On 25-Apr-07, at 4:54 AM, Heikki Linnakangas wrote:
Paweł Gruszczyński wrote:
To test I use pgBench with default database schema, run for 25,
50, 75 users at one time. Every test I run 5 time to take average.
Unfortunetly my result shows that ext is fastest, ext3 and jfs are
very simillar. I can understand that ext2 without jurnaling is
faster than ext3, it is said that jfs is 40 - 60% faster. I cant
see the difference. Part of My results: (transaction type |
scaling factor | num of clients | tpl | num on transactions | tps
including connection time | tps excliding connection time)
EXT2:
TPC-B (sort of),50,75,13,975|975,338.286682,358.855582
...
Can anyone tell me what`s wrong with my test? Or maybe it is normal?
With a scaling factor of 50, your database size is ~ 1 GB, which
fits comfortably in your RAM. You're not exercising your drives or
filesystem much. Assuming you haven't disabled fsync, the
performance of that test is bound by the speed your drives can
flush WAL commit records to disk.
I wouldn't expect the filesystem to make a big difference anyway,
but you'll see..
If you really believe that jfs is 40 -60% faster ( which I highly
doubt ) you should see this by simply reading/writing a very large
file (2x your memory size) with dd .
Just curious but what data do you have that suggests this 40-60%
number ?
Dave
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
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