Igor, Thank you for the hint, I read about the planner, added "vacuum analyze " to my procedures. There is no join in my query but GROUP BY that is taking all the time and I don't know how to tune it. It gets executed by the procedure, the execution time requirement is < 4 sec, but it takes 8-11 sec against 3 partitions , 9 mln rec each, it goes to 22 sec for 5 partitions. I've been testing PostgreSQL performance for the last 2 months, comparing it whith MySQL, PostgreSQL performance with 5+ mln records on the table with 14 columns is worse. Is 14 columns is a big table for Postgres or 5mln rec is a big table? The whole picture is that there are 2 databases : OLTP & "OLAP" that use to be on different machines and on different databases. The new project requires to put it on one database & machine. I preferred Postgres ( poorly designed oltp would not suffer even more on mysql) and now I'm trying to tune OLAP db. thank you. Helen -- View this message in context: http://postgresql.1045698.n5.nabble.com/How-to-see-memory-usage-using-explain-analyze-tp4694962p4709415.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
