Fix hash index vs "snapshot too old" problemms Hash indexes are not WAL-logged, and so do not maintain the LSN of index pages. Since the "snapshot too old" feature counts on detecting error conditions using the LSN of a table and all indexes on it, this makes it impossible to safely do early vacuuming on any table with a hash index, so add this to the tests for whether the xid used to vacuum a table can be adjusted based on old_snapshot_threshold.
While at it, add a paragraph to the docs for old_snapshot_threshold which specifically mentions this and other aspects of the feature which may otherwise surprise users. Problem reported and patch reviewed by Amit Kapila Branch ------ master Details ------- http://git.postgresql.org/pg/commitdiff/2cc41acd8fa3ebb8f0501c6102a253fb7053cf46 Modified Files -------------- doc/src/sgml/config.sgml | 13 ++++++++++ src/backend/access/hash/hash.c | 1 - src/backend/access/hash/hashsearch.c | 4 ---- src/backend/utils/cache/relcache.c | 46 ++++++++++++++++++++++++++++++++++++ src/backend/utils/time/snapmgr.c | 3 ++- src/include/utils/rel.h | 1 + 6 files changed, 62 insertions(+), 6 deletions(-) -- Sent via pgsql-committers mailing list (pgsql-committers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers