Tom Lane wrote: > Bill Moran <wmoran@xxxxxxxxxxxxxxxxxxxxxxx> writes: > > The entire database was around 28M prior to the upgrades, etc. Immediately > > after the upgrades, it was ~270M. Following a vacuum full, it dropped to > > 165M. Following a database-wide reindex, it dropped to 30M. > > As Alvaro said, vacuum full doesn't shrink indexes but in fact bloats them. > (Worst case, they could double in size, if the vacuum moves every row; > there's an intermediate state where there have to be index entries for > both old and new copies of each moved row, to ensure things are > consistent if the vacuum crashes right there.) > > So the above doesn't sound too unlikely. Perhaps we should recommend > vac full + reindex as standard cleanup procedure. Longer term, maybe > teach vac full to do an automatic reindex if it's moved more than X% of > the rows. Or forget the current vac full implementation entirely, and > go over to something acting more like CLUSTER ... TODO already has: * Improve speed with indexes For large table adjustments during VACUUM FULL, it is faster to reindex rather than update the index. Also, index updates can bloat the index. -- Bruce Momjian bruce@xxxxxxxxxx EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
