sathiya psql escribió: > So now everything is in RAM, if i do a count(*) on this table it returns > 327600 in 3 seconds, why it is taking 3 seconds ????? because am sure that > no Disk I/O is happening.
It has to scan every page and examine visibility for every record. Even if there's no I/O involved, there's a lot of work to do. I am not sure if with your hardware it is expected for it to take 3 seconds though. Do you see high CPU usage during that period? -- Alvaro Herrera http://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
