >> >> >> Lucene index may be non-transactional, but users never expect to
>> >> >> >> see
>> >> >> >> uncommited data.
>> >> >> >> How does this connect with transactional SQL?
>> >> >> > We could have the Lucene writes done as a part of transactions
>> >> >> > and
>> >> >> > ack
>> >> >> > back only when it succeeds/fails. WDYT?
>> >> >> >>
>> >> >> >> On Tue, Jul 27, 2021 at 1:36 PM Atri Sharma <at...@apache.org>
>> >> >> >> wrote:
>> >> >> >>
>> >> >> >> > Sorry, I planned on creating a Wiki page for this, but it
>> >> >> >> > makes
>> >> >> >> > more
>> >> >> >> > sense to be replying here.
>> >> >> >> >
>> >> >> >> > > * How Lucene index can be split among the nodes?
>> >> >> >> >
>> >> >> >> > We can have partition level indices on each node.
>> >> >> >> >
>> >> >> >> > > * If we'll have a single index for all partitions on the
>> >> >> >> > > particular
>> >> >> >> > > node,
>> >> >> >> > > then how index records will be aware of partitioning?
>> >> >> >> >
>> >> >> >> > Index records dont need to be aware of partitioning -- each
>> >> >> >> > Lucene
>> >> >> >> > index is independent.
>> >> >> >> >
>> >> >> >> > > This is important to filter out backup records from the
>> results
>> >> >> >> > > to
>> >> >> >> > > avoid
>> >> >> >> > > duplicates.
>> >> >> >> >
>> >> >> >> > We can merge documents from different nodes and remove
>> duplicates
>> >> >> >> > as
>> >> >> >> > long as docIDs are globally unique.
>> >> >> >> >
>> >> >> >> > > * How results from several nodes can be merged on the Reduce
>> >> >> >> > > stage?
>> >> >> >> >
>> >> >> >> > As long as documents have a globally unique docID, Lucene has
>> >> >> >> > merge
>> >> >> >> > functions that can merge results from multiple partial
>> >> >> >> > results.
>> >> >> >> >
>> >> >> >> > > * Does Lucene supports smth like JOIN operation or others
>> >> >> >> > > that
>> >> >> >> > > may
>> >> >> >> > require
>> >> >> >> > > data from another partition or index?
>> >> >> >> >
>> >> >> >> > As illustrated by Ilya, Block-Join works for us.
>> >> >> >> >
>> >> >> >> > > If so, then it likes to multistep query with merging results
>> on
>> >> >> >> > > intermediate stages and requires detailed investigation and
>> >> >> >> > > design.
>> >> >> >> > > It is ok if Ignite will have some limitations here, but we
>> >> >> >> > > would
>> >> >> like
>> >> >> >> > > to
>> >> >> >> > > know about them at the early stage.
>> >> >> >> >
>> >> >> >> > > * How effectively map Lucene files to the page memory? Is it
>> >> >> >> > > even
>> >> >> >> > possible?
>> >> >> >> >
>> >> >> >> > Lucene has PageDirectory implementations which allow storing
>> >> >> >> > Lucene
>> >> >> >> > indices on different kind of file structures. It has a
>> >> >> >> > MMappedFileDirectory that we could use?
>> >> >> >> >
>> >> >> >> > > Otherwise, how to deal with potential OOM on large queries
>> >> >> >> > > and
>> >> >> memory
>> >> >> >> > > capacity planning?
>> >> >> >> >
>> >> >> >> > We can use Lucene's MMapped directory.
>> >> >> >> >
>> >> >> >> > >
>> >> >> >> > > Persistence.
>> >> >> >> > > * How and what consistency guarantees could we have/expect?
>> >> >> >> >
>> >> >> >> > Lucene does not have WAL logs but is append only
>> >> >> >> >
>> >> >> >> > > Seems, we may not be able to write physical records for
>> >> >> >> > > Lucene
>> >> >> >> > > index
>> >> >> >> > > to
>> >> >> >> > our
>> >> >> >> > > WAL. What can we do with this?
>> >> >> >> >
>> >> >> >> > As illustrated by Ilya, we can use Ignite's WAL records to
>> >> >> >> > rebuild
>> >> >> >> > Lucene indices. The important thing here is to not treat
>> >> >> >> > Lucene
>> >> >> >> > indices as source of truth.
>> >> >> >> > >
>> >> >> >> > > Transactions.
>> >> >> >> > > * Will we support transactions?
>> >> >> >> > Lucene has no concept of transactions.
>> >> >> >> >
>> >> >> >> > > * Should Lucene be aware of Transaction and track mvcc (or
>> >> >> >> > > whatever)
>> >> >> >> > > versions for the records?
>> >> >> >> > No
>> >> >> >> > > * What will be consistency guarantees?
>> >> >> >> > We can acknowledge writes back only after Lucene index is
>> >> >> >> > updated.
>> >> >> >> > >
>> >> >> >> > > UX
>> >> >> >> > > * How to add FullText search queries syntax into Calcite?
>> >> >> >> > Postgres's FTS functions are a good reference.
>> >> >> >> > > * AFAIK, the Lucene index has many properties for tuning.
>> >> >> >> > > How
>> >> >> >> > > will
>> >> >> >> > > the
>> >> >> >> > user
>> >> >> >> > > configure the index?
>> >> >> >> > Most of those properties can be cluster level and exposed as a
>> >> >> >> > new
>> >> >> >> > sub
>> >> >> >> > config for ignite.
>> >> >> >> > > * How and where to store the settings? What are cluster-wide
>> >> >> >> > > and
>> >> >> what
>> >> >> >> > > a
>> >> >> >> > > local to the particular node?
>> >> >> >> > All can be cluster level.
>> >> >> >> > > * Will be all the settings immutable? Can be they changed
>> >> >> >> > > on-fly?
>> >> >> >> > > after
>> >> >> >> > > node/grid restart?
>> >> >> >> > They should be applied post restart.
>> >> >> >> >
>> >> >> >> > > * Any limitations on query syntax?
>> >> >> >> > It depends on how we model our queries for text search.
>> >> >> >> >
>> >> >> >> > >
>> >> >> >> > > SQL
>> >> >> >> > > * Will we support FullText search in SQL?
>> >> >> >> > We need custom functions for it. See Postgres's FTS functions.
>> >> >> >> > > * How to integrate Lucene index into Calcite? What is the
>> >> >> >> > > cost
>> >> >> model?
>> >> >> >> > There cannot be any cost model since there are no paths for a
>> >> >> >> > text
>> >> >> >> > query. If we see a text query, we have to use Lucene index or
>> >> >> >> > return
>> >> >> >> > an error. In this way, we need to model text search as a set
>> >> >> >> > of
>> >> >> >> > UDFs
>> >> >> >> >
>> >> >> >> > > Splitting rules? Traits?
>> >> >> >> > Please see my reply above.
>> >> >> >> > >
>> >> >> >> > >
>> >> >> >> > > With all of this, you can go with the IEP (or even some
>> >> >> >> > > short
>> >> >> >> > > summary)
>> >> >> >> > and
>> >> >> >> > > further POC and implementation.
>> >> >> >> > > That's a big deal, so let's discuss what could be done here.
>> >> >> >> > >
>> >> >> >> > > On Fri, Jul 23, 2021 at 12:58 PM Atri Sharma
>> >> >> >> > > <atri@apache.org
>> >
>> >> >> wrote:
>> >> >> >> > >
>> >> >> >> > > > I am actually happy to drive the feature for Ignite 3. FTS
>> is
>> >> >> >> > > > very
>> >> >> >> > > > important for me and I think Ignite users will benefit
>> >> >> >> > > > from
>> >> >> >> > > > it
>> >> >> >> > > > greatly.
>> >> >> >> > > >
>> >> >> >> > > > If it makes sense to be focusing on Ignite 3 for this
>> >> >> >> > > > capability,
>> >> >> I
>> >> >> >> > > > am
>> >> >> >> > > > eager to contribute there and lead the development.
>> >> >> >> > > >
>> >> >> >> > > > Please share your thoughts.
>> >> >> >> > > >
>> >> >> >> > > > On Fri, Jul 23, 2021 at 3:21 PM Andrey Mashenkov
>> >> >> >> > > > <an...@gmail.com> wrote:
>> >> >> >> > > > >
>> >> >> >> > > > > Hi Atri,
>> >> >> >> > > > >
>> >> >> >> > > > > All the Jira tickets we have on the Full-text search
>> >> >> >> > > > > (FTS)
>> >> >> >> > > > > thing
>> >> >> >> > > > > are
>> >> >> >> > > > > targeted to Ignite 2.
>> >> >> >> > > > >
>> >> >> >> > > > > AFAIK, we want, but we have NOT committed to FTS support
>> in
>> >> >> Ignite
>> >> >> >> > > > > 3,
>> >> >> >> > > > yet.
>> >> >> >> > > > > By the way, we are getting requests for this thing from
>> the
>> >> >> >> > > > > user
>> >> >> >> > side,
>> >> >> >> > > > and
>> >> >> >> > > > > definitely,
>> >> >> >> > > > > FTS would be a valuable feature for Ignite.
>> >> >> >> > > > >
>> >> >> >> > > > > It will be great if the one wants to drive it, any help
>> >> >> >> > > > > will
>> >> >> >> > > > > be
>> >> >> >> > > > appreciated.
>> >> >> >> > > > >
>> >> >> >> > > > >
>> >> >> >> > > > > On Fri, Jul 23, 2021 at 12:12 PM Atri Sharma
>> >> >> >> > > > > <at...@apache.org>
>> >> >> >> > wrote:
>> >> >> >> > > > >
>> >> >> >> > > > > > Hello,
>> >> >> >> > > > > >
>> >> >> >> > > > > > An update, please. I am working through persistence of
>> >> >> >> > > > > > Lucene
>> >> >> >> > > > > > index
>> >> >> >> > > > using
>> >> >> >> > > > > > Ignite Dictionary, and will be asking some questions
>> >> >> >> > > > > > soon.
>> >> >> >> > > > > >
>> >> >> >> > > > > > I had one doubt - - where does this change go? Ignite
>> >> >> >> > > > > > 3?
>> >> >> >> > > > > >
>> >> >> >> > > > > > Also, I know we want to build native support for text
>> >> >> >> > > > > > searches
>> >> >> >> > > > > > in
>> >> >> >> > > > Ignite 3.
>> >> >> >> > > > > > Is the work I am proposing here part of that, or will
>> >> >> >> > > > > > that
>> >> >> >> > > > > > be
>> >> >> a
>> >> >> >> > > > separate
>> >> >> >> > > > > > effort?
>> >> >> >> > > > > >
>> >> >> >> > > > > > On Mon, 28 Jun 2021, 19:20 Ilya Kasnacheev, <
>> >> >> >> > ilya.kasnacheev@gmail.com
>> >> >> >> > > > >
>> >> >> >> > > > > > wrote:
>> >> >> >> > > > > >
>> >> >> >> > > > > > > Hello!
>> >> >> >> > > > > > >
>> >> >> >> > > > > > > I think that number one is the most important one,
>> then
>> >> >> maybe
>> >> >> >> > > > > > > it
>> >> >> >> > > > will see
>> >> >> >> > > > > > > more use and other deficiencies become more
>> >> >> >> > > > > > > apparent,
>> >> >> leading
>> >> >> >> > > > > > > to
>> >> >> >> > more
>> >> >> >> > > > > > > tickets and visibility.
>> >> >> >> > > > > > >
>> >> >> >> > > > > > > Maybe 2. and 3. will even use a different approach
>> when
>> >> >> >> > persistence
>> >> >> >> > > > is
>> >> >> >> > > > > > > implemented.
>> >> >> >> > > > > > >
>> >> >> >> > > > > > > Regards,
>> >> >> >> > > > > > > --
>> >> >> >> > > > > > > Ilya Kasnacheev
>> >> >> >> > > > > > >
>> >> >> >> > > > > > >
>> >> >> >> > > > > > > пн, 28 июн. 2021 г. в 14:34, Atri Sharma
>> >> >> >> > > > > > > <at...@apache.org>:
>> >> >> >> > > > > > >
>> >> >> >> > > > > > > > Hello Again!
>> >> >> >> > > > > > > >
>> >> >> >> > > > > > > > I have been looking into the aforementioned and
>> >> >> >> > > > > > > > here
>> >> >> >> > > > > > > > are
>> >> >> my
>> >> >> >> > follow
>> >> >> >> > > > up
>> >> >> >> > > > > > > > thoughts:
>> >> >> >> > > > > > > >
>> >> >> >> > > > > > > > 1. Support persistence of Lucene indexes.
>> >> >> >> > > > > > > > 2.
>> https://issues.apache.org/jira/browse/IGNITE-12401
>> >> >> >> > > > > > > > (Needs
>> >> >> >> > > > fixing of
>> >> >> >> > > > > > > > moving partitions first)
>> >> >> >> > > > > > > > 3. Figure out how to return scores from nodes and
>> use
>> >> >> >> > > > > > > > them
>> >> >> >> > > > > > > > as
>> >> >> >> > sort
>> >> >> >> > > > > > > > parameters on the coordinator node
>> >> >> >> > > > > > > > (https://issues.apache.org/jira/browse/IGNITE-12291
>> )
>> >> >> >> > > > > > > >
>> >> >> >> > > > > > > > Please let me know if this looks ok to make text
>> >> >> >> > > > > > > > queries
>> >> >> >> > > > functional?
>> >> >> >> > > > > > > >
>> >> >> >> > > > > > > > Atri
>> >> >> >> > > > > > > >
>> >> >> >> > > > > > > > On Mon, Jun 21, 2021 at 2:49 PM Alexei Scherbakov
>> >> >> >> > > > > > > > <al...@gmail.com> wrote:
>> >> >> >> > > > > > > > >
>> >> >> >> > > > > > > > > Hi.
>> >> >> >> > > > > > > > >
>> >> >> >> > > > > > > > > One of the biggest issues with text queries is a
>> >> >> >> > > > > > > > > lack
>> >> >> >> > > > > > > > > of
>> >> >> >> > support
>> >> >> >> > > > for
>> >> >> >> > > > > > > > lucene
>> >> >> >> > > > > > > > > indices persistence, which makes this
>> functionality
>> >> >> >> > > > > > > > > useless
>> >> >> >> > if a
>> >> >> >> > > > > > > > > persistence is enabled.
>> >> >> >> > > > > > > > >
>> >> >> >> > > > > > > > > I would first take care of it.
>> >> >> >> > > > > > > > >
>> >> >> >> > > > > > > > > пн, 21 июн. 2021 г. в 12:16, Maksim Timonin <
>> >> >> >> > > > timonin.maxim@gmail.com
>> >> >> >> > > > > > >:
>> >> >> >> > > > > > > > >
>> >> >> >> > > > > > > > > > Hi, Atri!
>> >> >> >> > > > > > > > > >
>> >> >> >> > > > > > > > > > You're right, Actually there is a lack of
>> support
>> >> >> >> > > > > > > > > > for
>> >> >> >> > > > TextQueries.
>> >> >> >> > > > > > > For
>> >> >> >> > > > > > > > the
>> >> >> >> > > > > > > > > > last ticket I'm doing I see some obvious
>> >> >> >> > > > > > > > > > issues
>> >> >> >> > > > > > > > > > with
>> >> >> >> > > > > > > > > > them
>> >> >> >> > (no
>> >> >> >> > > > page
>> >> >> >> > > > > > > size
>> >> >> >> > > > > > > > > > support, for example). I'm glad that somebody
>> >> >> >> > > > > > > > > > wants
>> >> >> >> > > > > > > > > > to
>> >> >> >> > maintain
>> >> >> >> > > > > > this
>> >> >> >> > > > > > > > > > functionality. Thanks a lot!
>> >> >> >> > > > > > > > > >
>> >> >> >> > > > > > > > > > For the MergeSort algorithm there is already a
>> >> >> >> > > > > > > > > > patch
>> >> >> >> > > > > > > > > > for
>> >> >> >> > that
>> >> >> >> > > > [1].
>> >> >> >> > > > > > > It's
>> >> >> >> > > > > > > > > > currently on review. This patch introduces an
>> >> >> >> > > > > > > > > > abstract
>> >> >> >> > reducer
>> >> >> >> > > > for
>> >> >> >> > > > > > > > > > CacheQueries with 2 implementations
>> >> >> >> > > > > > > > > > (unordered,
>> >> >> >> > merge-sort).
>> >> >> >> > > > Then
>> >> >> >> > > > > > > > TextQuery
>> >> >> >> > > > > > > > > > leverages on MergeSort to order results from
>> >> >> >> > > > > > > > > > multiple
>> >> >> >> > nodes by
>> >> >> >> > > > > > score.
>> >> >> >> > > > > > > > This
>> >> >> >> > > > > > > > > > patch also fixes the pageSize issue, I've
>> >> >> >> > > > > > > > > > mentioned
>> >> >> >> > > > > > > > > > before.
>> >> >> >> > > > Could
>> >> >> >> > > > > > you
>> >> >> >> > > > > > > > > > please check if it fully matches your idea?
>> >> >> >> > > > > > > > > > Any
>> >> >> >> > > > > > > > > > issues
>> >> >> >> > > > > > > > > > or
>> >> >> >> > > > comments
>> >> >> >> > > > > > > are
>> >> >> >> > > > > > > > > > welcome.
