Re: Performance monitor signal handler
Bruce Momjian <pgman@candle.pha.pa.us>
From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Samuel Sieb <samuel@sieb.net>, Jan Wieck <JanWieck@Yahoo.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2001-03-17T17:10:37Z
Lists: pgsql-hackers
> ... and a lot more load on the CPU. Same-machine "network" connections > are much cheaper (on most kernels, anyway) than real network > connections. > > I think all of this discussion is vast overkill. No one has yet > demonstrated that it's not sufficient to have *one* collector process > and a lossy transmission method. Let's try that first, and if it really > proves to be unworkable then we can get out the lily-gilding equipment. > But there is tons more stuff to do before we have useful stats at all, > and I don't think that this aspect is the most critical part of the > problem. Agreed. Sounds like overkill. How about a per-backend shared memory area for stats, plus a global shared memory area that each backend can add to when it exists. That meets most of our problem. The only open issue is per-table stuff, and I would like to see some circular buffer implemented to handle that, with a collection process that has access to shared memory. Even better, have an SQL table updated with the per-table stats periodically. How about a collector process that periodically reads though the shared memory and UPDATE's SQL tables with the information. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026