Re: [HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-18 Thread Tomas Vondra
Hi, On 6/7/17 5:52 AM, Regina Obe wrote: On 6/6/17 13:52, Regina Obe wrote: It seems CREATE AGGREGATE was expanded in 9.6 to support parallelization of aggregate functions using transitions, with the addition of serialfunc and deserialfunc to the aggregate definitions.

Re: [HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-08 Thread Ashutosh Bapat
On Wed, Jun 7, 2017 at 10:55 PM, Robert Haas wrote: > On Tue, Jun 6, 2017 at 3:23 PM, David Fetter wrote: >> I'd bet on lack of tuits. > > I expect that was part of it. Another thing to consider is that, for > numeric aggregates, the transition values

Re: [HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-07 Thread Robert Haas
On Tue, Jun 6, 2017 at 3:23 PM, David Fetter wrote: > I'd bet on lack of tuits. I expect that was part of it. Another thing to consider is that, for numeric aggregates, the transition values don't generally get larger as you aggregate, but for something like string_agg(), they

Re: [HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-06 Thread Andres Freund
On 2017-06-07 00:03:15 -0400, Tom Lane wrote: > Andres Freund writes: > > On 2017-06-06 23:32:53 -0400, Peter Eisentraut wrote: > >> I'm not sure how you would parallelize these, since in most uses you > >> want to have a deterministic output order. > > > Unless you specify

Re: [HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-06 Thread Tom Lane
Andres Freund writes: > On 2017-06-06 23:32:53 -0400, Peter Eisentraut wrote: >> I'm not sure how you would parallelize these, since in most uses you >> want to have a deterministic output order. > Unless you specify ORDER BY you don't really have that anyway, consider >

Re: [HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-06 Thread Regina Obe
> On 6/6/17 13:52, Regina Obe wrote: >> It seems CREATE AGGREGATE was expanded in 9.6 to support >> parallelization of aggregate functions using transitions, with the >> addition of serialfunc and deserialfunc to the aggregate definitions. >> >>

Re: [HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-06 Thread Andres Freund
On 2017-06-06 23:32:53 -0400, Peter Eisentraut wrote: > On 6/6/17 13:52, Regina Obe wrote: > > It seems CREATE AGGREGATE was expanded in 9.6 to support parallelization of > > aggregate functions using transitions, with the addition of serialfunc and > > deserialfunc to the aggregate definitions.

Re: [HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-06 Thread Peter Eisentraut
On 6/6/17 13:52, Regina Obe wrote: > It seems CREATE AGGREGATE was expanded in 9.6 to support parallelization of > aggregate functions using transitions, with the addition of serialfunc and > deserialfunc to the aggregate definitions. > >

Re: [HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-06 Thread Andres Freund
On 2017-06-06 12:23:49 -0700, David Fetter wrote: > On Tue, Jun 06, 2017 at 01:52:45PM -0400, Regina Obe wrote: > > It seems CREATE AGGREGATE was expanded in 9.6 to support parallelization of > > aggregate functions using transitions, with the addition of serialfunc and > > deserialfunc to the

Re: [HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-06 Thread David Fetter
On Tue, Jun 06, 2017 at 01:52:45PM -0400, Regina Obe wrote: > It seems CREATE AGGREGATE was expanded in 9.6 to support parallelization of > aggregate functions using transitions, with the addition of serialfunc and > deserialfunc to the aggregate definitions. > >

[HACKERS] Parallel Aggregation support for aggregate functions that use transitions not implemented for array_agg

2017-06-06 Thread Regina Obe
It seems CREATE AGGREGATE was expanded in 9.6 to support parallelization of aggregate functions using transitions, with the addition of serialfunc and deserialfunc to the aggregate definitions. https://www.postgresql.org/docs/10/static/sql-createaggregate.html I was looking at the PostgreSQL 10