>> >> >> >> > > > > > > > > >
>> >> >> >> > > > > > > > > > I've prepared this ticket, because I need the
>> >> >> MergeSort
>> >> >> >> > > > algorithm
>> >> >> >> > > > > > for
>> >> >> >> > > > > > > > the
>> >> >> >> > > > > > > > > > new type of queries I'm implementing
>> (IndexQuery,
>> >> >> >> > > > > > > > > > it
>> >> >> >> > > > > > > > > > should
>> >> >> >> > > > also
>> >> >> >> > > > > > > > provide
>> >> >> >> > > > > > > > > > ordered results over multiple nodes).
>> >> >> >> > > > > > > > > > Currently
>> >> >> >> > > > > > > > > > I'm
>> >> >> not
>> >> >> >> > > > planning to
>> >> >> >> > > > > > > go
>> >> >> >> > > > > > > > > > further with TextQuery, so if you're going to
>> >> >> >> > > > > > > > > > support
>> >> >> >> > > > > > > > > > this
>> >> >> >> > > > it'll
>> >> >> >> > > > > > be a
>> >> >> >> > > > > > > > great
>> >> >> >> > > > > > > > > > contribution, I think.
>> >> >> >> > > > > > > > > >
>> >> >> >> > > > > > > > > > [1]
>> >> >> https://issues.apache.org/jira/browse/IGNITE-14703
>> >> >> >> > > > > > > > > > [2] https://github.com/apache/ignite/pull/9081
>> >> >> >> > > > > > > > > >
>> >> >> >> > > > > > > > > >
>> >> >> >> > > > > > > > > > On Mon, Jun 21, 2021 at 11:11 AM Atri Sharma <
>> >> >> >> > atri@apache.org>
>> >> >> >> > > > > > > wrote:
>> >> >> >> > > > > > > > > >
>> >> >> >> > > > > > > > > > > Hi All,
>> >> >> >> > > > > > > > > > >
>> >> >> >> > > > > > > > > > > I have been looking into our text queries
>> >> >> >> > > > > > > > > > > support
>> >> >> and
>> >> >> >> > > > > > > > > > > see
>> >> >> >> > > > that it
>> >> >> >> > > > > > > has
>> >> >> >> > > > > > > > > > > limited community support.
>> >> >> >> > > > > > > > > > >
>> >> >> >> > > > > > > > > > > Therefore, I volunteer to be the maintainer
>> >> >> >> > > > > > > > > > > of
>> >> >> >> > > > > > > > > > > the
>> >> >> >> > module and
>> >> >> >> > > > > > work
>> >> >> >> > > > > > > on
>> >> >> >> > > > > > > > > > > enhancing it further.
>> >> >> >> > > > > > > > > > >
>> >> >> >> > > > > > > > > > > First goal would be to move to Lucene 8.x,
>> then
>> >> >> >> > > > > > > > > > > work
>> >> >> >> > > > > > > > > > > on
>> >> >> >> > > > sorted
>> >> >> >> > > > > > > reduce
>> >> >> >> > > > > > > > > > > - merge across nodes. Fundamentally, this is
>> >> >> >> > > > > > > > > > > doable
>> >> >> >> > > > > > > > > > > since
>> >> >> >> > > > Lucene
>> >> >> >> > > > > > > > ranks
>> >> >> >> > > > > > > > > > > documents according to their score, and
>> >> >> >> > > > > > > > > > > documents
>> >> >> are
>> >> >> >> > > > returned in
>> >> >> >> > > > > > > the
>> >> >> >> > > > > > > > > > > order of their score. Since the scoring
>> >> >> >> > > > > > > > > > > function
>> >> >> >> > > > > > > > > > > is
>> >> >> >> > > > homogeneous,
>> >> >> >> > > > > > > this
>> >> >> >> > > > > > > > > > > means that across nodes, we can compare
>> >> >> >> > > > > > > > > > > scores
>> >> >> >> > > > > > > > > > > and
>> >> >> >> > > > > > > > > > > merge
>> >> >> >> > > > sort.
>> >> >> >> > > > > > > > > > >
>> >> >> >> > > > > > > > > > > Please let me know if I can take this up.
>> >> >> >> > > > > > > > > > >
>> >> >> >> > > > > > > > > > > Atri
>> >> >> >> > > > > > > > > > >
>> >> >> >> > > > > > > > > > > --
>> >> >> >> > > > > > > > > > > Regards,
>> >> >> >> > > > > > > > > > >
>> >> >> >> > > > > > > > > > > Atri
>> >> >> >> > > > > > > > > > > Apache Concerted
>> >> >> >> > > > > > > > > > >
>> >> >> >> > > > > > > > > >
>> >> >> >> > > > > > > > >
>> >> >> >> > > > > > > > >
>> >> >> >> > > > > > > > > --
>> >> >> >> > > > > > > > >
>> >> >> >> > > > > > > > > Best regards,
>> >> >> >> > > > > > > > > Alexei Scherbakov
>> >> >> >> > > > > > > >
>> >> >> >> > > > > > > > --
>> >> >> >> > > > > > > > Regards,
>> >> >> >> > > > > > > >
>> >> >> >> > > > > > > > Atri
>> >> >> >> > > > > > > > Apache Concerted
>> >> >> >> > > > > > > >
>> >> >> >> > > > > > >
>> >> >> >> > > > > >
>> >> >> >> > > > >
>> >> >> >> > > > >
>> >> >> >> > > > > --
>> >> >> >> > > > > Best regards,
>> >> >> >> > > > > Andrey V. Mashenkov
>> >> >> >> > > >
>> >> >> >> > > > --
>> >> >> >> > > > Regards,
>> >> >> >> > > >
>> >> >> >> > > > Atri
>> >> >> >> > > > Apache Concerted
>> >> >> >> > > >
>> >> >> >> > >
>> >> >> >> > >
>> >> >> >> > > --
>> >> >> >> > > Best regards,
>> >> >> >> > > Andrey V. Mashenkov
>> >> >> >> >
>> >> >> >> > --
>> >> >> >> > Regards,
>> >> >> >> >
>> >> >> >> > Atri
>> >> >> >> > Apache Concerted
>> >> >> >> >
>> >> >> >>
>> >> >> >>
>> >> >> >> --
>> >> >> >> Best regards,
>> >> >> >> Andrey V. Mashenkov
>> >> >> >
>> >> >> > --
>> >> >> > Regards,
>> >> >> >
>> >> >> > Atri
>> >> >> > Apache Concerted
>> >> >> >
>> >> >>
>> >> >>
>> >> >> --
>> >> >>
>> >> >> Best regards,
>> >> >> Ivan Pavlukhin
>> >> >>
>> >> >
>> >>
>> >>
>> >> --
>> >>
>> >> Best regards,
>> >> Ivan Pavlukhin
>> >
>> > --
>> > Regards,
>> >
>> > Atri
>> > Apache Concerted
>> >
>>
>>
>> --
>>
>> Best regards,
>> Ivan Pavlukhin
>>
>
--
Best regards,
Ivan Pavlukhin
Re: Text Queries Support
Posted by Maximiliano Gazquez <ma...@gmail.com>.
Hello everyone!
I wanted to add this to the discussion.
I've found this project https://github.com/hawkore/ignite-hk which promises
to solve most of the issues that are being discussed here like pagination,
sorting and most important, persisting the lucene index.
It does stuff like this to create indexes:
CREATE INDEX PERSON_LUCENE_IDX ON "PUBLIC".PERSON(LUCENE)
FULLTEXT '{
''refresh_seconds'':''60'',
''directory_path'':'''',
''ram_buffer_mb'':''10'',
''max_cached_mb'':''-1'',
''partitioner'':''{"type":"token","partitions":10}'',
''optimizer_enabled'':''true'',
''optimizer_schedule'':''0 1 * * *'',
''version'':''0'',
''schema'':''{
"default_analyzer":"english",
"analyzers":{"my_custom_analyzer":{"type":"snowball","language":"Spanish","stopwords":"el,la,lo,loas,las,a,ante,bajo,cabe,con,contra"}},
"fields":{
"duration":{"type":"date_range","from":"start_date","to":"stop_date","validated":false,"pattern":"yyyy/MM/dd"},
"place":{"type":"geo_point","latitude":"latitude","longitude":"longitude"},
"date":{"type":"date","validated":true,"pattern":"yyyy/MM/dd"},
"number":{"type":"integer","validated":false,"boost":1.0},
"gender":{"type":"string","validated":true,"case_sensitive":true},
"bool":{"type":"boolean","validated":false},
"phrase":{"type":"text","validated":false,"analyzer":"my_custom_analyzer"},
"name":{"type":"string","validated":false,"case_sensitive":true},
"animal":{"type":"string","validated":false,"case_sensitive":true},
"age":{"type":"integer","validated":false,"boost":1.0},
"food":{"type":"string","validated":false,"case_sensitive":true}
}
}''
}';
And this to use that lucene index from inside SQL:
SELECT * FROM "test".user
WHERE lucene = '{ query : {
type : "boolean",
must : [{type : "wildcard", field : "name",
value : "J*"},
{type : "wildcard", field : "food",
value : "tu*"}]}}';
More examples here
https://github.com/hawkore/examples-apache-ignite-extensions/tree/master/examples-advanced-ignite-indexing
I don't have anything to do with that company but it would be great to know
how they implemented this stuff.
On Mon, Aug 9, 2021 at 3:00 AM Ivan Pavlukhin <vo...@gmail.com> wrote:
> Hi Atri,
>
> Sorry for a late answer.
>
> > I didn't quite understand. Are you proposing that Ignite should not have
> FTS capabilities?
>
> It seems an option to me. IMHO it is better to have no FTS instead of
> something like current Ignite TextQueries.
>
> 2021-08-03 12:45 GMT+03:00, Atri Sharma <at...@apache.org>:
> > Hi Ivan,
> >
> > I didn't quite understand. Are you proposing that Ignite should not
> > have FTS capabilities?
> >
> > Atri
> >
> > On Tue, Aug 3, 2021 at 2:57 PM Ivan Pavlukhin <vo...@gmail.com>
> wrote:
> >>
> >> Hi Atri,
> >>
> >> My main concern is non-maleficence. Every task has several solutions,
> >> e.g. straightforward ones:
> >> 1. Do not implement FTS.
> >> 2. Create own implementation.
> >>
> >> Some of the strongest ones live without FTS [1].
> >>
> >> [1] https://github.com/cockroachdb/cockroach/issues/7821
> >>
> >> 2021-08-02 11:33 GMT+03:00, Atri Sharma <at...@apache.org>:
> >> > Hi Ivan,
> >> >
> >> > Would you like to propose an alternative to Lucene?
> >> >
> >> > Atri
> >> >
> >> > On Mon, 2 Aug 2021, 13:48 Ivan Pavlukhin, <vo...@gmail.com>
> wrote:
> >> >
> >> >> Folks,
> >> >>
> >> >> Sorry if read the thread not thoroughly enough, but do we consider
> >> >> Lucene as obviously right choice? In my understanding Ignite history
> >> >> has shown clearly that "fastest feature implementation" is not
> usually
> >> >> the best. And one example of this are text queries. Are not we trying
> >> >> to do a same mistake again? FTS is a huge feature, I do not believe
> >> >> there is an easy win for it.
> >> >>
> >> >> 2021-07-27 19:18 GMT+03:00, Atri Sharma <at...@apache.org>:
> >> >> > Andrey,
> >> >> >
> >> >> >> Per-partition Lucene index looks simple to implement, but it may
> >> >> >> require
> >> >> >> per-partition SQL to make full-text search expressions work
> >> >> >> correctly
> >> >> >> within the SQL quiery.
> >> >> > I think that as long as we follow the map - reduce process that we
> >> >> > already do for other queries, we should be fine.
> >> >> >
> >> >> >> Per-partition SQL index may kill the performance. We already tried
> >> >> >> to
> >> >> >> do
> >> >> >> that in Ignite 2. However, QueryParallelism feature helps to speed
> >> >> >> up
> >> >> >> some
> >> >> >> data-intensive queries,
> >> >> >> but hits the performance in simple cases, and at some point (e.g.
> >> >> >> segments
> >> >> >> > number of CPU) the performance rapidly degrades with the
> >> >> >> > increasing
> >> >> >> number of segments.
> >> >> >
> >> >> > Yeah, that is always the case, but a global index will be a
> >> >> > nightmare
> >> >> > in terms of concurrency and pessimistic concurrency control will
> >> >> > anyways kill the benefits, coupled with the metadata requirements.
> >> >> > What were the specific issues with per partition index?
> >> >> >>
> >> >> >> AFAIK, Lucene widely used bitmap indices that are easy to merge.
> >> >> >> Maybe, the map-reduce technique underneath FTS expressions and
> some
> >> >> hacks
> >> >> >> will add a minimal overhead.
> >> >> >
> >> >> > Lucene uses many types of indices but the aspect here is that per
> >> >> > partition Lucene indices can return docIDs and we can merge them in
> >> >> > reduce phase. So we are abstracted out from specifics of the
> >> >> > internal
> >> >> > index being used to serve the query.
> >> >> >
> >> >> >>
> >> >> >> > As illustrated by Ilya, we can use Ignite's WAL records to
> >> >> >> > rebuild
> >> >> >> > Lucene indices. The important thing here is to not treat Lucene
> >> >> >> > indices as source of truth.
> >> >> >> To use WAL we either should relay Lucene files to our Page memory
> >> >> >> or
> >> >> >> be
> >> >> >> aware of Lucene files structure.
> >> >> >> The first looks tricky, as we should guarantee a contiguous
> address
> >> >> space
> >> >> >> in Page memory for reflecting Lucene file. Maybe separate managed
> >> >> >> memory
> >> >> >> segment with its own rules?
> >> >> >
> >> >> > Why not use Lucene's MMappedDirectory and map it to our storage
> >> >> > classes?
> >> >> >
> >> >> >>
> >> >> >> >> Transactions.
> >> >> >> >> * Will we support transactions?
> >> >> >> > Lucene has no concept of transactions.
> >> >> >> Yes, but we have.
> >> >> >> Lucene index may be non-transactional, but users never expect to
> >> >> >> see
> >> >> >> uncommited data.
> >> >> >> How does this connect with transactional SQL?
> >> >> > We could have the Lucene writes done as a part of transactions and
> >> >> > ack
> >> >> > back only when it succeeds/fails. WDYT?
> >> >> >>
> >> >> >> On Tue, Jul 27, 2021 at 1:36 PM Atri Sharma <at...@apache.org>
> >> >> >> wrote:
> >> >> >>
> >> >> >> > Sorry, I planned on creating a Wiki page for this, but it makes
> >> >> >> > more
> >> >> >> > sense to be replying here.
> >> >> >> >
> >> >> >> > > * How Lucene index can be split among the nodes?
> >> >> >> >
> >> >> >> > We can have partition level indices on each node.
> >> >> >> >
> >> >> >> > > * If we'll have a single index for all partitions on the
> >> >> >> > > particular
> >> >> >> > > node,
> >> >> >> > > then how index records will be aware of partitioning?
> >> >> >> >
> >> >> >> > Index records dont need to be aware of partitioning -- each
> >> >> >> > Lucene
> >> >> >> > index is independent.
> >> >> >> >
> >> >> >> > > This is important to filter out backup records from the
> results
> >> >> >> > > to
> >> >> >> > > avoid
> >> >> >> > > duplicates.
> >> >> >> >
> >> >> >> > We can merge documents from different nodes and remove
> duplicates
> >> >> >> > as
> >> >> >> > long as docIDs are globally unique.
> >> >> >> >
> >> >> >> > > * How results from several nodes can be merged on the Reduce
> >> >> >> > > stage?
> >> >> >> >
> >> >> >> > As long as documents have a globally unique docID, Lucene has
> >> >> >> > merge
> >> >> >> > functions that can merge results from multiple partial results.
> >> >> >> >
> >> >> >> > > * Does Lucene supports smth like JOIN operation or others that
> >> >> >> > > may
> >> >> >> > require
> >> >> >> > > data from another partition or index?
> >> >> >> >
> >> >> >> > As illustrated by Ilya, Block-Join works for us.
> >> >> >> >
> >> >> >> > > If so, then it likes to multistep query with merging results
> on
> >> >> >> > > intermediate stages and requires detailed investigation and
> >> >> >> > > design.
> >> >> >> > > It is ok if Ignite will have some limitations here, but we
> >> >> >> > > would
> >> >> like
> >> >> >> > > to
> >> >> >> > > know about them at the early stage.
> >> >> >> >
> >> >> >> > > * How effectively map Lucene files to the page memory? Is it
> >> >> >> > > even
> >> >> >> > possible?
> >> >> >> >
> >> >> >> > Lucene has PageDirectory implementations which allow storing
> >> >> >> > Lucene
> >> >> >> > indices on different kind of file structures. It has a
> >> >> >> > MMappedFileDirectory that we could use?
> >> >> >> >
> >> >> >> > > Otherwise, how to deal with potential OOM on large queries and
> >> >> memory
> >> >> >> > > capacity planning?
> >> >> >> >
> >> >> >> > We can use Lucene's MMapped directory.
> >> >> >> >
> >> >> >> > >
> >> >> >> > > Persistence.
> >> >> >> > > * How and what consistency guarantees could we have/expect?
