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.
>
> https://www.postgresql.org/docs/10/static/sql-createaggregate.html
>
> I was looking at the PostgreSQL 10 source code for some example usages of
> this and was hoping that array_agg and string_agg would support the feature.
I'm not sure how you would parallelize these, since in most uses you
want to have a deterministic output order.
--
Peter Eisentraut http://www.2ndQuadrant.com/
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