Fix sharing Agg transition state of DISTINCT or ordered aggs.
If a query contained two aggregates that could share the transition value,
we would correctly collect the input into a tuplesort only once, but
incorrectly run the transition function over the accumulated input twice,
in finalize_aggregates(). That caused a crash, when we tried to call
tuplesort_performsort() on an already-freed NULL tuplestore.
Backport to 9.6, where sharing of transition state and this bug were
introduced.
Analysis by Tom Lane.
Discussion: https://www.postgresql.org/message-id/ac5b0b69-744c-9114-6218-8300ac920e61@iki.fi
Branch
------
master
Details
-------
http://git.postgresql.org/pg/commitdiff/db80acfc9d50ac56811d22802ab3d822ab313055
Modified Files
--------------
src/backend/executor/nodeAgg.c | 21 ++++++++++++++++++---
src/test/regress/expected/aggregates.out | 9 +++++++++
src/test/regress/sql/aggregates.sql | 3 +++
3 files changed, 30 insertions(+), 3 deletions(-)