> >> >> >> >
> >> >> >> > Lucene does not have WAL logs but is append only
> >> >> >> >
> >> >> >> > > Seems, we may not be able to write physical records for Lucene
> >> >> >> > > index
> >> >> >> > > to
> >> >> >> > our
> >> >> >> > > WAL. What can we do with this?
> >> >> >> >
> >> >> >> > As illustrated by Ilya, we can use Ignite's WAL records to
> >> >> >> > rebuild
> >> >> >> > Lucene indices. The important thing here is to not treat Lucene
> >> >> >> > indices as source of truth.
> >> >> >> > >
> >> >> >> > > Transactions.
> >> >> >> > > * Will we support transactions?
> >> >> >> > Lucene has no concept of transactions.
> >> >> >> >
> >> >> >> > > * Should Lucene be aware of Transaction and track mvcc (or
> >> >> >> > > whatever)
> >> >> >> > > versions for the records?
> >> >> >> > No
> >> >> >> > > * What will be consistency guarantees?
> >> >> >> > We can acknowledge writes back only after Lucene index is
> >> >> >> > updated.
> >> >> >> > >
> >> >> >> > > UX
> >> >> >> > > * How to add FullText search queries syntax into Calcite?
> >> >> >> > Postgres's FTS functions are a good reference.
> >> >> >> > > * AFAIK, the Lucene index has many properties for tuning. How
> >> >> >> > > will
> >> >> >> > > the
> >> >> >> > user
> >> >> >> > > configure the index?
> >> >> >> > Most of those properties can be cluster level and exposed as a
> >> >> >> > new
> >> >> >> > sub
> >> >> >> > config for ignite.
> >> >> >> > > * How and where to store the settings? What are cluster-wide
> >> >> >> > > and
> >> >> what
> >> >> >> > > a
> >> >> >> > > local to the particular node?
> >> >> >> > All can be cluster level.
> >> >> >> > > * Will be all the settings immutable? Can be they changed
> >> >> >> > > on-fly?
> >> >> >> > > after
> >> >> >> > > node/grid restart?
> >> >> >> > They should be applied post restart.
> >> >> >> >
> >> >> >> > > * Any limitations on query syntax?
> >> >> >> > It depends on how we model our queries for text search.
> >> >> >> >
> >> >> >> > >
> >> >> >> > > SQL
> >> >> >> > > * Will we support FullText search in SQL?
> >> >> >> > We need custom functions for it. See Postgres's FTS functions.
> >> >> >> > > * How to integrate Lucene index into Calcite? What is the cost
> >> >> model?
> >> >> >> > There cannot be any cost model since there are no paths for a
> >> >> >> > text
> >> >> >> > query. If we see a text query, we have to use Lucene index or
> >> >> >> > return
> >> >> >> > an error. In this way, we need to model text search as a set of
> >> >> >> > UDFs
> >> >> >> >
> >> >> >> > > Splitting rules? Traits?
> >> >> >> > Please see my reply above.
> >> >> >> > >
> >> >> >> > >
> >> >> >> > > With all of this, you can go with the IEP (or even some short
> >> >> >> > > summary)
> >> >> >> > and
> >> >> >> > > further POC and implementation.
> >> >> >> > > That's a big deal, so let's discuss what could be done here.
> >> >> >> > >
> >> >> >> > > On Fri, Jul 23, 2021 at 12:58 PM Atri Sharma <atri@apache.org
> >
> >> >> wrote:
> >> >> >> > >
> >> >> >> > > > I am actually happy to drive the feature for Ignite 3. FTS
> is
> >> >> >> > > > very
> >> >> >> > > > important for me and I think Ignite users will benefit from
> >> >> >> > > > it
> >> >> >> > > > greatly.
> >> >> >> > > >
> >> >> >> > > > If it makes sense to be focusing on Ignite 3 for this
> >> >> >> > > > capability,
> >> >> I
> >> >> >> > > > am
> >> >> >> > > > eager to contribute there and lead the development.
> >> >> >> > > >
> >> >> >> > > > Please share your thoughts.
> >> >> >> > > >
> >> >> >> > > > On Fri, Jul 23, 2021 at 3:21 PM Andrey Mashenkov
> >> >> >> > > > <an...@gmail.com> wrote:
> >> >> >> > > > >
> >> >> >> > > > > Hi Atri,
> >> >> >> > > > >
> >> >> >> > > > > All the Jira tickets we have on the Full-text search (FTS)
> >> >> >> > > > > thing
> >> >> >> > > > > are
> >> >> >> > > > > targeted to Ignite 2.
> >> >> >> > > > >
> >> >> >> > > > > AFAIK, we want, but we have NOT committed to FTS support
> in
> >> >> Ignite
> >> >> >> > > > > 3,
> >> >> >> > > > yet.
> >> >> >> > > > > By the way, we are getting requests for this thing from
> the
> >> >> >> > > > > user
> >> >> >> > side,
> >> >> >> > > > and
> >> >> >> > > > > definitely,
> >> >> >> > > > > FTS would be a valuable feature for Ignite.
> >> >> >> > > > >
> >> >> >> > > > > It will be great if the one wants to drive it, any help
> >> >> >> > > > > will
> >> >> >> > > > > be
> >> >> >> > > > appreciated.
> >> >> >> > > > >
> >> >> >> > > > >
> >> >> >> > > > > On Fri, Jul 23, 2021 at 12:12 PM Atri Sharma
> >> >> >> > > > > <at...@apache.org>
> >> >> >> > wrote:
> >> >> >> > > > >
> >> >> >> > > > > > Hello,
> >> >> >> > > > > >
> >> >> >> > > > > > An update, please. I am working through persistence of
> >> >> >> > > > > > Lucene
> >> >> >> > > > > > index
> >> >> >> > > > using
> >> >> >> > > > > > Ignite Dictionary, and will be asking some questions
> >> >> >> > > > > > soon.
> >> >> >> > > > > >
> >> >> >> > > > > > I had one doubt - - where does this change go? Ignite 3?
> >> >> >> > > > > >
> >> >> >> > > > > > Also, I know we want to build native support for text
> >> >> >> > > > > > searches
> >> >> >> > > > > > in
> >> >> >> > > > Ignite 3.
> >> >> >> > > > > > Is the work I am proposing here part of that, or will
> >> >> >> > > > > > that
> >> >> >> > > > > > be
> >> >> a
> >> >> >> > > > separate
> >> >> >> > > > > > effort?
> >> >> >> > > > > >
> >> >> >> > > > > > On Mon, 28 Jun 2021, 19:20 Ilya Kasnacheev, <
> >> >> >> > ilya.kasnacheev@gmail.com
> >> >> >> > > > >
> >> >> >> > > > > > wrote:
> >> >> >> > > > > >
> >> >> >> > > > > > > Hello!
> >> >> >> > > > > > >
> >> >> >> > > > > > > I think that number one is the most important one,
> then
> >> >> maybe
> >> >> >> > > > > > > it
> >> >> >> > > > will see
> >> >> >> > > > > > > more use and other deficiencies become more apparent,
> >> >> leading
> >> >> >> > > > > > > to
> >> >> >> > more
> >> >> >> > > > > > > tickets and visibility.
> >> >> >> > > > > > >
> >> >> >> > > > > > > Maybe 2. and 3. will even use a different approach
> when
> >> >> >> > persistence
> >> >> >> > > > is
> >> >> >> > > > > > > implemented.
> >> >> >> > > > > > >
> >> >> >> > > > > > > Regards,
> >> >> >> > > > > > > --
> >> >> >> > > > > > > Ilya Kasnacheev
> >> >> >> > > > > > >
> >> >> >> > > > > > >
> >> >> >> > > > > > > пн, 28 июн. 2021 г. в 14:34, Atri Sharma
> >> >> >> > > > > > > <at...@apache.org>:
> >> >> >> > > > > > >
> >> >> >> > > > > > > > Hello Again!
> >> >> >> > > > > > > >
> >> >> >> > > > > > > > I have been looking into the aforementioned and here
> >> >> >> > > > > > > > are
> >> >> my
> >> >> >> > follow
> >> >> >> > > > up
> >> >> >> > > > > > > > thoughts:
> >> >> >> > > > > > > >
> >> >> >> > > > > > > > 1. Support persistence of Lucene indexes.
> >> >> >> > > > > > > > 2.
> https://issues.apache.org/jira/browse/IGNITE-12401
> >> >> >> > > > > > > > (Needs
> >> >> >> > > > fixing of
> >> >> >> > > > > > > > moving partitions first)
> >> >> >> > > > > > > > 3. Figure out how to return scores from nodes and
> use
> >> >> >> > > > > > > > them
> >> >> >> > > > > > > > as
> >> >> >> > sort
> >> >> >> > > > > > > > parameters on the coordinator node
> >> >> >> > > > > > > > (https://issues.apache.org/jira/browse/IGNITE-12291
> )
> >> >> >> > > > > > > >
> >> >> >> > > > > > > > Please let me know if this looks ok to make text
> >> >> >> > > > > > > > queries
> >> >> >> > > > functional?
> >> >> >> > > > > > > >
> >> >> >> > > > > > > > Atri
> >> >> >> > > > > > > >
> >> >> >> > > > > > > > On Mon, Jun 21, 2021 at 2:49 PM Alexei Scherbakov
> >> >> >> > > > > > > > <al...@gmail.com> wrote:
> >> >> >> > > > > > > > >
> >> >> >> > > > > > > > > Hi.
> >> >> >> > > > > > > > >
> >> >> >> > > > > > > > > One of the biggest issues with text queries is a
> >> >> >> > > > > > > > > lack
> >> >> >> > > > > > > > > of
> >> >> >> > support
> >> >> >> > > > for
> >> >> >> > > > > > > > lucene
> >> >> >> > > > > > > > > indices persistence, which makes this
> functionality
> >> >> >> > > > > > > > > useless
> >> >> >> > if a
> >> >> >> > > > > > > > > persistence is enabled.
> >> >> >> > > > > > > > >
> >> >> >> > > > > > > > > I would first take care of it.
> >> >> >> > > > > > > > >
> >> >> >> > > > > > > > > пн, 21 июн. 2021 г. в 12:16, Maksim Timonin <
> >> >> >> > > > timonin.maxim@gmail.com
> >> >> >> > > > > > >:
> >> >> >> > > > > > > > >
> >> >> >> > > > > > > > > > Hi, Atri!
> >> >> >> > > > > > > > > >
> >> >> >> > > > > > > > > > You're right, Actually there is a lack of
> support
> >> >> >> > > > > > > > > > for
> >> >> >> > > > TextQueries.
> >> >> >> > > > > > > For
> >> >> >> > > > > > > > the
> >> >> >> > > > > > > > > > last ticket I'm doing I see some obvious issues
> >> >> >> > > > > > > > > > with
> >> >> >> > > > > > > > > > them
> >> >> >> > (no
> >> >> >> > > > page
> >> >> >> > > > > > > size
> >> >> >> > > > > > > > > > support, for example). I'm glad that somebody
> >> >> >> > > > > > > > > > wants
> >> >> >> > > > > > > > > > to
> >> >> >> > maintain
> >> >> >> > > > > > this
> >> >> >> > > > > > > > > > functionality. Thanks a lot!
> >> >> >> > > > > > > > > >
> >> >> >> > > > > > > > > > For the MergeSort algorithm there is already a
> >> >> >> > > > > > > > > > patch
> >> >> >> > > > > > > > > > for
> >> >> >> > that
> >> >> >> > > > [1].
> >> >> >> > > > > > > It's
> >> >> >> > > > > > > > > > currently on review. This patch introduces an
> >> >> >> > > > > > > > > > abstract
> >> >> >> > reducer
> >> >> >> > > > for
> >> >> >> > > > > > > > > > CacheQueries with 2 implementations (unordered,
> >> >> >> > merge-sort).
> >> >> >> > > > Then
> >> >> >> > > > > > > > TextQuery
> >> >> >> > > > > > > > > > leverages on MergeSort to order results from
> >> >> >> > > > > > > > > > multiple
> >> >> >> > nodes by
> >> >> >> > > > > > score.
> >> >> >> > > > > > > > This
> >> >> >> > > > > > > > > > patch also fixes the pageSize issue, I've
> >> >> >> > > > > > > > > > mentioned
> >> >> >> > > > > > > > > > before.
> >> >> >> > > > Could
> >> >> >> > > > > > you
> >> >> >> > > > > > > > > > please check if it fully matches your idea? Any
> >> >> >> > > > > > > > > > issues
> >> >> >> > > > > > > > > > or
> >> >> >> > > > comments
> >> >> >> > > > > > > are
> >> >> >> > > > > > > > > > welcome.
> >> >> >> > > > > > > > > >
> >> >> >> > > > > > > > > > I've prepared this ticket, because I need the
> >> >> MergeSort
> >> >> >> > > > algorithm
> >> >> >> > > > > > for
> >> >> >> > > > > > > > the
> >> >> >> > > > > > > > > > new type of queries I'm implementing
> (IndexQuery,
> >> >> >> > > > > > > > > > it
> >> >> >> > > > > > > > > > should
> >> >> >> > > > also
> >> >> >> > > > > > > > provide
> >> >> >> > > > > > > > > > ordered results over multiple nodes). Currently
> >> >> >> > > > > > > > > > I'm
> >> >> not
> >> >> >> > > > planning to
> >> >> >> > > > > > > go
> >> >> >> > > > > > > > > > further with TextQuery, so if you're going to
> >> >> >> > > > > > > > > > support
> >> >> >> > > > > > > > > > this
> >> >> >> > > > it'll
> >> >> >> > > > > > be a
> >> >> >> > > > > > > > great
> >> >> >> > > > > > > > > > contribution, I think.
> >> >> >> > > > > > > > > >
> >> >> >> > > > > > > > > > [1]
> >> >> https://issues.apache.org/jira/browse/IGNITE-14703
> >> >> >> > > > > > > > > > [2] https://github.com/apache/ignite/pull/9081
> >> >> >> > > > > > > > > >
> >> >> >> > > > > > > > > >
> >> >> >> > > > > > > > > > On Mon, Jun 21, 2021 at 11:11 AM Atri Sharma <
> >> >> >> > atri@apache.org>
> >> >> >> > > > > > > wrote:
> >> >> >> > > > > > > > > >
> >> >> >> > > > > > > > > > > Hi All,
> >> >> >> > > > > > > > > > >
> >> >> >> > > > > > > > > > > I have been looking into our text queries
> >> >> >> > > > > > > > > > > support
> >> >> and
> >> >> >> > > > > > > > > > > see
> >> >> >> > > > that it
> >> >> >> > > > > > > has
> >> >> >> > > > > > > > > > > limited community support.
> >> >> >> > > > > > > > > > >
> >> >> >> > > > > > > > > > > Therefore, I volunteer to be the maintainer of
> >> >> >> > > > > > > > > > > the
> >> >> >> > module and
> >> >> >> > > > > > work
> >> >> >> > > > > > > on
> >> >> >> > > > > > > > > > > enhancing it further.
> >> >> >> > > > > > > > > > >
> >> >> >> > > > > > > > > > > First goal would be to move to Lucene 8.x,
> then
> >> >> >> > > > > > > > > > > work
> >> >> >> > > > > > > > > > > on
> >> >> >> > > > sorted
> >> >> >> > > > > > > reduce
> >> >> >> > > > > > > > > > > - merge across nodes. Fundamentally, this is
> >> >> >> > > > > > > > > > > doable
> >> >> >> > > > > > > > > > > since
> >> >> >> > > > Lucene
> >> >> >> > > > > > > > ranks
> >> >> >> > > > > > > > > > > documents according to their score, and
> >> >> >> > > > > > > > > > > documents
> >> >> are
> >> >> >> > > > returned in
> >> >> >> > > > > > > the
> >> >> >> > > > > > > > > > > order of their score. Since the scoring
> >> >> >> > > > > > > > > > > function
> >> >> >> > > > > > > > > > > is
> >> >> >> > > > homogeneous,
> >> >> >> > > > > > > this
> >> >> >> > > > > > > > > > > means that across nodes, we can compare scores
> >> >> >> > > > > > > > > > > and
> >> >> >> > > > > > > > > > > merge
> >> >> >> > > > sort.
> >> >> >> > > > > > > > > > >
> >> >> >> > > > > > > > > > > Please let me know if I can take this up.
