Skip system attributes when applying mvdistinct stats
When estimating number of distinct groups, we failed to ignore system
attributes when matching the group expressions to mvdistinct stats,
causing failures like
ERROR: negative bitmapset member not allowed
Fix that by simply skipping anything that is not a regular attribute.
Backpatch to PostgreSQL 10, where the extended stats were introduced.
Bug: #16111
Reported-by: Tuomas Leikola
Author: Tomas Vondra
Backpatch-through: 10
Discussion: https://postgr.es/m/16111-687799584c3a7e73@postgresql.org
Branch
------
REL_12_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/28555a53cb75d00ed0e73f63a6481b4fffcc3dea
Modified Files
--------------
src/backend/utils/adt/selfuncs.c | 19 ++++++++++++++-----
src/test/regress/expected/stats_ext.out | 7 +++++++
src/test/regress/sql/stats_ext.sql | 3 +++
3 files changed, 24 insertions(+), 5 deletions(-)