Greg Smith wrote: > Ben Chobot wrote: > >On Feb 23, 2010, at 3:06 PM, Ben Chobot wrote: > > > >>I'm looking at the usage count column of pg_buffercache's info, and I'm > >>confused. Several buffers that supposed have LRU values of 5 belong to > >>non-unique indices which supposedly have never been used. As I understand > >>things, that shouldn't happen. Am I missing something? > > > >(And maybe more to the point, when does the LRU go down in value?) > > Usage counts only go up when a page is "pinned" because some backend > requested that particular block for its work via a call to > BufferAlloc with the file/block it needs.
BTW the only reason you don't see buffers having a larger "usage" is that the counters are capped at that value. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