> >> >> >> > > > > > > > > > >
> >> >> >> > > > > > > > > > > Atri
> >> >> >> > > > > > > > > > >
> >> >> >> > > > > > > > > > > --
> >> >> >> > > > > > > > > > > Regards,
> >> >> >> > > > > > > > > > >
> >> >> >> > > > > > > > > > > Atri
> >> >> >> > > > > > > > > > > Apache Concerted
> >> >> >> > > > > > > > > > >
> >> >> >> > > > > > > > > >
> >> >> >> > > > > > > > >
> >> >> >> > > > > > > > >
> >> >> >> > > > > > > > > --
> >> >> >> > > > > > > > >
> >> >> >> > > > > > > > > Best regards,
> >> >> >> > > > > > > > > Alexei Scherbakov
> >> >> >> > > > > > > >
> >> >> >> > > > > > > > --
> >> >> >> > > > > > > > Regards,
> >> >> >> > > > > > > >
> >> >> >> > > > > > > > Atri
> >> >> >> > > > > > > > Apache Concerted
> >> >> >> > > > > > > >
> >> >> >> > > > > > >
> >> >> >> > > > > >
> >> >> >> > > > >
> >> >> >> > > > >
> >> >> >> > > > > --
> >> >> >> > > > > Best regards,
> >> >> >> > > > > Andrey V. Mashenkov
> >> >> >> > > >
> >> >> >> > > > --
> >> >> >> > > > Regards,
> >> >> >> > > >
> >> >> >> > > > Atri
> >> >> >> > > > Apache Concerted
> >> >> >> > > >
> >> >> >> > >
> >> >> >> > >
> >> >> >> > > --
> >> >> >> > > Best regards,
> >> >> >> > > Andrey V. Mashenkov
> >> >> >> >
> >> >> >> > --
> >> >> >> > Regards,
> >> >> >> >
> >> >> >> > Atri
> >> >> >> > Apache Concerted
> >> >> >> >
> >> >> >>
> >> >> >>
> >> >> >> --
> >> >> >> Best regards,
> >> >> >> Andrey V. Mashenkov
> >> >> >
> >> >> > --
> >> >> > Regards,
> >> >> >
> >> >> > Atri
> >> >> > Apache Concerted
> >> >> >
> >> >>
> >> >>
> >> >> --
> >> >>
> >> >> Best regards,
> >> >> Ivan Pavlukhin
> >> >>
> >> >
> >>
> >>
> >> --
> >>
> >> Best regards,
> >> Ivan Pavlukhin
> >
> > --
> > Regards,
> >
> > Atri
> > Apache Concerted
> >
>
>
> --
>
> Best regards,
> Ivan Pavlukhin
>
Re: Text Queries Support
Posted by Ivan Pavlukhin <vo...@gmail.com>.
Hi Atri,
Sorry for a late answer.
> I didn't quite understand. Are you proposing that Ignite should not have FTS capabilities?
It seems an option to me. IMHO it is better to have no FTS instead of
something like current Ignite TextQueries.
2021-08-03 12:45 GMT+03:00, Atri Sharma <at...@apache.org>:
> Hi Ivan,
>
> I didn't quite understand. Are you proposing that Ignite should not
> have FTS capabilities?
>
> Atri
>
> On Tue, Aug 3, 2021 at 2:57 PM Ivan Pavlukhin <vo...@gmail.com> wrote:
>>
>> Hi Atri,
>>
>> My main concern is non-maleficence. Every task has several solutions,
>> e.g. straightforward ones:
>> 1. Do not implement FTS.
>> 2. Create own implementation.
>>
>> Some of the strongest ones live without FTS [1].
>>
>> [1] https://github.com/cockroachdb/cockroach/issues/7821
>>
>> 2021-08-02 11:33 GMT+03:00, Atri Sharma <at...@apache.org>:
>> > Hi Ivan,
>> >
>> > Would you like to propose an alternative to Lucene?
>> >
>> > Atri
>> >
>> > On Mon, 2 Aug 2021, 13:48 Ivan Pavlukhin, <vo...@gmail.com> wrote:
>> >
>> >> Folks,
>> >>
>> >> Sorry if read the thread not thoroughly enough, but do we consider
>> >> Lucene as obviously right choice? In my understanding Ignite history
>> >> has shown clearly that "fastest feature implementation" is not usually
>> >> the best. And one example of this are text queries. Are not we trying
>> >> to do a same mistake again? FTS is a huge feature, I do not believe
>> >> there is an easy win for it.
>> >>
>> >> 2021-07-27 19:18 GMT+03:00, Atri Sharma <at...@apache.org>:
>> >> > Andrey,
>> >> >
>> >> >> Per-partition Lucene index looks simple to implement, but it may
>> >> >> require
>> >> >> per-partition SQL to make full-text search expressions work
>> >> >> correctly
>> >> >> within the SQL quiery.
>> >> > I think that as long as we follow the map - reduce process that we
>> >> > already do for other queries, we should be fine.
>> >> >
>> >> >> Per-partition SQL index may kill the performance. We already tried
>> >> >> to
>> >> >> do
>> >> >> that in Ignite 2. However, QueryParallelism feature helps to speed
>> >> >> up
>> >> >> some
>> >> >> data-intensive queries,
>> >> >> but hits the performance in simple cases, and at some point (e.g.
>> >> >> segments
>> >> >> > number of CPU) the performance rapidly degrades with the
>> >> >> > increasing
>> >> >> number of segments.
>> >> >
>> >> > Yeah, that is always the case, but a global index will be a
>> >> > nightmare
>> >> > in terms of concurrency and pessimistic concurrency control will
>> >> > anyways kill the benefits, coupled with the metadata requirements.
>> >> > What were the specific issues with per partition index?
>> >> >>
>> >> >> AFAIK, Lucene widely used bitmap indices that are easy to merge.
>> >> >> Maybe, the map-reduce technique underneath FTS expressions and some
>> >> hacks
>> >> >> will add a minimal overhead.
>> >> >
>> >> > Lucene uses many types of indices but the aspect here is that per
>> >> > partition Lucene indices can return docIDs and we can merge them in
>> >> > reduce phase. So we are abstracted out from specifics of the
>> >> > internal
>> >> > index being used to serve the query.
>> >> >
>> >> >>
>> >> >> > As illustrated by Ilya, we can use Ignite's WAL records to
>> >> >> > rebuild
>> >> >> > Lucene indices. The important thing here is to not treat Lucene
>> >> >> > indices as source of truth.
>> >> >> To use WAL we either should relay Lucene files to our Page memory
>> >> >> or
>> >> >> be
>> >> >> aware of Lucene files structure.
>> >> >> The first looks tricky, as we should guarantee a contiguous address
>> >> space
>> >> >> in Page memory for reflecting Lucene file. Maybe separate managed
>> >> >> memory
>> >> >> segment with its own rules?
>> >> >
>> >> > Why not use Lucene's MMappedDirectory and map it to our storage
>> >> > classes?
>> >> >
>> >> >>
>> >> >> >> Transactions.
>> >> >> >> * Will we support transactions?
>> >> >> > Lucene has no concept of transactions.
>> >> >> Yes, but we have.
>> >> >> Lucene index may be non-transactional, but users never expect to
>> >> >> see
>> >> >> uncommited data.
>> >> >> How does this connect with transactional SQL?
>> >> > We could have the Lucene writes done as a part of transactions and
>> >> > ack
>> >> > back only when it succeeds/fails. WDYT?
>> >> >>
>> >> >> On Tue, Jul 27, 2021 at 1:36 PM Atri Sharma <at...@apache.org>
>> >> >> wrote:
>> >> >>
>> >> >> > Sorry, I planned on creating a Wiki page for this, but it makes
>> >> >> > more
>> >> >> > sense to be replying here.
>> >> >> >
>> >> >> > > * How Lucene index can be split among the nodes?
>> >> >> >
>> >> >> > We can have partition level indices on each node.
>> >> >> >
>> >> >> > > * If we'll have a single index for all partitions on the
>> >> >> > > particular
>> >> >> > > node,
>> >> >> > > then how index records will be aware of partitioning?
>> >> >> >
>> >> >> > Index records dont need to be aware of partitioning -- each
>> >> >> > Lucene
>> >> >> > index is independent.
>> >> >> >
>> >> >> > > This is important to filter out backup records from the results
>> >> >> > > to
>> >> >> > > avoid
>> >> >> > > duplicates.
>> >> >> >
>> >> >> > We can merge documents from different nodes and remove duplicates
>> >> >> > as
>> >> >> > long as docIDs are globally unique.
>> >> >> >
>> >> >> > > * How results from several nodes can be merged on the Reduce
>> >> >> > > stage?
>> >> >> >
>> >> >> > As long as documents have a globally unique docID, Lucene has
>> >> >> > merge
>> >> >> > functions that can merge results from multiple partial results.
>> >> >> >
>> >> >> > > * Does Lucene supports smth like JOIN operation or others that
>> >> >> > > may
>> >> >> > require
>> >> >> > > data from another partition or index?
>> >> >> >
>> >> >> > As illustrated by Ilya, Block-Join works for us.
>> >> >> >
>> >> >> > > If so, then it likes to multistep query with merging results on
>> >> >> > > intermediate stages and requires detailed investigation and
>> >> >> > > design.
>> >> >> > > It is ok if Ignite will have some limitations here, but we
>> >> >> > > would
>> >> like
>> >> >> > > to
>> >> >> > > know about them at the early stage.
>> >> >> >
>> >> >> > > * How effectively map Lucene files to the page memory? Is it
>> >> >> > > even
>> >> >> > possible?
>> >> >> >
>> >> >> > Lucene has PageDirectory implementations which allow storing
>> >> >> > Lucene
>> >> >> > indices on different kind of file structures. It has a
>> >> >> > MMappedFileDirectory that we could use?
>> >> >> >
>> >> >> > > Otherwise, how to deal with potential OOM on large queries and
>> >> memory
>> >> >> > > capacity planning?
>> >> >> >
>> >> >> > We can use Lucene's MMapped directory.
>> >> >> >
>> >> >> > >
>> >> >> > > Persistence.
>> >> >> > > * How and what consistency guarantees could we have/expect?
>> >> >> >
>> >> >> > Lucene does not have WAL logs but is append only
>> >> >> >
>> >> >> > > Seems, we may not be able to write physical records for Lucene
>> >> >> > > index
>> >> >> > > to
>> >> >> > our
>> >> >> > > WAL. What can we do with this?
>> >> >> >
>> >> >> > As illustrated by Ilya, we can use Ignite's WAL records to
>> >> >> > rebuild
>> >> >> > Lucene indices. The important thing here is to not treat Lucene
>> >> >> > indices as source of truth.
>> >> >> > >
>> >> >> > > Transactions.
>> >> >> > > * Will we support transactions?
>> >> >> > Lucene has no concept of transactions.
>> >> >> >
>> >> >> > > * Should Lucene be aware of Transaction and track mvcc (or
>> >> >> > > whatever)
>> >> >> > > versions for the records?
>> >> >> > No
>> >> >> > > * What will be consistency guarantees?
>> >> >> > We can acknowledge writes back only after Lucene index is
>> >> >> > updated.
>> >> >> > >
>> >> >> > > UX
>> >> >> > > * How to add FullText search queries syntax into Calcite?
>> >> >> > Postgres's FTS functions are a good reference.
>> >> >> > > * AFAIK, the Lucene index has many properties for tuning. How
>> >> >> > > will
>> >> >> > > the
>> >> >> > user
>> >> >> > > configure the index?
>> >> >> > Most of those properties can be cluster level and exposed as a
>> >> >> > new
>> >> >> > sub
>> >> >> > config for ignite.
>> >> >> > > * How and where to store the settings? What are cluster-wide
>> >> >> > > and
>> >> what
>> >> >> > > a
>> >> >> > > local to the particular node?
>> >> >> > All can be cluster level.
>> >> >> > > * Will be all the settings immutable? Can be they changed
>> >> >> > > on-fly?
>> >> >> > > after
>> >> >> > > node/grid restart?
>> >> >> > They should be applied post restart.
>> >> >> >
>> >> >> > > * Any limitations on query syntax?
>> >> >> > It depends on how we model our queries for text search.
>> >> >> >
>> >> >> > >
>> >> >> > > SQL
>> >> >> > > * Will we support FullText search in SQL?
>> >> >> > We need custom functions for it. See Postgres's FTS functions.
>> >> >> > > * How to integrate Lucene index into Calcite? What is the cost
>> >> model?
>> >> >> > There cannot be any cost model since there are no paths for a
>> >> >> > text
>> >> >> > query. If we see a text query, we have to use Lucene index or
>> >> >> > return
>> >> >> > an error. In this way, we need to model text search as a set of
>> >> >> > UDFs
>> >> >> >
>> >> >> > > Splitting rules? Traits?
>> >> >> > Please see my reply above.
>> >> >> > >
>> >> >> > >
>> >> >> > > With all of this, you can go with the IEP (or even some short
>> >> >> > > summary)
>> >> >> > and
>> >> >> > > further POC and implementation.
>> >> >> > > That's a big deal, so let's discuss what could be done here.
>> >> >> > >
>> >> >> > > On Fri, Jul 23, 2021 at 12:58 PM Atri Sharma <at...@apache.org>
>> >> wrote:
>> >> >> > >
>> >> >> > > > I am actually happy to drive the feature for Ignite 3. FTS is
>> >> >> > > > very
>> >> >> > > > important for me and I think Ignite users will benefit from
>> >> >> > > > it
>> >> >> > > > greatly.
>> >> >> > > >
>> >> >> > > > If it makes sense to be focusing on Ignite 3 for this
>> >> >> > > > capability,
>> >> I
>> >> >> > > > am
>> >> >> > > > eager to contribute there and lead the development.
>> >> >> > > >
>> >> >> > > > Please share your thoughts.
>> >> >> > > >
>> >> >> > > > On Fri, Jul 23, 2021 at 3:21 PM Andrey Mashenkov
>> >> >> > > > <an...@gmail.com> wrote:
>> >> >> > > > >
>> >> >> > > > > Hi Atri,
>> >> >> > > > >
>> >> >> > > > > All the Jira tickets we have on the Full-text search (FTS)
>> >> >> > > > > thing
>> >> >> > > > > are
>> >> >> > > > > targeted to Ignite 2.
>> >> >> > > > >
>> >> >> > > > > AFAIK, we want, but we have NOT committed to FTS support in
>> >> Ignite
>> >> >> > > > > 3,
>> >> >> > > > yet.
>> >> >> > > > > By the way, we are getting requests for this thing from the
>> >> >> > > > > user
>> >> >> > side,
>> >> >> > > > and
>> >> >> > > > > definitely,
>> >> >> > > > > FTS would be a valuable feature for Ignite.
>> >> >> > > > >
>> >> >> > > > > It will be great if the one wants to drive it, any help
>> >> >> > > > > will
>> >> >> > > > > be
>> >> >> > > > appreciated.
>> >> >> > > > >
>> >> >> > > > >
>> >> >> > > > > On Fri, Jul 23, 2021 at 12:12 PM Atri Sharma
>> >> >> > > > > <at...@apache.org>
>> >> >> > wrote:
>> >> >> > > > >
>> >> >> > > > > > Hello,
>> >> >> > > > > >
>> >> >> > > > > > An update, please. I am working through persistence of
>> >> >> > > > > > Lucene
>> >> >> > > > > > index
>> >> >> > > > using
>> >> >> > > > > > Ignite Dictionary, and will be asking some questions
>> >> >> > > > > > soon.
>> >> >> > > > > >
>> >> >> > > > > > I had one doubt - - where does this change go? Ignite 3?
>> >> >> > > > > >
>> >> >> > > > > > Also, I know we want to build native support for text
>> >> >> > > > > > searches
>> >> >> > > > > > in
>> >> >> > > > Ignite 3.
>> >> >> > > > > > Is the work I am proposing here part of that, or will
>> >> >> > > > > > that
>> >> >> > > > > > be
>> >> a
>> >> >> > > > separate
>> >> >> > > > > > effort?
>> >> >> > > > > >
>> >> >> > > > > > On Mon, 28 Jun 2021, 19:20 Ilya Kasnacheev, <
>> >> >> > ilya.kasnacheev@gmail.com
>> >> >> > > > >
>> >> >> > > > > > wrote:
>> >> >> > > > > >
>> >> >> > > > > > > Hello!
>> >> >> > > > > > >
>> >> >> > > > > > > I think that number one is the most important one, then
>> >> maybe
>> >> >> > > > > > > it
>> >> >> > > > will see
>> >> >> > > > > > > more use and other deficiencies become more apparent,
>> >> leading
>> >> >> > > > > > > to
>> >> >> > more
>> >> >> > > > > > > tickets and visibility.
>> >> >> > > > > > >
>> >> >> > > > > > > Maybe 2. and 3. will even use a different approach when
>> >> >> > persistence
>> >> >> > > > is
>> >> >> > > > > > > implemented.
>> >> >> > > > > > >
>> >> >> > > > > > > Regards,
>> >> >> > > > > > > --
>> >> >> > > > > > > Ilya Kasnacheev
>> >> >> > > > > > >
>> >> >> > > > > > >
>> >> >> > > > > > > пн, 28 июн. 2021 г. в 14:34, Atri Sharma
>> >> >> > > > > > > <at...@apache.org>:
>> >> >> > > > > > >
>> >> >> > > > > > > > Hello Again!
>> >> >> > > > > > > >
>> >> >> > > > > > > > I have been looking into the aforementioned and here
>> >> >> > > > > > > > are
>> >> my
>> >> >> > follow
>> >> >> > > > up
>> >> >> > > > > > > > thoughts:
>> >> >> > > > > > > >
>> >> >> > > > > > > > 1. Support persistence of Lucene indexes.
>> >> >> > > > > > > > 2. https://issues.apache.org/jira/browse/IGNITE-12401
>> >> >> > > > > > > > (Needs
>> >> >> > > > fixing of
>> >> >> > > > > > > > moving partitions first)
>> >> >> > > > > > > > 3. Figure out how to return scores from nodes and use
>> >> >> > > > > > > > them
>> >> >> > > > > > > > as
>> >> >> > sort
>> >> >> > > > > > > > parameters on the coordinator node
>> >> >> > > > > > > > (https://issues.apache.org/jira/browse/IGNITE-12291)
>> >> >> > > > > > > >
>> >> >> > > > > > > > Please let me know if this looks ok to make text
>> >> >> > > > > > > > queries
>> >> >> > > > functional?
