On Fri, May 6, 2011 at 4:07 PM, Shane Hathaway <sh...@hathawaymix.org> wrote: > On 05/06/2011 06:22 AM, Pedro Ferreira wrote: >> But isn't RelStorage supposed be slower than FileStorage/ZEO? > > No, every measurement I've tried suggests RelStorage (with PostgreSQL or > MySQL) is faster than ZEO on the same hardware. ZEO has certainly > gotten faster lately, but RelStorage still seems to have the advantage > AFAICT. OTOH, the speed difference is not dramatic. For many apps it's > not even noticeable. > >>> But remember that throwing more caches at the problem isn't a >>> solution. It's likely the way you store or query the data from the >>> database that's not optimal. >> >> I agree, many things could be improved regarding the data structures we >> use. However, it is also true that we have a large number of objects >> that are rarely changed, and that there is no need to fetch from the DB >> if we can keep them in memory. > > It sounds like you primarily need a bigger and faster cache. If you > want to make minimal changes to your setup, try increasing the size of > your ZEO cache and store the ZEO cache on either a RAM disk (try mount > -t tmpfs none /some/path) or a solid state disk. Remember that seek > time is 5-10 ms with spinning drives, so putting a ZEO cache on a > spinning drive can actually kill performance.
If this on Linux and you have enough RAM, the data should be in the disk cache anyway, so I don't see any benefit to a RAM disk. Jim -- Jim Fulton http://www.linkedin.com/in/jimfulton _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev
