Ignore invalid indexes when enforcing index rules in ALTER TABLE ATTACH PARTITION
A portion of ALTER TABLE .. ATTACH PARTITION is to ensure that the partition being attached to the partitioned table has a correct set of indexes, so as there is a consistent index mapping between the partitioned table and its new-to-be partition. However, as introduced in 8b08f7d, the current logic could choose an invalid index as a match, which is something that can exist when dealing with more than two levels of partitioning, like attaching a partitioned table (that has partitions, with an index created by CREATE INDEX ON ONLY) to another partitioned table. A partitioned index with indisvalid set to false is equivalent to an incomplete partition tree, meaning that an invalid partitioned index does not have indexes defined in all its partitions. Hence, choosing an invalid partitioned index can create inconsistent partition index trees, where the parent attaching to is valid, but its partition may be invalid. In the report from Alexander Lakhin, this showed up as an assertion failure when validating an index. Without assertions enabled, the partition index tree would be actually broken, as indisvalid should be switched to true for a partitioned index once all its partitions are themselves valid. With two levels of partitioning, the top partitioned table used a valid index and was able to link to an invalid index stored on its partition, itself a partitioned table. I have studied a few options here (like the possibility to switch indisvalid to false for the parent), but came down to the conclusion that we'd better rely on a simple rule: invalid indexes had better never be chosen, so as the partition attached uses and creates indexes that the parent expects. Some regression tests are added to provide some coverage. Note that the existing coverage is not impacted. This is a problem since partitioned indexes exist, so backpatch all the way down to v11. Reported-by: Alexander Lakhin Discussion: https://postgr.es/14987634-43c0-0cb3-e075-94d423607...@gmail.com Backpatch-through: 11 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/fc55c7ff8d122feb48aae5889e26499ffe53c0b7 Modified Files -------------- src/backend/commands/tablecmds.c | 8 ++++++-- src/test/regress/expected/indexing.out | 30 ++++++++++++++++++++++++++++++ src/test/regress/sql/indexing.sql | 22 ++++++++++++++++++++++ 3 files changed, 58 insertions(+), 2 deletions(-)