>> >> >> > > > > > > >
>> >> >> > > > > > > > Atri
>> >> >> > > > > > > >
>> >> >> > > > > > > > On Mon, Jun 21, 2021 at 2:49 PM Alexei Scherbakov
>> >> >> > > > > > > > <al...@gmail.com> wrote:
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > Hi.
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > One of the biggest issues with text queries is a
>> >> >> > > > > > > > > lack
>> >> >> > > > > > > > > of
>> >> >> > support
>> >> >> > > > for
>> >> >> > > > > > > > lucene
>> >> >> > > > > > > > > indices persistence, which makes this functionality
>> >> >> > > > > > > > > useless
>> >> >> > if a
>> >> >> > > > > > > > > persistence is enabled.
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > I would first take care of it.
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > пн, 21 июн. 2021 г. в 12:16, Maksim Timonin <
>> >> >> > > > timonin.maxim@gmail.com
>> >> >> > > > > > >:
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > > Hi, Atri!
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > > You're right, Actually there is a lack of support
>> >> >> > > > > > > > > > for
>> >> >> > > > TextQueries.
>> >> >> > > > > > > For
>> >> >> > > > > > > > the
>> >> >> > > > > > > > > > last ticket I'm doing I see some obvious issues
>> >> >> > > > > > > > > > with
>> >> >> > > > > > > > > > them
>> >> >> > (no
>> >> >> > > > page
>> >> >> > > > > > > size
>> >> >> > > > > > > > > > support, for example). I'm glad that somebody
>> >> >> > > > > > > > > > wants
>> >> >> > > > > > > > > > to
>> >> >> > maintain
>> >> >> > > > > > this
>> >> >> > > > > > > > > > functionality. Thanks a lot!
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > > For the MergeSort algorithm there is already a
>> >> >> > > > > > > > > > patch
>> >> >> > > > > > > > > > for
>> >> >> > that
>> >> >> > > > [1].
>> >> >> > > > > > > It's
>> >> >> > > > > > > > > > currently on review. This patch introduces an
>> >> >> > > > > > > > > > abstract
>> >> >> > reducer
>> >> >> > > > for
>> >> >> > > > > > > > > > CacheQueries with 2 implementations (unordered,
>> >> >> > merge-sort).
>> >> >> > > > Then
>> >> >> > > > > > > > TextQuery
>> >> >> > > > > > > > > > leverages on MergeSort to order results from
>> >> >> > > > > > > > > > multiple
>> >> >> > nodes by
>> >> >> > > > > > score.
>> >> >> > > > > > > > This
>> >> >> > > > > > > > > > patch also fixes the pageSize issue, I've
>> >> >> > > > > > > > > > mentioned
>> >> >> > > > > > > > > > before.
>> >> >> > > > Could
>> >> >> > > > > > you
>> >> >> > > > > > > > > > please check if it fully matches your idea? Any
>> >> >> > > > > > > > > > issues
>> >> >> > > > > > > > > > or
>> >> >> > > > comments
>> >> >> > > > > > > are
>> >> >> > > > > > > > > > welcome.
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > > I've prepared this ticket, because I need the
>> >> MergeSort
>> >> >> > > > algorithm
>> >> >> > > > > > for
>> >> >> > > > > > > > the
>> >> >> > > > > > > > > > new type of queries I'm implementing (IndexQuery,
>> >> >> > > > > > > > > > it
>> >> >> > > > > > > > > > should
>> >> >> > > > also
>> >> >> > > > > > > > provide
>> >> >> > > > > > > > > > ordered results over multiple nodes). Currently
>> >> >> > > > > > > > > > I'm
>> >> not
>> >> >> > > > planning to
>> >> >> > > > > > > go
>> >> >> > > > > > > > > > further with TextQuery, so if you're going to
>> >> >> > > > > > > > > > support
>> >> >> > > > > > > > > > this
>> >> >> > > > it'll
>> >> >> > > > > > be a
>> >> >> > > > > > > > great
>> >> >> > > > > > > > > > contribution, I think.
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > > [1]
>> >> https://issues.apache.org/jira/browse/IGNITE-14703
>> >> >> > > > > > > > > > [2] https://github.com/apache/ignite/pull/9081
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > > On Mon, Jun 21, 2021 at 11:11 AM Atri Sharma <
>> >> >> > atri@apache.org>
>> >> >> > > > > > > wrote:
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > > > Hi All,
>> >> >> > > > > > > > > > >
>> >> >> > > > > > > > > > > I have been looking into our text queries
>> >> >> > > > > > > > > > > support
>> >> and
>> >> >> > > > > > > > > > > see
>> >> >> > > > that it
>> >> >> > > > > > > has
>> >> >> > > > > > > > > > > limited community support.
>> >> >> > > > > > > > > > >
>> >> >> > > > > > > > > > > Therefore, I volunteer to be the maintainer of
>> >> >> > > > > > > > > > > the
>> >> >> > module and
>> >> >> > > > > > work
>> >> >> > > > > > > on
>> >> >> > > > > > > > > > > enhancing it further.
>> >> >> > > > > > > > > > >
>> >> >> > > > > > > > > > > First goal would be to move to Lucene 8.x, then
>> >> >> > > > > > > > > > > work
>> >> >> > > > > > > > > > > on
>> >> >> > > > sorted
>> >> >> > > > > > > reduce
>> >> >> > > > > > > > > > > - merge across nodes. Fundamentally, this is
>> >> >> > > > > > > > > > > doable
>> >> >> > > > > > > > > > > since
>> >> >> > > > Lucene
>> >> >> > > > > > > > ranks
>> >> >> > > > > > > > > > > documents according to their score, and
>> >> >> > > > > > > > > > > documents
>> >> are
>> >> >> > > > returned in
>> >> >> > > > > > > the
>> >> >> > > > > > > > > > > order of their score. Since the scoring
>> >> >> > > > > > > > > > > function
>> >> >> > > > > > > > > > > is
>> >> >> > > > homogeneous,
>> >> >> > > > > > > this
>> >> >> > > > > > > > > > > means that across nodes, we can compare scores
>> >> >> > > > > > > > > > > and
>> >> >> > > > > > > > > > > merge
>> >> >> > > > sort.
>> >> >> > > > > > > > > > >
>> >> >> > > > > > > > > > > Please let me know if I can take this up.
>> >> >> > > > > > > > > > >
>> >> >> > > > > > > > > > > Atri
>> >> >> > > > > > > > > > >
>> >> >> > > > > > > > > > > --
>> >> >> > > > > > > > > > > Regards,
>> >> >> > > > > > > > > > >
>> >> >> > > > > > > > > > > Atri
>> >> >> > > > > > > > > > > Apache Concerted
>> >> >> > > > > > > > > > >
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > >
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > --
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > Best regards,
>> >> >> > > > > > > > > Alexei Scherbakov
>> >> >> > > > > > > >
>> >> >> > > > > > > > --
>> >> >> > > > > > > > Regards,
>> >> >> > > > > > > >
>> >> >> > > > > > > > Atri
>> >> >> > > > > > > > Apache Concerted
>> >> >> > > > > > > >
>> >> >> > > > > > >
>> >> >> > > > > >
>> >> >> > > > >
>> >> >> > > > >
>> >> >> > > > > --
>> >> >> > > > > Best regards,
>> >> >> > > > > Andrey V. Mashenkov
>> >> >> > > >
>> >> >> > > > --
>> >> >> > > > Regards,
>> >> >> > > >
>> >> >> > > > Atri
>> >> >> > > > Apache Concerted
>> >> >> > > >
>> >> >> > >
>> >> >> > >
>> >> >> > > --
>> >> >> > > Best regards,
>> >> >> > > Andrey V. Mashenkov
>> >> >> >
>> >> >> > --
>> >> >> > Regards,
>> >> >> >
>> >> >> > Atri
>> >> >> > Apache Concerted
>> >> >> >
>> >> >>
>> >> >>
>> >> >> --
>> >> >> Best regards,
>> >> >> Andrey V. Mashenkov
>> >> >
>> >> > --
>> >> > Regards,
>> >> >
>> >> > Atri
>> >> > Apache Concerted
>> >> >
>> >>
>> >>
>> >> --
>> >>
>> >> Best regards,
>> >> Ivan Pavlukhin
>> >>
>> >
>>
>>
>> --
>>
>> Best regards,
>> Ivan Pavlukhin
>
> --
> Regards,
>
> Atri
> Apache Concerted
>
--
Best regards,
Ivan Pavlukhin
Re: Text Queries Support
Posted by Atri Sharma <at...@apache.org>.
Hi Ivan,
I didn't quite understand. Are you proposing that Ignite should not
have FTS capabilities?
Atri
On Tue, Aug 3, 2021 at 2:57 PM Ivan Pavlukhin <vo...@gmail.com> wrote:
>
> Hi Atri,
>
> My main concern is non-maleficence. Every task has several solutions,
> e.g. straightforward ones:
> 1. Do not implement FTS.
> 2. Create own implementation.
>
> Some of the strongest ones live without FTS [1].
>
> [1] https://github.com/cockroachdb/cockroach/issues/7821
>
> 2021-08-02 11:33 GMT+03:00, Atri Sharma <at...@apache.org>:
> > Hi Ivan,
> >
> > Would you like to propose an alternative to Lucene?
> >
> > Atri
> >
> > On Mon, 2 Aug 2021, 13:48 Ivan Pavlukhin, <vo...@gmail.com> wrote:
> >
> >> Folks,
> >>
> >> Sorry if read the thread not thoroughly enough, but do we consider
> >> Lucene as obviously right choice? In my understanding Ignite history
> >> has shown clearly that "fastest feature implementation" is not usually
> >> the best. And one example of this are text queries. Are not we trying
> >> to do a same mistake again? FTS is a huge feature, I do not believe
> >> there is an easy win for it.
> >>
> >> 2021-07-27 19:18 GMT+03:00, Atri Sharma <at...@apache.org>:
> >> > Andrey,
> >> >
> >> >> Per-partition Lucene index looks simple to implement, but it may
> >> >> require
> >> >> per-partition SQL to make full-text search expressions work correctly
> >> >> within the SQL quiery.
> >> > I think that as long as we follow the map - reduce process that we
> >> > already do for other queries, we should be fine.
> >> >
> >> >> Per-partition SQL index may kill the performance. We already tried to
> >> >> do
> >> >> that in Ignite 2. However, QueryParallelism feature helps to speed up
> >> >> some
> >> >> data-intensive queries,
> >> >> but hits the performance in simple cases, and at some point (e.g.
> >> >> segments
> >> >> > number of CPU) the performance rapidly degrades with the increasing
> >> >> number of segments.
> >> >
> >> > Yeah, that is always the case, but a global index will be a nightmare
> >> > in terms of concurrency and pessimistic concurrency control will
> >> > anyways kill the benefits, coupled with the metadata requirements.
> >> > What were the specific issues with per partition index?
> >> >>
> >> >> AFAIK, Lucene widely used bitmap indices that are easy to merge.
> >> >> Maybe, the map-reduce technique underneath FTS expressions and some
> >> hacks
> >> >> will add a minimal overhead.
> >> >
> >> > Lucene uses many types of indices but the aspect here is that per
> >> > partition Lucene indices can return docIDs and we can merge them in
> >> > reduce phase. So we are abstracted out from specifics of the internal
> >> > index being used to serve the query.
> >> >
> >> >>
> >> >> > As illustrated by Ilya, we can use Ignite's WAL records to rebuild
> >> >> > Lucene indices. The important thing here is to not treat Lucene
> >> >> > indices as source of truth.
> >> >> To use WAL we either should relay Lucene files to our Page memory or
> >> >> be
> >> >> aware of Lucene files structure.
> >> >> The first looks tricky, as we should guarantee a contiguous address
> >> space
> >> >> in Page memory for reflecting Lucene file. Maybe separate managed
> >> >> memory
> >> >> segment with its own rules?
> >> >
> >> > Why not use Lucene's MMappedDirectory and map it to our storage
> >> > classes?
> >> >
> >> >>
> >> >> >> Transactions.
> >> >> >> * Will we support transactions?
> >> >> > Lucene has no concept of transactions.
> >> >> Yes, but we have.
> >> >> Lucene index may be non-transactional, but users never expect to see
> >> >> uncommited data.
> >> >> How does this connect with transactional SQL?
> >> > We could have the Lucene writes done as a part of transactions and ack
> >> > back only when it succeeds/fails. WDYT?
> >> >>
> >> >> On Tue, Jul 27, 2021 at 1:36 PM Atri Sharma <at...@apache.org> wrote:
> >> >>
> >> >> > Sorry, I planned on creating a Wiki page for this, but it makes more
> >> >> > sense to be replying here.
> >> >> >
> >> >> > > * How Lucene index can be split among the nodes?
> >> >> >
> >> >> > We can have partition level indices on each node.
> >> >> >
> >> >> > > * If we'll have a single index for all partitions on the
> >> >> > > particular
> >> >> > > node,
> >> >> > > then how index records will be aware of partitioning?
> >> >> >
> >> >> > Index records dont need to be aware of partitioning -- each Lucene
> >> >> > index is independent.
> >> >> >
> >> >> > > This is important to filter out backup records from the results to
> >> >> > > avoid
> >> >> > > duplicates.
> >> >> >
> >> >> > We can merge documents from different nodes and remove duplicates as
> >> >> > long as docIDs are globally unique.
> >> >> >
> >> >> > > * How results from several nodes can be merged on the Reduce
> >> >> > > stage?
> >> >> >
> >> >> > As long as documents have a globally unique docID, Lucene has merge
> >> >> > functions that can merge results from multiple partial results.
> >> >> >
> >> >> > > * Does Lucene supports smth like JOIN operation or others that may
> >> >> > require
> >> >> > > data from another partition or index?
> >> >> >
> >> >> > As illustrated by Ilya, Block-Join works for us.
> >> >> >
> >> >> > > If so, then it likes to multistep query with merging results on
> >> >> > > intermediate stages and requires detailed investigation and
> >> >> > > design.
> >> >> > > It is ok if Ignite will have some limitations here, but we would
> >> like
> >> >> > > to
> >> >> > > know about them at the early stage.
> >> >> >
> >> >> > > * How effectively map Lucene files to the page memory? Is it even
> >> >> > possible?
> >> >> >
> >> >> > Lucene has PageDirectory implementations which allow storing Lucene
> >> >> > indices on different kind of file structures. It has a
> >> >> > MMappedFileDirectory that we could use?
> >> >> >
> >> >> > > Otherwise, how to deal with potential OOM on large queries and
> >> memory
> >> >> > > capacity planning?
> >> >> >
> >> >> > We can use Lucene's MMapped directory.
> >> >> >
> >> >> > >
> >> >> > > Persistence.
> >> >> > > * How and what consistency guarantees could we have/expect?
> >> >> >
> >> >> > Lucene does not have WAL logs but is append only
> >> >> >
> >> >> > > Seems, we may not be able to write physical records for Lucene
> >> >> > > index
> >> >> > > to
> >> >> > our
> >> >> > > WAL. What can we do with this?
> >> >> >
> >> >> > As illustrated by Ilya, we can use Ignite's WAL records to rebuild
> >> >> > Lucene indices. The important thing here is to not treat Lucene
> >> >> > indices as source of truth.
> >> >> > >
> >> >> > > Transactions.
> >> >> > > * Will we support transactions?
> >> >> > Lucene has no concept of transactions.
> >> >> >
> >> >> > > * Should Lucene be aware of Transaction and track mvcc (or
> >> >> > > whatever)
> >> >> > > versions for the records?
> >> >> > No
> >> >> > > * What will be consistency guarantees?
> >> >> > We can acknowledge writes back only after Lucene index is updated.
> >> >> > >
> >> >> > > UX
> >> >> > > * How to add FullText search queries syntax into Calcite?
> >> >> > Postgres's FTS functions are a good reference.
> >> >> > > * AFAIK, the Lucene index has many properties for tuning. How will
> >> >> > > the
> >> >> > user
> >> >> > > configure the index?
> >> >> > Most of those properties can be cluster level and exposed as a new
> >> >> > sub
> >> >> > config for ignite.
> >> >> > > * How and where to store the settings? What are cluster-wide and
> >> what
> >> >> > > a
> >> >> > > local to the particular node?
> >> >> > All can be cluster level.
> >> >> > > * Will be all the settings immutable? Can be they changed on-fly?
> >> >> > > after
> >> >> > > node/grid restart?
> >> >> > They should be applied post restart.
> >> >> >
> >> >> > > * Any limitations on query syntax?
> >> >> > It depends on how we model our queries for text search.
> >> >> >
> >> >> > >
> >> >> > > SQL
> >> >> > > * Will we support FullText search in SQL?
> >> >> > We need custom functions for it. See Postgres's FTS functions.
> >> >> > > * How to integrate Lucene index into Calcite? What is the cost
> >> model?
> >> >> > There cannot be any cost model since there are no paths for a text
> >> >> > query. If we see a text query, we have to use Lucene index or return
> >> >> > an error. In this way, we need to model text search as a set of UDFs
> >> >> >
> >> >> > > Splitting rules? Traits?
> >> >> > Please see my reply above.
> >> >> > >
> >> >> > >
> >> >> > > With all of this, you can go with the IEP (or even some short
> >> >> > > summary)
> >> >> > and
> >> >> > > further POC and implementation.
