Fix pg_get_publication_tables() failure with concurrent DROP TABLE. pg_get_publication_tables() collects the OIDs of the published tables on its first call, without locking them, and then reopens each table later, once per result row, to compute its column list and fetch its row filter. The reopen used table_open(), which errors out with "could not open relation with OID" if the table has been dropped in the meantime. This could happen for any published table without an explicit column list, which is every table in FOR ALL TABLES and FOR TABLES IN SCHEMA publications, but also FOR TABLE entries without a column list. The failure is common in environments where many tables are created and dropped while publication tables are being queried, e.g. by table synchronization on a subscriber.
Fix by opening every table with try_table_open(), which returns NULL if the relation no longer exists, and skipping the table in that case. Concurrently dropped tables are thus simply absent from the result set, which is the expected point-in-time behavior. As a side effect, tables with an explicit column list, which were previously returned without being opened, are now also locked with AccessShareLock, so the function can block behind concurrent DDL on such tables where it previously did not. Backpatch to v16, where we added the table_open() call in pg_get_publication_tables(). Author: Bharath Rupireddy <[email protected]> Reviewed-by: Bertrand Drouvot <[email protected]> Reviewed-by: shveta malik <[email protected]> Reviewed-by: Ajin Cherian <[email protected]> Reviewed-by: Masahiko Sawada <[email protected]> Reviewed-by: Chao Li <[email protected]> Discussion: https://www.postgresql.org/message-id/CALj2ACVYYooWH-5tJ6cPKkU%2BmutVxwb_z4S%2BqAi-zdrFqxXE2Q%40mail.gmail.com Backpatch-through: 16 Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/63e7a0d2c3c7f80e52ddf216707ccc1d466453a4 Modified Files -------------- src/backend/catalog/pg_publication.c | 52 ++++++++++++++++++---- .../isolation/expected/pub-concurrent-drop.out | 16 +++++++ src/test/isolation/isolation_schedule | 1 + src/test/isolation/specs/pub-concurrent-drop.spec | 36 +++++++++++++++ src/tools/pgindent/typedefs.list | 1 + 5 files changed, 97 insertions(+), 9 deletions(-)
