Re: win32 performance - fsync question

In <4214B68C.8000901@dunslane.net>, on 02/17/05   at 10:21 AM, Andrew Dunstan  said:



>E.Rodichev wrote:

>>
>> This problem is addressed by file system (fsck, journalling etc.).
>> Is it reasonable to handle it directly within application?
>>
>>

>In the words of the Duke of Wellington, "If you believe that you'll 
>believe anything."

>Please review past discussions on the mailing lists on this point.

>BTW, most journalling file systems do not guarantee file integrity, only 
>file metadata integrity. In particular, I believe this is tru of NTFS 
>(and whether it even does that has been debated).

>So by all means turn off fsync if you want the performance gain *and* 
>you accept the risk. But if you do, don't come crying later that your 
>data has been lost or corrupted.

>(the results are interesting, though - with fsync off Windows and Linux 
>are in the same performance ballpark.)

>cheers

>andrew

In anything I've done, Windows is very slow when you use fsync or the
Windows API equivalent.

If you need the performance, you had better have the machine hooked up to
a UPS (probably a good idea in any case) and set up something that is
triggered by the UPS running down to signal postgreSQL to do an immediate
shutdown.

-- 
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lsunley@mb.sympatico.ca
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