Shridhar Daithankar <[EMAIL PROTECTED]> writes: > I was thinking about it. How about vacuuming a page when it is been > pushed out of postgresql buffer cache? It is is memory so not much IO > is involved.
You keep ignoring the problem of removing index entries. To vacuum an individual page, you need to be willing to read in (and update) all index pages that reference the tuples-to-be-deleted. This is hardly tenable when the reason for pushing the page out of buffer cache was so that you could read in something else instead --- you don't have spare buffer slots, and you don't want to do all that I/O (and the associated WAL log entries) before you can read in the page you originally wanted. The latter point is really the crux of the problem. The point of having the VACUUM process is to keep maintenance work out of the critical path of foreground queries. Anything that moves even part of that maintenance work into the critical path is going to be a net loss. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster