Create memory context for HashAgg with a reasonable maxBlockSize. If the memory context's maxBlockSize is too big, a single block allocation can suddenly exceed work_mem. For Hash Aggregation, this can mean spilling to disk too early or reporting a confusing memory usage number for EXPLAN ANALYZE.
Introduce CreateWorkExprContext(), which is like CreateExprContext(), except that it creates the AllocSet with a maxBlockSize that is reasonable in proportion to work_mem. Right now, CreateWorkExprContext() is only used by Hash Aggregation, but it may be generally useful in the future. Discussion: https://postgr.es/m/[email protected] Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/50a38f65177ea7858bc97f71ba0757ba04c1c167 Modified Files -------------- src/backend/executor/execUtils.c | 71 +++++++++++++++++++++++++++++++--------- src/backend/executor/nodeAgg.c | 5 +-- src/include/executor/executor.h | 1 + 3 files changed, 58 insertions(+), 19 deletions(-)
