Re: Sequential execution of union all

[Li Yang <li...@apache.org>]

That is right. Sub-queries are executed sequentially as of Kylin 2.0.

On Fri, Jul 28, 2017 at 2:16 AM, Alexander Sterligov <st...@joom.it>
wrote:

> Hello!
>
> My fact table has 12 boolean fields and user id. I need to count distinct
> users with has certain combinations of these flags. So I do several
> sub-queries and union all of them.
> This query may take up to one minute and it doesn't depend on number of
> regionservers in hbase.
>
> It looks like sub-queries are executed sequentially. Or maybe segment
> pruning by dictionary is done sequentially.
>
> Am I right?
>
> Best regards,
> Alexander
>

Re: Sequential execution of union all

[Li Yang <li...@apache.org>]

The sequential execution behavior is implied by Calcite as a SQL execution
engine, not much of Kylin's work. The entry point is QueryService.execute()
where the control is passed to Calcite.

On Thu, Aug 10, 2017 at 3:14 PM, Alexander Sterligov <st...@joom.it>
wrote:

> As I understand it is also single threader for joins (not with lookup
> tables, but with different OLAP), am I right?
>
> Could you please guide me where it happens in the code? I would like to
> contribute. Maybe there are already some tickets about it?
>
> On Sun, Aug 6, 2017 at 9:12 AM, Li Yang <li...@apache.org> wrote:
>
>> That is right. Sub-queries are executed sequentially as of Kylin 2.0.
>>
>> On Fri, Jul 28, 2017 at 2:16 AM, Alexander Sterligov <sterligovak@joom.it
>> > wrote:
>>
>>> Hello!
>>>
>>> My fact table has 12 boolean fields and user id. I need to count
>>> distinct users with has certain combinations of these flags. So I do
>>> several sub-queries and union all of them.
>>> This query may take up to one minute and it doesn't depend on number of
>>> regionservers in hbase.
>>>
>>> It looks like sub-queries are executed sequentially. Or maybe segment
>>> pruning by dictionary is done sequentially.
>>>
>>> Am I right?
>>>
>>> Best regards,
>>> Alexander
>>>
>>
>>
>

Re: Sequential execution of union all

[Alexander Sterligov <st...@joom.it>]

As I understand it is also single threader for joins (not with lookup
tables, but with different OLAP), am I right?

Could you please guide me where it happens in the code? I would like to
contribute. Maybe there are already some tickets about it?

On Sun, Aug 6, 2017 at 9:12 AM, Li Yang <li...@apache.org> wrote:

> That is right. Sub-queries are executed sequentially as of Kylin 2.0.
>
> On Fri, Jul 28, 2017 at 2:16 AM, Alexander Sterligov <st...@joom.it>
> wrote:
>
>> Hello!
>>
>> My fact table has 12 boolean fields and user id. I need to count distinct
>> users with has certain combinations of these flags. So I do several
>> sub-queries and union all of them.
>> This query may take up to one minute and it doesn't depend on number of
>> regionservers in hbase.
>>
>> It looks like sub-queries are executed sequentially. Or maybe segment
>> pruning by dictionary is done sequentially.
>>
>> Am I right?
>>
>> Best regards,
>> Alexander
>>
>
>