2010/3/11 Paul McGarry <paul@xxxxxxxxxxxxxxx>: > I'm basically wondering how the postgresql cache (ie shared_buffers) > and the OS page_cache interact. The general advice seems to be to > assign 1/4 of RAM to shared buffers. > > I don't have a good knowledge of the internals but I'm wondering if > this will effectively mean that roughly the same amount of RAM being > used for the OS page cache will be used for redundantly caching > something the Postgres is caching as well? I have a similar problem but I can't see an answer in this thread. Our dedicated server has 16 GB RAM. Among other settings shared_buffers is 2 GB, effective_cache_size is 12 GB. Do shared_buffers duplicate contents of OS page cache? If so, how do I know if 25% RAM is the right value for me? Actually it would not seem to be true - the less redundancy the better. Another question - is there a tool or built-in statistic that tells when/how often/how much a table is read from disk? I mean physical read, not poll from OS cache to shared_buffers. -- Konrad Garus -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
