Fix crash with single-input aggregates with multiple sort keys An aggregate's ORDER BY can list the same sort key more than once with different sort operators, and transformDistinctClause() copies such items into the DISTINCT list. So an aggregate with a single input can have several sort keys and several DISTINCT columns.
nodeAgg.c and execExpr.c mistakenly only checked the number of inputs when deciding if a Datum sort was possible. That check must also consider the number of sort keys. Fix by using the Datum sort only for a single input with a single sort key. Also for v16+, fix crash in pre-sorted aggregate code where the uniqslot was only created when the number of inputs for a DISTINCT aggregate was above 1. The uniqslot is required when there are multiple DISTINCT columns, and an ORDER BY clause may cause more than one of these to exist when there's only a single input column. Author: Ayush Tiwari <[email protected]> Reviewed-by: David Rowley <[email protected]> Discussion: https://postgr.es/m/cajtyswxmuo5qzsy_az+86mty2xdbdw_7ub3c4fjwpfacvd_...@mail.gmail.com Backpatch-through: 14 Branch ------ REL_15_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/21a53865fb5a199fc7f234a9f9fce5608a39e581 Modified Files -------------- src/backend/executor/execExpr.c | 10 ++++++---- src/backend/executor/nodeAgg.c | 22 ++++++++++++++-------- src/test/regress/expected/aggregates.out | 17 +++++++++++++++++ src/test/regress/sql/aggregates.sql | 9 +++++++++ 4 files changed, 46 insertions(+), 12 deletions(-)
