Heikki Linnakangas wrote: > Russell Smith wrote: > > 2. Index cleanup is the most expensive part of vacuum. So doing a > > partial vacuum actually means more I/O as you have to do index cleanup > > more often. > > I don't think that's usually the case. Index(es) are typically only a > fraction of the size of the table, and since 8.2 we do index vacuums in > a single scan in physical order. In fact, in many applications the index > is be mostly cached and the index scan doesn't generate any I/O at all. Are _all_ the indexes cached? I would doubt that. Also, for typical table, what percentage is the size of all indexes combined? -- Bruce Momjian bruce@xxxxxxxxxx EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
