Simon Riggs wrote: > When running a VACUUM command we always dirty the block when setting > hint bits, for a number of reasons: > * VACUUM FULL expects all hint bits to be set prior to moving tuples > * Setting all hint bits allows us to truncate the clog > * it forces the VACUUM to write out its own dirty buffers, which is OK, > since it is a background process. > > Other commands call HeapTupleSatisfiesVacuum(), yet these tasks can be > more flexible with hint bit setting. These include ANALYZE, CREATE > INDEX, CLUSTER, HOT pruning and index scan marking deleted tuples (with > changes in all index AMs). This means we have to differentiate between > VACUUM and other callers of HeapTupleSatisfiesVacuum(). > > So the patch changes the APIs of HeapTupleSatisfiesVacuum(), > SetBufferCommitInfoNeedsSave() and SetHintBits() with changes to 13 AM > and command files. There are many changes in tqual.c, which seems the > right way because SetHintBits() is inlined. These make the patch fairly > large, though most of it is simple changes.
If only VACUUM is going to set "flexible" to off, maybe it's better to leave the APIs as they are and have a global that's set by VACUUM only (and reset in a PG_CATCH block). -- Alvaro Herrera http://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
