> I have had a look at your database and it looks like you have been testing
> on Centos using a page cache of 75 (I suspect you may have classic
> installed) - this results in the large number of reads on Centos and
> therefore the slower execution/fetch time.
> Edit your firebird.conf file (most likely found in /opt/firebird/) and
> change the value of DefaultDbCachePages to 2048 (the page cache the super
> server is using on your win 7 machine). Also make sure that
> DefaultDbCachePages is not commented out (no leading #).
>
> Incidentally, if you are using classic on Centos then a much lower page
> cache should also do the trick - perhaps 128 or thereabouts. Below some
> results using your database (note that these are for win7 64bit only,
> however, Centos 5.6 on ext3 yield identical results)
>
>

Hi David,

I have looked test data on CentOS, yes, page cache only 75, it was strange, because I copied test data in Win 7 to CentOS and on Win 7, page cache is 6144 (without any setting). It seem copying database between OS changed the value on page cache.

Anyway I have changed page cache on CentOS to 2048 and compare the result with WinXp 64 bit also with page cache set to 2048 and both OS have same RAM (2 GB) and same hardisk, here are the execution time from flamerobin

WinXP 64 bit, file system NTFS, RAM 2GB, page cache 2048, SATA2 hardisk :
Executing...
Done.
8448859 fetches, 6 marks, 1295 reads, 6 writes.
0 inserts, 0 updates, 0 deletes, 4144093 index, 7748 seq.
Delta memory: 111272 bytes.
Total execution time: 8.758s
Script execution finished.

CentOS 6 64 bit, file system ext4, RAM 2GB, page cache 2048, SATA2 hardisk :
Executing...
Done.
8448872 fetches, 6 marks, 1304 reads, 6 writes.
0 inserts, 0 updates, 0 deletes, 4144093 index, 7748 seq.
Delta memory: 111240 bytes.
Total execution time: 22.027s
Script execution finished.

Result on CentOS 6 still significantly slower then WinXp64. I will do last test with CentOS but this time with ext3 file system, if it is still slower, then I will use WinXp/Win7 64.

Best regards,
Sugiarto