>>>> PostgreSQL has one real behavior problem. Updates act as if you do a >>>> delete then an insert, i.e. for transactional isolation, an updated row >>>> is added new, and the old one is marked as deleted. Sessions are all >>>> about updates, and any really active server cluster will expose >>>> PostgreSQL's worst behavior. >>>> >>> I agree. It will slows down thing a *LOT*. >>> >>> But it's faster than files save handler with proper >>> >>> administration, I suppose. >>> >> >> I actually doubt it it will be. An insert into a database like >> PostgreSQL has a lot more overhead than just the basic file manipulation. > > > > Both I and you could be wrong :) > File system like Ext2, uses liner search for dir entry and dir > operation is atomic in OS. This is a lot of overheads. > However, newer FS like ReiserFS/XFS/Ext3 uses Btree for dir > entry that helps a lot. > > PostgreSQL is using MVCC. Therefore, it could be faster for > many session data. It also can share session data with multiple > web servers. > > Anyone care to take benchmarks? > (You need to wait a little more, since session module needed > to be changed to work with pgsql session save handler)
I got a little time to take some simple benchmarks using ApacheBench 1.3d. OS: Linux 2.4.4/glibc 2.2.2 PC: Intel Celeron 433Mhz/384MB RAM/ATA33 EIDE HDD PostgreSQL: 7.1.3 installed on the same PC Filesystem: ReiserFS PHP: Debug enabled 4.2.0-dev/Apache SAPI There are 5000 session data stored already. Addtional 5000 session data is created by "ab -n 5000 <URL>" Files handler: Requests per second: 95.44 [#/sec] (mean) Pgsql handler: Requests per second: 68.98 [#/sec] (mean) If btree is used for index, PostreSQL slows down a lot. I used hash for index. Most of CPU time is used by PostgreSQL during benchmark. If PostgreSQL server is installed in other PC, pgsql result may be close to files handler. Ext2 FS users may get slower performance with files handler. (Or faster for 10K sessions?) -- Yasuo Ohgaki -- PHP Development Mailing List <http://www.php.net/> To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
