Fix creation of duplicate foreign keys on partitions When creating a foreign key in a partitioned table, if some partitions already have equivalent constraints, we wastefully create duplicates of the constraints instead of attaching to the existing ones. That's inconsistent with the de-duplication that is applied when a table is attached as a partition. To fix, reuse the FK-cloning code instead of having a separate code path.
Backpatch to Postgres 11. This is a subtle behavior change, but surely a welcome one since there's no use in having duplicate foreign keys. Discovered by Álvaro Herrera while thinking about a different problem reported by Jesper Pedersen (bug #15587). Author: Álvaro Herrera Discussion: https://postgr.es/m/[email protected] Branch ------ REL_11_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/4dff8935fbab64aef38470424cc57dbda9efa1cf Modified Files -------------- src/backend/commands/tablecmds.c | 39 +++++++++++---- src/test/regress/expected/foreign_key.out | 83 +++++++++++++++++++++++++++++++ src/test/regress/sql/foreign_key.sql | 38 ++++++++++++++ 3 files changed, 150 insertions(+), 10 deletions(-)
