Bruce, >> That's way low, and frankly it's not worth bothering with this if all >> we're going to get is an incremental increase. In that case, let's just >> set the default to 4MB like Robert suggested. > > Uh, well, 100 backends at 6MB gives us 600MB, and if each backend uses > 3x work_mem, that gives us 1.8GB for total work_mem. This was based on > Andrew's concerns about possible over-commit of work_mem. I can of > course adjust that.
That's worst-case-scenario planning -- the 3X work-mem per backend was: a) Solaris and b) data warehousing In a normal OLTP application each backend averages something like 0.25 * work_mem, since many queries use no work_mem at all. It also doesn't address my point that, if we are worst-case-scenario default-setting, we're going to end up with defaults which aren't materially different from the current defaults. In which case, why even bother with this whole exercise? -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
