Adjust cost model for HashAgg that spills to disk. Tomas Vondra observed that the IO behavior for HashAgg tends to be worse than for Sort. Penalize HashAgg IO costs accordingly.
Also, account for the CPU effort of spilling the tuples and reading them back. Discussion: https://postgr.es/m/20200906212112.nzoy5ytrzjjodpfh@development Reviewed-by: Tomas Vondra Backpatch-through: 13 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/a547e6867527ca16628a3fb1cf3ef6f785210a31 Modified Files -------------- src/backend/optimizer/path/costsize.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
