On 2014-10-18 14:30:53 -0400, Tom Lane wrote: > Andres Freund <and...@2ndquadrant.com> writes: > > Interestingly we already set PROC_IN_ANALYZE - but we never actually > > look at it. I wonder what it'd take to ignore analyze in > > GetSnapshotData()/GetOldestXmin()... At first sight it looks quite > > doable to not have a snapshot around (or setup to be ignored) while > > acquire_sample_rows() is running. As that's the expensive bit... > > Say what? How is ANALYZE supposed to know which rows are valid > without a snapshot?
I haven't fully investigated it yet. But it's already not using it's own snapshot to determine visibility. Instead it uses GetOldestXmin() + HeapTupleSatisfiesVacuum(). Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