> >> >> > > That's a big deal, so let's discuss what could be done here.
> >> >> > >
> >> >> > > On Fri, Jul 23, 2021 at 12:58 PM Atri Sharma <at...@apache.org>
> >> wrote:
> >> >> > >
> >> >> > > > I am actually happy to drive the feature for Ignite 3. FTS is
> >> >> > > > very
> >> >> > > > important for me and I think Ignite users will benefit from it
> >> >> > > > greatly.
> >> >> > > >
> >> >> > > > If it makes sense to be focusing on Ignite 3 for this
> >> >> > > > capability,
> >> I
> >> >> > > > am
> >> >> > > > eager to contribute there and lead the development.
> >> >> > > >
> >> >> > > > Please share your thoughts.
> >> >> > > >
> >> >> > > > On Fri, Jul 23, 2021 at 3:21 PM Andrey Mashenkov
> >> >> > > > <an...@gmail.com> wrote:
> >> >> > > > >
> >> >> > > > > Hi Atri,
> >> >> > > > >
> >> >> > > > > All the Jira tickets we have on the Full-text search (FTS)
> >> >> > > > > thing
> >> >> > > > > are
> >> >> > > > > targeted to Ignite 2.
> >> >> > > > >
> >> >> > > > > AFAIK, we want, but we have NOT committed to FTS support in
> >> Ignite
> >> >> > > > > 3,
> >> >> > > > yet.
> >> >> > > > > By the way, we are getting requests for this thing from the
> >> >> > > > > user
> >> >> > side,
> >> >> > > > and
> >> >> > > > > definitely,
> >> >> > > > > FTS would be a valuable feature for Ignite.
> >> >> > > > >
> >> >> > > > > It will be great if the one wants to drive it, any help will
> >> >> > > > > be
> >> >> > > > appreciated.
> >> >> > > > >
> >> >> > > > >
> >> >> > > > > On Fri, Jul 23, 2021 at 12:12 PM Atri Sharma <at...@apache.org>
> >> >> > wrote:
> >> >> > > > >
> >> >> > > > > > Hello,
> >> >> > > > > >
> >> >> > > > > > An update, please. I am working through persistence of
> >> >> > > > > > Lucene
> >> >> > > > > > index
> >> >> > > > using
> >> >> > > > > > Ignite Dictionary, and will be asking some questions soon.
> >> >> > > > > >
> >> >> > > > > > I had one doubt - - where does this change go? Ignite 3?
> >> >> > > > > >
> >> >> > > > > > Also, I know we want to build native support for text
> >> >> > > > > > searches
> >> >> > > > > > in
> >> >> > > > Ignite 3.
> >> >> > > > > > Is the work I am proposing here part of that, or will that
> >> >> > > > > > be
> >> a
> >> >> > > > separate
> >> >> > > > > > effort?
> >> >> > > > > >
> >> >> > > > > > On Mon, 28 Jun 2021, 19:20 Ilya Kasnacheev, <
> >> >> > ilya.kasnacheev@gmail.com
> >> >> > > > >
> >> >> > > > > > wrote:
> >> >> > > > > >
> >> >> > > > > > > Hello!
> >> >> > > > > > >
> >> >> > > > > > > I think that number one is the most important one, then
> >> maybe
> >> >> > > > > > > it
> >> >> > > > will see
> >> >> > > > > > > more use and other deficiencies become more apparent,
> >> leading
> >> >> > > > > > > to
> >> >> > more
> >> >> > > > > > > tickets and visibility.
> >> >> > > > > > >
> >> >> > > > > > > Maybe 2. and 3. will even use a different approach when
> >> >> > persistence
> >> >> > > > is
> >> >> > > > > > > implemented.
> >> >> > > > > > >
> >> >> > > > > > > Regards,
> >> >> > > > > > > --
> >> >> > > > > > > Ilya Kasnacheev
> >> >> > > > > > >
> >> >> > > > > > >
> >> >> > > > > > > пн, 28 июн. 2021 г. в 14:34, Atri Sharma
> >> >> > > > > > > <at...@apache.org>:
> >> >> > > > > > >
> >> >> > > > > > > > Hello Again!
> >> >> > > > > > > >
> >> >> > > > > > > > I have been looking into the aforementioned and here are
> >> my
> >> >> > follow
> >> >> > > > up
> >> >> > > > > > > > thoughts:
> >> >> > > > > > > >
> >> >> > > > > > > > 1. Support persistence of Lucene indexes.
> >> >> > > > > > > > 2. https://issues.apache.org/jira/browse/IGNITE-12401
> >> >> > > > > > > > (Needs
> >> >> > > > fixing of
> >> >> > > > > > > > moving partitions first)
> >> >> > > > > > > > 3. Figure out how to return scores from nodes and use
> >> >> > > > > > > > them
> >> >> > > > > > > > as
> >> >> > sort
> >> >> > > > > > > > parameters on the coordinator node
> >> >> > > > > > > > (https://issues.apache.org/jira/browse/IGNITE-12291)
> >> >> > > > > > > >
> >> >> > > > > > > > Please let me know if this looks ok to make text queries
> >> >> > > > functional?
> >> >> > > > > > > >
> >> >> > > > > > > > Atri
> >> >> > > > > > > >
> >> >> > > > > > > > On Mon, Jun 21, 2021 at 2:49 PM Alexei Scherbakov
> >> >> > > > > > > > <al...@gmail.com> wrote:
> >> >> > > > > > > > >
> >> >> > > > > > > > > Hi.
> >> >> > > > > > > > >
> >> >> > > > > > > > > One of the biggest issues with text queries is a lack
> >> >> > > > > > > > > of
> >> >> > support
> >> >> > > > for
> >> >> > > > > > > > lucene
> >> >> > > > > > > > > indices persistence, which makes this functionality
> >> >> > > > > > > > > useless
> >> >> > if a
> >> >> > > > > > > > > persistence is enabled.
> >> >> > > > > > > > >
> >> >> > > > > > > > > I would first take care of it.
> >> >> > > > > > > > >
> >> >> > > > > > > > > пн, 21 июн. 2021 г. в 12:16, Maksim Timonin <
> >> >> > > > timonin.maxim@gmail.com
> >> >> > > > > > >:
> >> >> > > > > > > > >
> >> >> > > > > > > > > > Hi, Atri!
> >> >> > > > > > > > > >
> >> >> > > > > > > > > > You're right, Actually there is a lack of support
> >> >> > > > > > > > > > for
> >> >> > > > TextQueries.
> >> >> > > > > > > For
> >> >> > > > > > > > the
> >> >> > > > > > > > > > last ticket I'm doing I see some obvious issues with
> >> >> > > > > > > > > > them
> >> >> > (no
> >> >> > > > page
> >> >> > > > > > > size
> >> >> > > > > > > > > > support, for example). I'm glad that somebody wants
> >> >> > > > > > > > > > to
> >> >> > maintain
> >> >> > > > > > this
> >> >> > > > > > > > > > functionality. Thanks a lot!
> >> >> > > > > > > > > >
> >> >> > > > > > > > > > For the MergeSort algorithm there is already a patch
> >> >> > > > > > > > > > for
> >> >> > that
> >> >> > > > [1].
> >> >> > > > > > > It's
> >> >> > > > > > > > > > currently on review. This patch introduces an
> >> >> > > > > > > > > > abstract
> >> >> > reducer
> >> >> > > > for
> >> >> > > > > > > > > > CacheQueries with 2 implementations (unordered,
> >> >> > merge-sort).
> >> >> > > > Then
> >> >> > > > > > > > TextQuery
> >> >> > > > > > > > > > leverages on MergeSort to order results from
> >> >> > > > > > > > > > multiple
> >> >> > nodes by
> >> >> > > > > > score.
> >> >> > > > > > > > This
> >> >> > > > > > > > > > patch also fixes the pageSize issue, I've mentioned
> >> >> > > > > > > > > > before.
> >> >> > > > Could
> >> >> > > > > > you
> >> >> > > > > > > > > > please check if it fully matches your idea? Any
> >> >> > > > > > > > > > issues
> >> >> > > > > > > > > > or
> >> >> > > > comments
> >> >> > > > > > > are
> >> >> > > > > > > > > > welcome.
> >> >> > > > > > > > > >
> >> >> > > > > > > > > > I've prepared this ticket, because I need the
> >> MergeSort
> >> >> > > > algorithm
> >> >> > > > > > for
> >> >> > > > > > > > the
> >> >> > > > > > > > > > new type of queries I'm implementing (IndexQuery, it
> >> >> > > > > > > > > > should
> >> >> > > > also
> >> >> > > > > > > > provide
> >> >> > > > > > > > > > ordered results over multiple nodes). Currently I'm
> >> not
> >> >> > > > planning to
> >> >> > > > > > > go
> >> >> > > > > > > > > > further with TextQuery, so if you're going to
> >> >> > > > > > > > > > support
> >> >> > > > > > > > > > this
> >> >> > > > it'll
> >> >> > > > > > be a
> >> >> > > > > > > > great
> >> >> > > > > > > > > > contribution, I think.
> >> >> > > > > > > > > >
> >> >> > > > > > > > > > [1]
> >> https://issues.apache.org/jira/browse/IGNITE-14703
> >> >> > > > > > > > > > [2] https://github.com/apache/ignite/pull/9081
> >> >> > > > > > > > > >
> >> >> > > > > > > > > >
> >> >> > > > > > > > > > On Mon, Jun 21, 2021 at 11:11 AM Atri Sharma <
> >> >> > atri@apache.org>
> >> >> > > > > > > wrote:
> >> >> > > > > > > > > >
> >> >> > > > > > > > > > > Hi All,
> >> >> > > > > > > > > > >
> >> >> > > > > > > > > > > I have been looking into our text queries support
> >> and
> >> >> > > > > > > > > > > see
> >> >> > > > that it
> >> >> > > > > > > has
> >> >> > > > > > > > > > > limited community support.
> >> >> > > > > > > > > > >
> >> >> > > > > > > > > > > Therefore, I volunteer to be the maintainer of the
> >> >> > module and
> >> >> > > > > > work
> >> >> > > > > > > on
> >> >> > > > > > > > > > > enhancing it further.
> >> >> > > > > > > > > > >
> >> >> > > > > > > > > > > First goal would be to move to Lucene 8.x, then
> >> >> > > > > > > > > > > work
> >> >> > > > > > > > > > > on
> >> >> > > > sorted
> >> >> > > > > > > reduce
> >> >> > > > > > > > > > > - merge across nodes. Fundamentally, this is
> >> >> > > > > > > > > > > doable
> >> >> > > > > > > > > > > since
> >> >> > > > Lucene
> >> >> > > > > > > > ranks
> >> >> > > > > > > > > > > documents according to their score, and documents
> >> are
> >> >> > > > returned in
> >> >> > > > > > > the
> >> >> > > > > > > > > > > order of their score. Since the scoring function
> >> >> > > > > > > > > > > is
> >> >> > > > homogeneous,
> >> >> > > > > > > this
> >> >> > > > > > > > > > > means that across nodes, we can compare scores and
> >> >> > > > > > > > > > > merge
> >> >> > > > sort.
> >> >> > > > > > > > > > >
> >> >> > > > > > > > > > > Please let me know if I can take this up.
> >> >> > > > > > > > > > >
> >> >> > > > > > > > > > > Atri
> >> >> > > > > > > > > > >
> >> >> > > > > > > > > > > --
> >> >> > > > > > > > > > > Regards,
> >> >> > > > > > > > > > >
> >> >> > > > > > > > > > > Atri
> >> >> > > > > > > > > > > Apache Concerted
> >> >> > > > > > > > > > >
> >> >> > > > > > > > > >
> >> >> > > > > > > > >
> >> >> > > > > > > > >
> >> >> > > > > > > > > --
> >> >> > > > > > > > >
> >> >> > > > > > > > > Best regards,
> >> >> > > > > > > > > Alexei Scherbakov
> >> >> > > > > > > >
> >> >> > > > > > > > --
> >> >> > > > > > > > Regards,
> >> >> > > > > > > >
> >> >> > > > > > > > Atri
> >> >> > > > > > > > Apache Concerted
> >> >> > > > > > > >
> >> >> > > > > > >
> >> >> > > > > >
> >> >> > > > >
> >> >> > > > >
> >> >> > > > > --
> >> >> > > > > Best regards,
> >> >> > > > > Andrey V. Mashenkov
> >> >> > > >
> >> >> > > > --
> >> >> > > > Regards,
> >> >> > > >
> >> >> > > > Atri
> >> >> > > > Apache Concerted
> >> >> > > >
> >> >> > >
> >> >> > >
> >> >> > > --
> >> >> > > Best regards,
> >> >> > > Andrey V. Mashenkov
> >> >> >
> >> >> > --
> >> >> > Regards,
> >> >> >
> >> >> > Atri
> >> >> > Apache Concerted
> >> >> >
> >> >>
> >> >>
> >> >> --
> >> >> Best regards,
> >> >> Andrey V. Mashenkov
> >> >
> >> > --
> >> > Regards,
> >> >
> >> > Atri
> >> > Apache Concerted
> >> >
> >>
> >>
> >> --
> >>
> >> Best regards,
> >> Ivan Pavlukhin
> >>
> >
>
>
> --
>
> Best regards,
> Ivan Pavlukhin
--
Regards,
Atri
Apache Concerted
Re: Text Queries Support
Posted by Ivan Pavlukhin <vo...@gmail.com>.
Hi Atri,
My main concern is non-maleficence. Every task has several solutions,
e.g. straightforward ones:
1. Do not implement FTS.
2. Create own implementation.
Some of the strongest ones live without FTS [1].
[1] https://github.com/cockroachdb/cockroach/issues/7821
2021-08-02 11:33 GMT+03:00, Atri Sharma <at...@apache.org>:
> Hi Ivan,
>
> Would you like to propose an alternative to Lucene?
>
> Atri
>
> On Mon, 2 Aug 2021, 13:48 Ivan Pavlukhin, <vo...@gmail.com> wrote:
>
>> Folks,
>>
>> Sorry if read the thread not thoroughly enough, but do we consider
>> Lucene as obviously right choice? In my understanding Ignite history
>> has shown clearly that "fastest feature implementation" is not usually
>> the best. And one example of this are text queries. Are not we trying
>> to do a same mistake again? FTS is a huge feature, I do not believe
>> there is an easy win for it.
>>
>> 2021-07-27 19:18 GMT+03:00, Atri Sharma <at...@apache.org>:
>> > Andrey,
>> >
>> >> Per-partition Lucene index looks simple to implement, but it may
>> >> require
>> >> per-partition SQL to make full-text search expressions work correctly
>> >> within the SQL quiery.
>> > I think that as long as we follow the map - reduce process that we
>> > already do for other queries, we should be fine.
>> >
>> >> Per-partition SQL index may kill the performance. We already tried to
>> >> do
>> >> that in Ignite 2. However, QueryParallelism feature helps to speed up
>> >> some
>> >> data-intensive queries,
>> >> but hits the performance in simple cases, and at some point (e.g.
>> >> segments
>> >> > number of CPU) the performance rapidly degrades with the increasing
>> >> number of segments.
>> >
>> > Yeah, that is always the case, but a global index will be a nightmare
>> > in terms of concurrency and pessimistic concurrency control will
>> > anyways kill the benefits, coupled with the metadata requirements.
>> > What were the specific issues with per partition index?
>> >>
>> >> AFAIK, Lucene widely used bitmap indices that are easy to merge.
>> >> Maybe, the map-reduce technique underneath FTS expressions and some
>> hacks
>> >> will add a minimal overhead.
>> >
>> > Lucene uses many types of indices but the aspect here is that per
>> > partition Lucene indices can return docIDs and we can merge them in
>> > reduce phase. So we are abstracted out from specifics of the internal
>> > index being used to serve the query.
>> >
>> >>
>> >> > As illustrated by Ilya, we can use Ignite's WAL records to rebuild
>> >> > Lucene indices. The important thing here is to not treat Lucene
>> >> > indices as source of truth.
>> >> To use WAL we either should relay Lucene files to our Page memory or
>> >> be
>> >> aware of Lucene files structure.
>> >> The first looks tricky, as we should guarantee a contiguous address
>> space
>> >> in Page memory for reflecting Lucene file. Maybe separate managed
>> >> memory
>> >> segment with its own rules?
>> >
>> > Why not use Lucene's MMappedDirectory and map it to our storage
>> > classes?
>> >
>> >>
>> >> >> Transactions.
>> >> >> * Will we support transactions?
>> >> > Lucene has no concept of transactions.
>> >> Yes, but we have.
>> >> Lucene index may be non-transactional, but users never expect to see
>> >> uncommited data.
>> >> How does this connect with transactional SQL?
>> > We could have the Lucene writes done as a part of transactions and ack
>> > back only when it succeeds/fails. WDYT?
>> >>
>> >> On Tue, Jul 27, 2021 at 1:36 PM Atri Sharma <at...@apache.org> wrote:
>> >>
>> >> > Sorry, I planned on creating a Wiki page for this, but it makes more
>> >> > sense to be replying here.
>> >> >
>> >> > > * How Lucene index can be split among the nodes?
>> >> >
>> >> > We can have partition level indices on each node.
>> >> >
>> >> > > * If we'll have a single index for all partitions on the
>> >> > > particular
>> >> > > node,
>> >> > > then how index records will be aware of partitioning?
