Zsolt, I am a bit perplexed understanding the meaning of the values of MON$STATEMENTS.MON$STATE.
Here is what I found in the FB 2.5 Release notes: Memory Usage in MON$STATEMENTS and MON$STATE Memory usage statistics in MON$STATEMENTS and MON$STATE represent actual CPU consumption. Tracker reference: CORE-1583<http://tracker.firebirdsql.org/browse/CORE-1583>) The tracker referenced here is not clear on how the MON$STATE represents CPU usage. <SL> MON$State *does not* reflect CPU consumption, it only reflect the operational state of the statement. The tracker details should be updated to reflect the true nature of the change made.