Fix cost_incremental_sort for expressions with varno 0 When estimating the number of pre-sorted groups in cost_incremental_sort we must not pass Vars with varno 0 to estimate_num_groups, which would cause failues in find_base_rel. This may happen when sorting output of set operations, thanks to generate_append_tlist.
Unlike recurse_set_operations we can't easily access the original target list, so if we find any Vars with varno 0, we fall back to the default estimate DEFAULT_NUM_DISTINCT. Reported-by: Justin Pryzby Discussion: https://postgr.es/m/20200411214639.GK2228%40telsasoft.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/de0dc1a84710f127fdd40f87e783797cc2d69a77 Modified Files -------------- src/backend/optimizer/path/costsize.c | 54 ++++++++++++++++++++++++-- src/test/regress/expected/incremental_sort.out | 20 ++++++++++ src/test/regress/sql/incremental_sort.sql | 4 ++ 3 files changed, 75 insertions(+), 3 deletions(-)