>> >> >
>> >> > Index records dont need to be aware of partitioning -- each Lucene
>> >> > index is independent.
>> >> >
>> >> > > This is important to filter out backup records from the results to
>> >> > > avoid
>> >> > > duplicates.
>> >> >
>> >> > We can merge documents from different nodes and remove duplicates as
>> >> > long as docIDs are globally unique.
>> >> >
>> >> > > * How results from several nodes can be merged on the Reduce
>> >> > > stage?
>> >> >
>> >> > As long as documents have a globally unique docID, Lucene has merge
>> >> > functions that can merge results from multiple partial results.
>> >> >
>> >> > > * Does Lucene supports smth like JOIN operation or others that may
>> >> > require
>> >> > > data from another partition or index?
>> >> >
>> >> > As illustrated by Ilya, Block-Join works for us.
>> >> >
>> >> > > If so, then it likes to multistep query with merging results on
>> >> > > intermediate stages and requires detailed investigation and
>> >> > > design.
>> >> > > It is ok if Ignite will have some limitations here, but we would
>> like
>> >> > > to
>> >> > > know about them at the early stage.
>> >> >
>> >> > > * How effectively map Lucene files to the page memory? Is it even
>> >> > possible?
>> >> >
>> >> > Lucene has PageDirectory implementations which allow storing Lucene
>> >> > indices on different kind of file structures. It has a
>> >> > MMappedFileDirectory that we could use?
>> >> >
>> >> > > Otherwise, how to deal with potential OOM on large queries and
>> memory
>> >> > > capacity planning?
>> >> >
>> >> > We can use Lucene's MMapped directory.
>> >> >
>> >> > >
>> >> > > Persistence.
>> >> > > * How and what consistency guarantees could we have/expect?
>> >> >
>> >> > Lucene does not have WAL logs but is append only
>> >> >
>> >> > > Seems, we may not be able to write physical records for Lucene
>> >> > > index
>> >> > > to
>> >> > our
>> >> > > WAL. What can we do with this?
>> >> >
>> >> > As illustrated by Ilya, we can use Ignite's WAL records to rebuild
>> >> > Lucene indices. The important thing here is to not treat Lucene
>> >> > indices as source of truth.
>> >> > >
>> >> > > Transactions.
>> >> > > * Will we support transactions?
>> >> > Lucene has no concept of transactions.
>> >> >
>> >> > > * Should Lucene be aware of Transaction and track mvcc (or
>> >> > > whatever)
>> >> > > versions for the records?
>> >> > No
>> >> > > * What will be consistency guarantees?
>> >> > We can acknowledge writes back only after Lucene index is updated.
>> >> > >
>> >> > > UX
>> >> > > * How to add FullText search queries syntax into Calcite?
>> >> > Postgres's FTS functions are a good reference.
>> >> > > * AFAIK, the Lucene index has many properties for tuning. How will
>> >> > > the
>> >> > user
>> >> > > configure the index?
>> >> > Most of those properties can be cluster level and exposed as a new
>> >> > sub
>> >> > config for ignite.
>> >> > > * How and where to store the settings? What are cluster-wide and
>> what
>> >> > > a
>> >> > > local to the particular node?
>> >> > All can be cluster level.
>> >> > > * Will be all the settings immutable? Can be they changed on-fly?
>> >> > > after
>> >> > > node/grid restart?
>> >> > They should be applied post restart.
>> >> >
>> >> > > * Any limitations on query syntax?
>> >> > It depends on how we model our queries for text search.
>> >> >
>> >> > >
>> >> > > SQL
>> >> > > * Will we support FullText search in SQL?
>> >> > We need custom functions for it. See Postgres's FTS functions.
>> >> > > * How to integrate Lucene index into Calcite? What is the cost
>> model?
>> >> > There cannot be any cost model since there are no paths for a text
>> >> > query. If we see a text query, we have to use Lucene index or return
>> >> > an error. In this way, we need to model text search as a set of UDFs
>> >> >
>> >> > > Splitting rules? Traits?
>> >> > Please see my reply above.
>> >> > >
>> >> > >
>> >> > > With all of this, you can go with the IEP (or even some short
>> >> > > summary)
>> >> > and
>> >> > > further POC and implementation.
>> >> > > That's a big deal, so let's discuss what could be done here.
>> >> > >
>> >> > > On Fri, Jul 23, 2021 at 12:58 PM Atri Sharma <at...@apache.org>
>> wrote:
>> >> > >
>> >> > > > I am actually happy to drive the feature for Ignite 3. FTS is
>> >> > > > very
>> >> > > > important for me and I think Ignite users will benefit from it
>> >> > > > greatly.
>> >> > > >
>> >> > > > If it makes sense to be focusing on Ignite 3 for this
>> >> > > > capability,
>> I
>> >> > > > am
>> >> > > > eager to contribute there and lead the development.
>> >> > > >
>> >> > > > Please share your thoughts.
>> >> > > >
>> >> > > > On Fri, Jul 23, 2021 at 3:21 PM Andrey Mashenkov
>> >> > > > <an...@gmail.com> wrote:
>> >> > > > >
>> >> > > > > Hi Atri,
>> >> > > > >
>> >> > > > > All the Jira tickets we have on the Full-text search (FTS)
>> >> > > > > thing
>> >> > > > > are
>> >> > > > > targeted to Ignite 2.
>> >> > > > >
>> >> > > > > AFAIK, we want, but we have NOT committed to FTS support in
>> Ignite
>> >> > > > > 3,
>> >> > > > yet.
>> >> > > > > By the way, we are getting requests for this thing from the
>> >> > > > > user
>> >> > side,
>> >> > > > and
>> >> > > > > definitely,
>> >> > > > > FTS would be a valuable feature for Ignite.
>> >> > > > >
>> >> > > > > It will be great if the one wants to drive it, any help will
>> >> > > > > be
>> >> > > > appreciated.
>> >> > > > >
>> >> > > > >
>> >> > > > > On Fri, Jul 23, 2021 at 12:12 PM Atri Sharma <at...@apache.org>
>> >> > wrote:
>> >> > > > >
>> >> > > > > > Hello,
>> >> > > > > >
>> >> > > > > > An update, please. I am working through persistence of
>> >> > > > > > Lucene
>> >> > > > > > index
>> >> > > > using
>> >> > > > > > Ignite Dictionary, and will be asking some questions soon.
>> >> > > > > >
>> >> > > > > > I had one doubt - - where does this change go? Ignite 3?
>> >> > > > > >
>> >> > > > > > Also, I know we want to build native support for text
>> >> > > > > > searches
>> >> > > > > > in
>> >> > > > Ignite 3.
>> >> > > > > > Is the work I am proposing here part of that, or will that
>> >> > > > > > be
>> a
>> >> > > > separate
>> >> > > > > > effort?
>> >> > > > > >
>> >> > > > > > On Mon, 28 Jun 2021, 19:20 Ilya Kasnacheev, <
>> >> > ilya.kasnacheev@gmail.com
>> >> > > > >
>> >> > > > > > wrote:
>> >> > > > > >
>> >> > > > > > > Hello!
>> >> > > > > > >
>> >> > > > > > > I think that number one is the most important one, then
>> maybe
>> >> > > > > > > it
>> >> > > > will see
>> >> > > > > > > more use and other deficiencies become more apparent,
>> leading
>> >> > > > > > > to
>> >> > more
>> >> > > > > > > tickets and visibility.
>> >> > > > > > >
>> >> > > > > > > Maybe 2. and 3. will even use a different approach when
>> >> > persistence
>> >> > > > is
>> >> > > > > > > implemented.
>> >> > > > > > >
>> >> > > > > > > Regards,
>> >> > > > > > > --
>> >> > > > > > > Ilya Kasnacheev
>> >> > > > > > >
>> >> > > > > > >
>> >> > > > > > > пн, 28 июн. 2021 г. в 14:34, Atri Sharma
>> >> > > > > > > <at...@apache.org>:
>> >> > > > > > >
>> >> > > > > > > > Hello Again!
>> >> > > > > > > >
>> >> > > > > > > > I have been looking into the aforementioned and here are
>> my
>> >> > follow
>> >> > > > up
>> >> > > > > > > > thoughts:
>> >> > > > > > > >
>> >> > > > > > > > 1. Support persistence of Lucene indexes.
>> >> > > > > > > > 2. https://issues.apache.org/jira/browse/IGNITE-12401
>> >> > > > > > > > (Needs
>> >> > > > fixing of
>> >> > > > > > > > moving partitions first)
>> >> > > > > > > > 3. Figure out how to return scores from nodes and use
>> >> > > > > > > > them
>> >> > > > > > > > as
>> >> > sort
>> >> > > > > > > > parameters on the coordinator node
>> >> > > > > > > > (https://issues.apache.org/jira/browse/IGNITE-12291)
>> >> > > > > > > >
>> >> > > > > > > > Please let me know if this looks ok to make text queries
>> >> > > > functional?
>> >> > > > > > > >
>> >> > > > > > > > Atri
>> >> > > > > > > >
>> >> > > > > > > > On Mon, Jun 21, 2021 at 2:49 PM Alexei Scherbakov
>> >> > > > > > > > <al...@gmail.com> wrote:
>> >> > > > > > > > >
>> >> > > > > > > > > Hi.
>> >> > > > > > > > >
>> >> > > > > > > > > One of the biggest issues with text queries is a lack
>> >> > > > > > > > > of
>> >> > support
>> >> > > > for
>> >> > > > > > > > lucene
>> >> > > > > > > > > indices persistence, which makes this functionality
>> >> > > > > > > > > useless
>> >> > if a
>> >> > > > > > > > > persistence is enabled.
>> >> > > > > > > > >
>> >> > > > > > > > > I would first take care of it.
>> >> > > > > > > > >
>> >> > > > > > > > > пн, 21 июн. 2021 г. в 12:16, Maksim Timonin <
>> >> > > > timonin.maxim@gmail.com
>> >> > > > > > >:
>> >> > > > > > > > >
>> >> > > > > > > > > > Hi, Atri!
>> >> > > > > > > > > >
>> >> > > > > > > > > > You're right, Actually there is a lack of support
>> >> > > > > > > > > > for
>> >> > > > TextQueries.
>> >> > > > > > > For
>> >> > > > > > > > the
>> >> > > > > > > > > > last ticket I'm doing I see some obvious issues with
>> >> > > > > > > > > > them
>> >> > (no
>> >> > > > page
>> >> > > > > > > size
>> >> > > > > > > > > > support, for example). I'm glad that somebody wants
>> >> > > > > > > > > > to
>> >> > maintain
>> >> > > > > > this
>> >> > > > > > > > > > functionality. Thanks a lot!
>> >> > > > > > > > > >
>> >> > > > > > > > > > For the MergeSort algorithm there is already a patch
>> >> > > > > > > > > > for
>> >> > that
>> >> > > > [1].
>> >> > > > > > > It's
>> >> > > > > > > > > > currently on review. This patch introduces an
>> >> > > > > > > > > > abstract
>> >> > reducer
>> >> > > > for
>> >> > > > > > > > > > CacheQueries with 2 implementations (unordered,
>> >> > merge-sort).
>> >> > > > Then
>> >> > > > > > > > TextQuery
>> >> > > > > > > > > > leverages on MergeSort to order results from
>> >> > > > > > > > > > multiple
>> >> > nodes by
>> >> > > > > > score.
>> >> > > > > > > > This
>> >> > > > > > > > > > patch also fixes the pageSize issue, I've mentioned
>> >> > > > > > > > > > before.
>> >> > > > Could
>> >> > > > > > you
>> >> > > > > > > > > > please check if it fully matches your idea? Any
>> >> > > > > > > > > > issues
>> >> > > > > > > > > > or
>> >> > > > comments
>> >> > > > > > > are
>> >> > > > > > > > > > welcome.
>> >> > > > > > > > > >
>> >> > > > > > > > > > I've prepared this ticket, because I need the
>> MergeSort
>> >> > > > algorithm
>> >> > > > > > for
>> >> > > > > > > > the
>> >> > > > > > > > > > new type of queries I'm implementing (IndexQuery, it
>> >> > > > > > > > > > should
>> >> > > > also
>> >> > > > > > > > provide
>> >> > > > > > > > > > ordered results over multiple nodes). Currently I'm
>> not
>> >> > > > planning to
>> >> > > > > > > go
>> >> > > > > > > > > > further with TextQuery, so if you're going to
>> >> > > > > > > > > > support
>> >> > > > > > > > > > this
>> >> > > > it'll
>> >> > > > > > be a
>> >> > > > > > > > great
>> >> > > > > > > > > > contribution, I think.
>> >> > > > > > > > > >
>> >> > > > > > > > > > [1]
>> https://issues.apache.org/jira/browse/IGNITE-14703
>> >> > > > > > > > > > [2] https://github.com/apache/ignite/pull/9081
>> >> > > > > > > > > >
>> >> > > > > > > > > >
>> >> > > > > > > > > > On Mon, Jun 21, 2021 at 11:11 AM Atri Sharma <
>> >> > atri@apache.org>
>> >> > > > > > > wrote:
>> >> > > > > > > > > >
>> >> > > > > > > > > > > Hi All,
>> >> > > > > > > > > > >
>> >> > > > > > > > > > > I have been looking into our text queries support
>> and
>> >> > > > > > > > > > > see
>> >> > > > that it
>> >> > > > > > > has
>> >> > > > > > > > > > > limited community support.
>> >> > > > > > > > > > >
>> >> > > > > > > > > > > Therefore, I volunteer to be the maintainer of the
>> >> > module and
>> >> > > > > > work
>> >> > > > > > > on
>> >> > > > > > > > > > > enhancing it further.
>> >> > > > > > > > > > >
>> >> > > > > > > > > > > First goal would be to move to Lucene 8.x, then
>> >> > > > > > > > > > > work
>> >> > > > > > > > > > > on
>> >> > > > sorted
>> >> > > > > > > reduce
>> >> > > > > > > > > > > - merge across nodes. Fundamentally, this is
>> >> > > > > > > > > > > doable
>> >> > > > > > > > > > > since
>> >> > > > Lucene
>> >> > > > > > > > ranks
>> >> > > > > > > > > > > documents according to their score, and documents
>> are
>> >> > > > returned in
>> >> > > > > > > the
>> >> > > > > > > > > > > order of their score. Since the scoring function
>> >> > > > > > > > > > > is
>> >> > > > homogeneous,
>> >> > > > > > > this
>> >> > > > > > > > > > > means that across nodes, we can compare scores and
>> >> > > > > > > > > > > merge
>> >> > > > sort.
>> >> > > > > > > > > > >
>> >> > > > > > > > > > > Please let me know if I can take this up.
>> >> > > > > > > > > > >
>> >> > > > > > > > > > > Atri
>> >> > > > > > > > > > >
>> >> > > > > > > > > > > --
>> >> > > > > > > > > > > Regards,
>> >> > > > > > > > > > >
>> >> > > > > > > > > > > Atri
>> >> > > > > > > > > > > Apache Concerted
>> >> > > > > > > > > > >
>> >> > > > > > > > > >
>> >> > > > > > > > >
>> >> > > > > > > > >
>> >> > > > > > > > > --
>> >> > > > > > > > >
>> >> > > > > > > > > Best regards,
>> >> > > > > > > > > Alexei Scherbakov
>> >> > > > > > > >
>> >> > > > > > > > --
>> >> > > > > > > > Regards,
>> >> > > > > > > >
>> >> > > > > > > > Atri
>> >> > > > > > > > Apache Concerted
>> >> > > > > > > >
>> >> > > > > > >
>> >> > > > > >
>> >> > > > >
>> >> > > > >
>> >> > > > > --
>> >> > > > > Best regards,
>> >> > > > > Andrey V. Mashenkov
>> >> > > >
>> >> > > > --
>> >> > > > Regards,
>> >> > > >
>> >> > > > Atri
>> >> > > > Apache Concerted
>> >> > > >
>> >> > >
>> >> > >
>> >> > > --
>> >> > > Best regards,
>> >> > > Andrey V. Mashenkov
>> >> >
>> >> > --
>> >> > Regards,
>> >> >
>> >> > Atri
>> >> > Apache Concerted
>> >> >
>> >>
>> >>
>> >> --
>> >> Best regards,
>> >> Andrey V. Mashenkov
>> >
>> > --
>> > Regards,
>> >
>> > Atri
>> > Apache Concerted
>> >
>>
>>
>> --
>>
>> Best regards,
>> Ivan Pavlukhin
>>
>
--
Best regards,
Ivan Pavlukhin
Re: Text Queries Support
Posted by Atri Sharma <at...@apache.org>.
Hi Ivan,
Would you like to propose an alternative to Lucene?
Atri
On Mon, 2 Aug 2021, 13:48 Ivan Pavlukhin, <vo...@gmail.com> wrote:
> Folks,
>
> Sorry if read the thread not thoroughly enough, but do we consider
> Lucene as obviously right choice? In my understanding Ignite history
> has shown clearly that "fastest feature implementation" is not usually
> the best. And one example of this are text queries. Are not we trying
> to do a same mistake again? FTS is a huge feature, I do not believe
> there is an easy win for it.
>
> 2021-07-27 19:18 GMT+03:00, Atri Sharma <at...@apache.org>:
> > Andrey,
> >
> >> Per-partition Lucene index looks simple to implement, but it may require
> >> per-partition SQL to make full-text search expressions work correctly
> >> within the SQL quiery.
