On Tue, Dec 28, 2004 at 02:40:52AM -0800, Eric Brown wrote: > I'm building an appliance where I don't want my customers having to > tune postgresql in any way from the configuration when I install it. I > don't even want them to know it is there. Yet in my study of posgresql, > it seems that even conscientious use of a vacuum daemon or cron job in > vacuum's various forms leaves databases after a while much larger and > lower performing than the actual space and performance after a > dump/restore.
<snip> Firstly, you havn't said what version of PostgreSQL you are using. Recent versions behave better. Also, the autovacuum daemon will probably do most of what you want... > My application is multi-threaded and I could care less about the > concurrency afforded by MVCC. I'd rather just update the things in > place and get less postgresql concurrency but more consistent > long-running performance and disk space utilization. > > Is my interpretation correct? Yes. Although, for a simple counter you might be able to use sequences, depending on the exact semantics. They don't take any additional space when you increment them. > Is there a way to turn off MVCC? Nope. This is a Relational Database with everything that entails. If you don't want that, maybe you should look into a database designed to be embedded (SQLDB iirc). > Do fixed sized rows help any? I doubt it. > Is there anybody using this thing in an appliance type application? Probably, but I don't know where... > I'm quite far along with stored-procedures and whatnot, but if > postgresql really isn't the right solution due to these reasons, I'm > curious if anybody has alternate OpenSource suggestions? (I'm actually > migrating from sleepycat bsddb at the moment because I didn't realize > the licensing costs involved there. My needs really aren't that > extensive really - a few associative indexes, cascading delete, etc.) I'd suggest, use the autovacuum daemon, tune your FSM settings to what you expect the load to be and maybe schedule a database-wide REINDEX/VACUUM FULL regularly. We found doing it once a month was enough to keep it tip-top over the long term... Hope this helps, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a > tool for doing 5% of the work and then sitting around waiting for someone > else to do the other 95% so you can sue them.
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