On 28 March 2012 15:23, Robert Haas <robertmh...@gmail.com> wrote: > At any rate, I strongly agree that counting the number of > strategy allocations is not really a viable proxy for counting the > number of backend writes. You can't know how many of those actually > got dirtied.
Sure. > Since any backend write is necessarily the result of that backend > trying to allocate a buffer, I think maybe we should just count > whether the number of times it was trying to allocate a buffer *using > a BAS* vs. the number of times it was trying to allocate a buffer *not > using a BAS*. That is, decide whether or not it's a "strategy write" > not based on whether the buffer came in via a strategy allocation, but > rather based on whether it's going out as a result of a strategy > allocation. I'm not quite sure I understand what you mean here. Are you suggesting that I produce a revision that bumps beside FlushBuffer() in BufferAlloc(), as a dirty page is evicted/written, while breaking the figure out into != BAS_NORMAL and == BAS_NORMAL figures? Would both figures be presented as separate columns within pg_stat_bgwriter? -- Peter Geoghegan http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training and Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
