> It really has very little impact. It only affects index scans, and > even then only if effective_cache_size is less than the size of the > table. > > Essentially, when this kicks in, it models the effect that if you are > index scanning a table much larger than the size of your cache, you > might have to reread some blocks that you previously read in during > *that same index scan*. Ok, thanks for clearing that up for me. Still, I think the doc could be improved on this point (sorry to be a bit obsessed with that, but I'm one of the french translators, so I like the doc to be perfect :) ) -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance