In Postgres 9.5.1 with a shared_buffer cache of 7Gb, a SELECT from a single table that uses an index appears to read the table into the shared_buffer cache. Then, as many times as the exact same SELECT is repeated in the same session, it runs blazingly fast and doesn't even touch the disk. All good. Now, in the *same* session, if a different SELECT from the *same* table, using the *same* index is run, it appears to read the entire table from disk again. Why is this? Is there something about the query that qualifies the contents of the share_buffer cache? Would this act differently for different kinds of indexes? PJ -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
