Satoshi Nagayasu <[EMAIL PROTECTED]> writes: > I think the stats stuff should be on by default even if it causes > some performance penalty.
> Because when we have performance problems on the production system, > it needs more performance penalty (about 5%~) to measure the stats > by turning their params on. > In real scenario, we always need the performance information, > so we always need to turn. So I want the performance information > can be taken by default. I don't really agree with this argument. I've been reading pgsql-performance for some years now, and I can't recall any incident whatsoever in which we asked somebody for their stats_block_level numbers. To be honest I think those numbers are just about useless. However, in the current state of the system it seems to be nearly free to collect them if we are collecting row-level stats, and since that's happening by default as of 8.3, it's probably worth simplifying the user-visible behavior by collecting both sets of stats if we collect either. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match