> Den 2011-06-10 11:11 skrev Pavel Cisar såhär: >>> MaxFileSystemCache is intended for use with SuperServer, where really >>> big FB cache on top of file system cache could be counter productive. >>> Classic and SuperClassic work with very small FB cache (to conserve >>> memory and lower IPC traffic to synchronize them between FB >>> processes/threads). > > Pavel told about MaxFileSystemCache setting which controls if Firebird > will use file system cache or not. This setting was introduced in v2.1 as > FileSystemCacheThreshold and renamed in v2.5 into MaxFileSystemCache. > >> On the other hand, I experienced undesirable file system cache growth >> for a web app with essentially a single connection with a Classic server >> set to default page buffers (75?). >> >> I hade to make OS API calls to limit the file system cache. >> >> This is with a ~50 Gbyte database with two tables containing 150 million >> records each and 50-100 other (smaller) tables. Especially on unindexed >> queries on those large tables, the file system cache tended to grow too >> large, causing performance degradation. >> >> So, what I'm saying is that MaxFileSystemCache may be useful for classic >> as well, in some situations. I haven't tried it though. Still on 2.1. > > And you speak about FileSystemCacheSize setting which was introduced > in v2.5 and allows to limit size of file system cache. This is system-wide > setting and it is fully independent of Firebird's usage of file system cache.
I'm confused now. ;-) I don't find FileSystemCacheSize in firebird.conf, thus I guess it isn't a V2.5 setting? So, in respect to memory usage: Is the worst case that pages are cached in both, Firebird page cache and OS file system cache? Is this possible? Regards, Thomas ------------------------------------------------------------------------------ EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