> > I think that as long as we follow the map - reduce process that we
> > already do for other queries, we should be fine.
> >
> >> Per-partition SQL index may kill the performance. We already tried to do
> >> that in Ignite 2. However, QueryParallelism feature helps to speed up
> >> some
> >> data-intensive queries,
> >> but hits the performance in simple cases, and at some point (e.g.
> >> segments
> >> > number of CPU) the performance rapidly degrades with the increasing
> >> number of segments.
> >
> > Yeah, that is always the case, but a global index will be a nightmare
> > in terms of concurrency and pessimistic concurrency control will
> > anyways kill the benefits, coupled with the metadata requirements.
> > What were the specific issues with per partition index?
> >>
> >> AFAIK, Lucene widely used bitmap indices that are easy to merge.
> >> Maybe, the map-reduce technique underneath FTS expressions and some
> hacks
> >> will add a minimal overhead.
> >
> > Lucene uses many types of indices but the aspect here is that per
> > partition Lucene indices can return docIDs and we can merge them in
> > reduce phase. So we are abstracted out from specifics of the internal
> > index being used to serve the query.
> >
> >>
> >> > As illustrated by Ilya, we can use Ignite's WAL records to rebuild
> >> > Lucene indices. The important thing here is to not treat Lucene
> >> > indices as source of truth.
> >> To use WAL we either should relay Lucene files to our Page memory or be
> >> aware of Lucene files structure.
> >> The first looks tricky, as we should guarantee a contiguous address
> space
> >> in Page memory for reflecting Lucene file. Maybe separate managed memory
> >> segment with its own rules?
> >
> > Why not use Lucene's MMappedDirectory and map it to our storage classes?
> >
> >>
> >> >> Transactions.
> >> >> * Will we support transactions?
> >> > Lucene has no concept of transactions.
> >> Yes, but we have.
> >> Lucene index may be non-transactional, but users never expect to see
> >> uncommited data.
> >> How does this connect with transactional SQL?
> > We could have the Lucene writes done as a part of transactions and ack
> > back only when it succeeds/fails. WDYT?
> >>
> >> On Tue, Jul 27, 2021 at 1:36 PM Atri Sharma <at...@apache.org> wrote:
> >>
> >> > Sorry, I planned on creating a Wiki page for this, but it makes more
> >> > sense to be replying here.
> >> >
> >> > > * How Lucene index can be split among the nodes?
> >> >
> >> > We can have partition level indices on each node.
> >> >
> >> > > * If we'll have a single index for all partitions on the particular
> >> > > node,
> >> > > then how index records will be aware of partitioning?
> >> >
> >> > Index records dont need to be aware of partitioning -- each Lucene
> >> > index is independent.
> >> >
> >> > > This is important to filter out backup records from the results to
> >> > > avoid
> >> > > duplicates.
> >> >
> >> > We can merge documents from different nodes and remove duplicates as
> >> > long as docIDs are globally unique.
> >> >
> >> > > * How results from several nodes can be merged on the Reduce stage?
> >> >
> >> > As long as documents have a globally unique docID, Lucene has merge
> >> > functions that can merge results from multiple partial results.
> >> >
> >> > > * Does Lucene supports smth like JOIN operation or others that may
> >> > require
> >> > > data from another partition or index?
> >> >
> >> > As illustrated by Ilya, Block-Join works for us.
> >> >
> >> > > If so, then it likes to multistep query with merging results on
> >> > > intermediate stages and requires detailed investigation and design.
> >> > > It is ok if Ignite will have some limitations here, but we would
> like
> >> > > to
> >> > > know about them at the early stage.
> >> >
> >> > > * How effectively map Lucene files to the page memory? Is it even
> >> > possible?
> >> >
> >> > Lucene has PageDirectory implementations which allow storing Lucene
> >> > indices on different kind of file structures. It has a
> >> > MMappedFileDirectory that we could use?
> >> >
> >> > > Otherwise, how to deal with potential OOM on large queries and
> memory
> >> > > capacity planning?
> >> >
> >> > We can use Lucene's MMapped directory.
> >> >
> >> > >
> >> > > Persistence.
> >> > > * How and what consistency guarantees could we have/expect?
> >> >
> >> > Lucene does not have WAL logs but is append only
> >> >
> >> > > Seems, we may not be able to write physical records for Lucene index
> >> > > to
> >> > our
> >> > > WAL. What can we do with this?
> >> >
> >> > As illustrated by Ilya, we can use Ignite's WAL records to rebuild
> >> > Lucene indices. The important thing here is to not treat Lucene
> >> > indices as source of truth.
> >> > >
> >> > > Transactions.
> >> > > * Will we support transactions?
> >> > Lucene has no concept of transactions.
> >> >
> >> > > * Should Lucene be aware of Transaction and track mvcc (or whatever)
> >> > > versions for the records?
> >> > No
> >> > > * What will be consistency guarantees?
> >> > We can acknowledge writes back only after Lucene index is updated.
> >> > >
> >> > > UX
> >> > > * How to add FullText search queries syntax into Calcite?
> >> > Postgres's FTS functions are a good reference.
> >> > > * AFAIK, the Lucene index has many properties for tuning. How will
> >> > > the
> >> > user
> >> > > configure the index?
> >> > Most of those properties can be cluster level and exposed as a new sub
> >> > config for ignite.
> >> > > * How and where to store the settings? What are cluster-wide and
> what
> >> > > a
> >> > > local to the particular node?
> >> > All can be cluster level.
> >> > > * Will be all the settings immutable? Can be they changed on-fly?
> >> > > after
> >> > > node/grid restart?
> >> > They should be applied post restart.
> >> >
> >> > > * Any limitations on query syntax?
> >> > It depends on how we model our queries for text search.
> >> >
> >> > >
> >> > > SQL
> >> > > * Will we support FullText search in SQL?
> >> > We need custom functions for it. See Postgres's FTS functions.
> >> > > * How to integrate Lucene index into Calcite? What is the cost
> model?
> >> > There cannot be any cost model since there are no paths for a text
> >> > query. If we see a text query, we have to use Lucene index or return
> >> > an error. In this way, we need to model text search as a set of UDFs
> >> >
> >> > > Splitting rules? Traits?
> >> > Please see my reply above.
> >> > >
> >> > >
> >> > > With all of this, you can go with the IEP (or even some short
> >> > > summary)
> >> > and
> >> > > further POC and implementation.
> >> > > That's a big deal, so let's discuss what could be done here.
> >> > >
> >> > > On Fri, Jul 23, 2021 at 12:58 PM Atri Sharma <at...@apache.org>
> wrote:
> >> > >
> >> > > > I am actually happy to drive the feature for Ignite 3. FTS is very
> >> > > > important for me and I think Ignite users will benefit from it
> >> > > > greatly.
> >> > > >
> >> > > > If it makes sense to be focusing on Ignite 3 for this capability,
> I
> >> > > > am
> >> > > > eager to contribute there and lead the development.
> >> > > >
> >> > > > Please share your thoughts.
> >> > > >
> >> > > > On Fri, Jul 23, 2021 at 3:21 PM Andrey Mashenkov
> >> > > > <an...@gmail.com> wrote:
> >> > > > >
> >> > > > > Hi Atri,
> >> > > > >
> >> > > > > All the Jira tickets we have on the Full-text search (FTS) thing
> >> > > > > are
> >> > > > > targeted to Ignite 2.
> >> > > > >
> >> > > > > AFAIK, we want, but we have NOT committed to FTS support in
> Ignite
> >> > > > > 3,
> >> > > > yet.
> >> > > > > By the way, we are getting requests for this thing from the user
> >> > side,
> >> > > > and
> >> > > > > definitely,
> >> > > > > FTS would be a valuable feature for Ignite.
> >> > > > >
> >> > > > > It will be great if the one wants to drive it, any help will be
> >> > > > appreciated.
> >> > > > >
> >> > > > >
> >> > > > > On Fri, Jul 23, 2021 at 12:12 PM Atri Sharma <at...@apache.org>
> >> > wrote:
> >> > > > >
> >> > > > > > Hello,
> >> > > > > >
> >> > > > > > An update, please. I am working through persistence of Lucene
> >> > > > > > index
> >> > > > using
> >> > > > > > Ignite Dictionary, and will be asking some questions soon.
> >> > > > > >
> >> > > > > > I had one doubt - - where does this change go? Ignite 3?
> >> > > > > >
> >> > > > > > Also, I know we want to build native support for text searches
> >> > > > > > in
> >> > > > Ignite 3.
> >> > > > > > Is the work I am proposing here part of that, or will that be
> a
> >> > > > separate
> >> > > > > > effort?
> >> > > > > >
> >> > > > > > On Mon, 28 Jun 2021, 19:20 Ilya Kasnacheev, <
> >> > ilya.kasnacheev@gmail.com
> >> > > > >
> >> > > > > > wrote:
> >> > > > > >
> >> > > > > > > Hello!
> >> > > > > > >
> >> > > > > > > I think that number one is the most important one, then
> maybe
> >> > > > > > > it
> >> > > > will see
> >> > > > > > > more use and other deficiencies become more apparent,
> leading
> >> > > > > > > to
> >> > more
> >> > > > > > > tickets and visibility.
> >> > > > > > >
> >> > > > > > > Maybe 2. and 3. will even use a different approach when
> >> > persistence
> >> > > > is
> >> > > > > > > implemented.
> >> > > > > > >
> >> > > > > > > Regards,
> >> > > > > > > --
> >> > > > > > > Ilya Kasnacheev
> >> > > > > > >
> >> > > > > > >
> >> > > > > > > пн, 28 июн. 2021 г. в 14:34, Atri Sharma <at...@apache.org>:
> >> > > > > > >
> >> > > > > > > > Hello Again!
> >> > > > > > > >
> >> > > > > > > > I have been looking into the aforementioned and here are
> my
> >> > follow
> >> > > > up
> >> > > > > > > > thoughts:
> >> > > > > > > >
> >> > > > > > > > 1. Support persistence of Lucene indexes.
> >> > > > > > > > 2. https://issues.apache.org/jira/browse/IGNITE-12401
> >> > > > > > > > (Needs
> >> > > > fixing of
> >> > > > > > > > moving partitions first)
> >> > > > > > > > 3. Figure out how to return scores from nodes and use them
> >> > > > > > > > as
> >> > sort
> >> > > > > > > > parameters on the coordinator node
> >> > > > > > > > (https://issues.apache.org/jira/browse/IGNITE-12291)
> >> > > > > > > >
> >> > > > > > > > Please let me know if this looks ok to make text queries
> >> > > > functional?
> >> > > > > > > >
> >> > > > > > > > Atri
> >> > > > > > > >
> >> > > > > > > > On Mon, Jun 21, 2021 at 2:49 PM Alexei Scherbakov
> >> > > > > > > > <al...@gmail.com> wrote:
> >> > > > > > > > >
> >> > > > > > > > > Hi.
> >> > > > > > > > >
> >> > > > > > > > > One of the biggest issues with text queries is a lack of
> >> > support
> >> > > > for
> >> > > > > > > > lucene
> >> > > > > > > > > indices persistence, which makes this functionality
> >> > > > > > > > > useless
> >> > if a
> >> > > > > > > > > persistence is enabled.
> >> > > > > > > > >
> >> > > > > > > > > I would first take care of it.
> >> > > > > > > > >
> >> > > > > > > > > пн, 21 июн. 2021 г. в 12:16, Maksim Timonin <
> >> > > > timonin.maxim@gmail.com
> >> > > > > > >:
> >> > > > > > > > >
> >> > > > > > > > > > Hi, Atri!
> >> > > > > > > > > >
> >> > > > > > > > > > You're right, Actually there is a lack of support for
> >> > > > TextQueries.
> >> > > > > > > For
> >> > > > > > > > the
> >> > > > > > > > > > last ticket I'm doing I see some obvious issues with
> >> > > > > > > > > > them
> >> > (no
> >> > > > page
> >> > > > > > > size
> >> > > > > > > > > > support, for example). I'm glad that somebody wants to
> >> > maintain
> >> > > > > > this
> >> > > > > > > > > > functionality. Thanks a lot!
> >> > > > > > > > > >
> >> > > > > > > > > > For the MergeSort algorithm there is already a patch
> >> > > > > > > > > > for
> >> > that
> >> > > > [1].
> >> > > > > > > It's
> >> > > > > > > > > > currently on review. This patch introduces an abstract
> >> > reducer
> >> > > > for
> >> > > > > > > > > > CacheQueries with 2 implementations (unordered,
> >> > merge-sort).
> >> > > > Then
> >> > > > > > > > TextQuery
> >> > > > > > > > > > leverages on MergeSort to order results from multiple
> >> > nodes by
> >> > > > > > score.
> >> > > > > > > > This
> >> > > > > > > > > > patch also fixes the pageSize issue, I've mentioned
> >> > > > > > > > > > before.
> >> > > > Could
> >> > > > > > you
> >> > > > > > > > > > please check if it fully matches your idea? Any issues
> >> > > > > > > > > > or
> >> > > > comments
> >> > > > > > > are
> >> > > > > > > > > > welcome.
> >> > > > > > > > > >
> >> > > > > > > > > > I've prepared this ticket, because I need the
> MergeSort
> >> > > > algorithm
> >> > > > > > for
> >> > > > > > > > the
> >> > > > > > > > > > new type of queries I'm implementing (IndexQuery, it
> >> > > > > > > > > > should
> >> > > > also
> >> > > > > > > > provide
> >> > > > > > > > > > ordered results over multiple nodes). Currently I'm
> not
> >> > > > planning to
> >> > > > > > > go
> >> > > > > > > > > > further with TextQuery, so if you're going to support
> >> > > > > > > > > > this
> >> > > > it'll
> >> > > > > > be a
> >> > > > > > > > great
> >> > > > > > > > > > contribution, I think.
> >> > > > > > > > > >
> >> > > > > > > > > > [1]
> https://issues.apache.org/jira/browse/IGNITE-14703
> >> > > > > > > > > > [2] https://github.com/apache/ignite/pull/9081
> >> > > > > > > > > >
> >> > > > > > > > > >
> >> > > > > > > > > > On Mon, Jun 21, 2021 at 11:11 AM Atri Sharma <
> >> > atri@apache.org>
> >> > > > > > > wrote:
> >> > > > > > > > > >
> >> > > > > > > > > > > Hi All,
> >> > > > > > > > > > >
> >> > > > > > > > > > > I have been looking into our text queries support
> and
> >> > > > > > > > > > > see
> >> > > > that it
> >> > > > > > > has
> >> > > > > > > > > > > limited community support.
> >> > > > > > > > > > >
> >> > > > > > > > > > > Therefore, I volunteer to be the maintainer of the
> >> > module and
> >> > > > > > work
> >> > > > > > > on
> >> > > > > > > > > > > enhancing it further.
> >> > > > > > > > > > >
> >> > > > > > > > > > > First goal would be to move to Lucene 8.x, then work
> >> > > > > > > > > > > on
> >> > > > sorted
> >> > > > > > > reduce
> >> > > > > > > > > > > - merge across nodes. Fundamentally, this is doable
> >> > > > > > > > > > > since
> >> > > > Lucene
> >> > > > > > > > ranks
> >> > > > > > > > > > > documents according to their score, and documents
> are
> >> > > > returned in
> >> > > > > > > the
> >> > > > > > > > > > > order of their score. Since the scoring function is
> >> > > > homogeneous,
> >> > > > > > > this
> >> > > > > > > > > > > means that across nodes, we can compare scores and
> >> > > > > > > > > > > merge
> >> > > > sort.
> >> > > > > > > > > > >
> >> > > > > > > > > > > Please let me know if I can take this up.
> >> > > > > > > > > > >
> >> > > > > > > > > > > Atri
> >> > > > > > > > > > >
> >> > > > > > > > > > > --
> >> > > > > > > > > > > Regards,
> >> > > > > > > > > > >
> >> > > > > > > > > > > Atri
> >> > > > > > > > > > > Apache Concerted
> >> > > > > > > > > > >
> >> > > > > > > > > >
> >> > > > > > > > >
> >> > > > > > > > >
> >> > > > > > > > > --
> >> > > > > > > > >
> >> > > > > > > > > Best regards,
> >> > > > > > > > > Alexei Scherbakov
> >> > > > > > > >
> >> > > > > > > > --
> >> > > > > > > > Regards,
> >> > > > > > > >
> >> > > > > > > > Atri
> >> > > > > > > > Apache Concerted
> >> > > > > > > >
> >> > > > > > >
> >> > > > > >
> >> > > > >
> >> > > > >
> >> > > > > --
> >> > > > > Best regards,
> >> > > > > Andrey V. Mashenkov
> >> > > >
> >> > > > --
> >> > > > Regards,
> >> > > >
> >> > > > Atri
> >> > > > Apache Concerted
> >> > > >
> >> > >
> >> > >
> >> > > --
> >> > > Best regards,
> >> > > Andrey V. Mashenkov
> >> >
> >> > --
> >> > Regards,
> >> >
> >> > Atri
> >> > Apache Concerted
> >> >
> >>
> >>
> >> --
> >> Best regards,
> >> Andrey V. Mashenkov
> >
> > --
> > Regards,
> >
> > Atri
> > Apache Concerted
> >
>
>
> --
>
> Best regards,
> Ivan Pavlukhin
>