Fix possible usage of incorrect UPPERREL_SETOP RelOptInfo 03d40e4b5 allowed dummy UNION [ALL] children to be removed from the plan by checking for is_dummy_rel(). That commit neglected to still account for the relids from the dummy rel so that the correct UPPERREL_SETOP RelOptInfo could be found and used for adding the Paths to.
Not doing this could result in processing of subsequent UNIONs using the same RelOptInfo as a previously processed UNION, which could result in add_path() freeing old Paths that are needed by the previous UNION. The same fix was independently submitted (2 mins later) by Richard Guo. Reported-by: Alexander Lakhin <[email protected]> Author: David Rowley <[email protected]> Discussion: https://postgr.es/m/[email protected] Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/fdda78e361f136ec2b8de579b366c1e66bba1199 Modified Files -------------- src/backend/optimizer/prep/prepunion.c | 8 ++++++-- src/test/regress/expected/union.out | 6 +++--- 2 files changed, 9 insertions(+), 5 deletions(-)
