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Posted to user@accumulo.apache.org by Andrew Wells <aw...@clearedgeit.com> on 2014/06/30 18:24:47 UTC
Retrieving Rows in Reverse (Descending) Order
Are there currently any good practices on doing this?
Especially when a rowId has a large number of Keys.
--
*Andrew George Wells*
*Software Engineer*
*awells@clearedgeit.com <aw...@clearedgeit.com>*
Re: Retrieving Rows in Reverse (Descending) Order
Posted by David Medinets <da...@gmail.com>.
http://affy.blogspot.com/2012/11/how-can-i-use-reverse-sort-on-generic.html
is one example.
On Mon, Jun 30, 2014 at 12:24 PM, Andrew Wells <aw...@clearedgeit.com>
wrote:
> Are there currently any good practices on doing this?
>
> Especially when a rowId has a large number of Keys.
>
> --
> *Andrew George Wells*
> *Software Engineer*
> *awells@clearedgeit.com <aw...@clearedgeit.com>*
>
>
Re: Retrieving Rows in Reverse (Descending) Order
Posted by Corey Nolet <cj...@gmail.com>.
Donald,
Thanks for the share! Awhile ago, I stumbled across leveldb and I also
pondered the ability to support reverse scanning as a first class feature
in Accumulo. The numbers on that ticket are not surprising, however- we'd
have to assume there'd be a trade-off to make. The trade-off between ingest
throughput and total space consumed vs higher query latency may very well
be worth it for many use cases.
+1 for filing a ticket.
On Mon, Jun 30, 2014 at 12:52 PM, Donald Miner <dm...@clearedgeit.com>
wrote:
> Looks like it was easier said than done for HBase, but they did it:
> https://issues.apache.org/jira/browse/HBASE-4811
>
>
>
>
> On Mon, Jun 30, 2014 at 12:46 PM, Andrew Wells <aw...@clearedgeit.com>
> wrote:
>
>> so, if you need to do both, ascending and descending order. I would need
>> to do 2 writes for each record going in... that might not be possible in
>> our situation.
>>
>>
>> On Mon, Jun 30, 2014 at 12:26 PM, Corey Nolet <cj...@gmail.com> wrote:
>>
>>> Andrew,
>>>
>>> Our recommendation on this has typically been to reverse the sort order
>>> of the keys on ingest.
>>>
>>>
>>> On Mon, Jun 30, 2014 at 12:24 PM, Andrew Wells <aw...@clearedgeit.com>
>>> wrote:
>>>
>>>> Are there currently any good practices on doing this?
>>>>
>>>> Especially when a rowId has a large number of Keys.
>>>>
>>>> --
>>>> *Andrew George Wells*
>>>> *Software Engineer*
>>>> *awells@clearedgeit.com <aw...@clearedgeit.com>*
>>>>
>>>>
>>>
>>
>>
>> --
>> *Andrew George Wells*
>> *Software Engineer*
>> *awells@clearedgeit.com <aw...@clearedgeit.com>*
>>
>>
>
>
> --
>
> Donald Miner
> Chief Technology Officer
> ClearEdge IT Solutions, LLC
> Cell: 443 799 7807
> www.clearedgeit.com
>
Re: Retrieving Rows in Reverse (Descending) Order
Posted by Donald Miner <dm...@clearedgeit.com>.
Looks like it was easier said than done for HBase, but they did it:
https://issues.apache.org/jira/browse/HBASE-4811
On Mon, Jun 30, 2014 at 12:46 PM, Andrew Wells <aw...@clearedgeit.com>
wrote:
> so, if you need to do both, ascending and descending order. I would need
> to do 2 writes for each record going in... that might not be possible in
> our situation.
>
>
> On Mon, Jun 30, 2014 at 12:26 PM, Corey Nolet <cj...@gmail.com> wrote:
>
>> Andrew,
>>
>> Our recommendation on this has typically been to reverse the sort order
>> of the keys on ingest.
>>
>>
>> On Mon, Jun 30, 2014 at 12:24 PM, Andrew Wells <aw...@clearedgeit.com>
>> wrote:
>>
>>> Are there currently any good practices on doing this?
>>>
>>> Especially when a rowId has a large number of Keys.
>>>
>>> --
>>> *Andrew George Wells*
>>> *Software Engineer*
>>> *awells@clearedgeit.com <aw...@clearedgeit.com>*
>>>
>>>
>>
>
>
> --
> *Andrew George Wells*
> *Software Engineer*
> *awells@clearedgeit.com <aw...@clearedgeit.com>*
>
>
--
Donald Miner
Chief Technology Officer
ClearEdge IT Solutions, LLC
Cell: 443 799 7807
www.clearedgeit.com
Re: Retrieving Rows in Reverse (Descending) Order
Posted by Andrew Wells <aw...@clearedgeit.com>.
so, if you need to do both, ascending and descending order. I would need to
do 2 writes for each record going in... that might not be possible in our
situation.
On Mon, Jun 30, 2014 at 12:26 PM, Corey Nolet <cj...@gmail.com> wrote:
> Andrew,
>
> Our recommendation on this has typically been to reverse the sort order of
> the keys on ingest.
>
>
> On Mon, Jun 30, 2014 at 12:24 PM, Andrew Wells <aw...@clearedgeit.com>
> wrote:
>
>> Are there currently any good practices on doing this?
>>
>> Especially when a rowId has a large number of Keys.
>>
>> --
>> *Andrew George Wells*
>> *Software Engineer*
>> *awells@clearedgeit.com <aw...@clearedgeit.com>*
>>
>>
>
--
*Andrew George Wells*
*Software Engineer*
*awells@clearedgeit.com <aw...@clearedgeit.com>*
Re: Retrieving Rows in Reverse (Descending) Order
Posted by Corey Nolet <cj...@gmail.com>.
Andrew,
Our recommendation on this has typically been to reverse the sort order of
the keys on ingest.
On Mon, Jun 30, 2014 at 12:24 PM, Andrew Wells <aw...@clearedgeit.com>
wrote:
> Are there currently any good practices on doing this?
>
> Especially when a rowId has a large number of Keys.
>
> --
> *Andrew George Wells*
> *Software Engineer*
> *awells@clearedgeit.com <aw...@clearedgeit.com>*
>
>