Horton

Allow parallel aggregate on string_agg and array_agg

David Rowley <drowley@postgresql.org>

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Commit: 16fd03e956540d1b47b743f6a84f37c54ac93dd4
Author: David Rowley <drowley@postgresql.org>
Date: 2023-01-23T04:35:01Z
Releases: 16.0 
Allow parallel aggregate on string_agg and array_agg

This adds combine, serial and deserial functions for the array_agg() and
string_agg() aggregate functions, thus allowing these aggregates to
partake in partial aggregations.  This allows both parallel aggregation to
take place when these aggregates are present and also allows additional
partition-wise aggregation plan shapes to include plans that require
additional aggregation once the partially aggregated results from the
partitions have been combined.

Author: David Rowley
Reviewed-by: Andres Freund, Tomas Vondra, Stephen Frost, Tom Lane
Discussion: https://postgr.es/m/CAKJS1f9sx_6GTcvd6TMuZnNtCh0VhBzhX6FZqw17TgVFH-ga_A@mail.gmail.com

Files

PathChange+/−
doc/src/sgml/func.sgml modified +3 −3
src/backend/optimizer/prep/prepagg.c modified +24 −4
src/backend/parser/parse_agg.c modified +36 −1
src/backend/utils/adt/arrayfuncs.c modified +19 −1
src/backend/utils/adt/array_userfuncs.c modified +624 −0
src/backend/utils/adt/varlena.c modified +191 −16
src/include/catalog/catversion.h modified +1 −1
src/include/catalog/pg_aggregate.dat modified +11 −2
src/include/catalog/pg_proc.dat modified +27 −0
src/include/parser/parse_agg.h modified +2 −0
src/include/utils/array.h modified +3 −0
src/test/regress/expected/aggregates.out modified +98 −0
src/test/regress/sql/aggregates.sql modified +62 −0

Documentation touched

Discussion