Have been looking at lazyvacuum.c trying to think of a way of changing the calculation of the stats to ensure that my hot table stats do not get so badly distorted. What I have noticed is that when I reindex my hot table the stats on the table do not seem to change in pg_stat_user_tables (ie they stay bad) but the EXPLAIN for the query starts using the correct index again. The index itself does not seem very bloated but reindex seems to alter the query optimizer choices. I can't see in index.c where side effect would be caused. Why is this? Not sure if this is entirely helpful as reindex takes exclusive lock, but if I used a concurrent rebuild and rename of the index I might be able to work around this. -- View this message in context: http://postgresql.1045698.n5.nabble.com/autovacuum-vacuum-creates-bad-statistics-for-planner-when-it-log-index-scans-0-tp5804416p5808509.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com.
