Re: [pgsql-hackers-win32] win32 performance - fsync question - Mailing list pgsql-hackers

From Magnus Hagander
Subject Re: [pgsql-hackers-win32] win32 performance - fsync question
Date
Msg-id 6BCB9D8A16AC4241919521715F4D8BCE4769D0@algol.sollentuna.se
Whole thread Raw
Responses Changing the default wal_sync_method to open_sync for Win32?  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
I'd like to see this one also considered for 8.0.x, though I'd certainly
like to see some more testing as well. Perhaps it's suitable for the
"8.0.x with extended testing" that is planned for the ARC replacement
code?

It does make a huge difference on win32. While we definitly don't want
to risk data, a 60% speedup in write intensive apps is a *lot*.

//Magnus


>-----Original Message-----
>From: pgsql-hackers-win32-owner@postgresql.org
>[mailto:pgsql-hackers-win32-owner@postgresql.org] On Behalf Of
>Bruce Momjian
>Sent: den 27 februari 2005 01:54
>To: Magnus Hagander
>Cc: Tom Lane; pgsql-hackers@postgresql.org;
>pgsql-hackers-win32@postgresql.org; Merlin Moncure
>Subject: Re: [pgsql-hackers-win32] [HACKERS] win32 performance
>- fsync question
>
>
>
>Patch applied.  Thanks.
>
>I assume this is not approprate for 8.0.X.
>
>---------------------------------------------------------------
>------------
>
>
>Magnus Hagander wrote:
>> > Magnus prepared a trivial patch which added the O_SYNC flag
>> > for windows and mapped it to FILE_FLAG_WRITE_THROUGH in
>> > win32_open.c.
>>
>> Attached is this trivial patch. As Merlin says, it needs some more
>> reliability testing. But the numbers are at least reasonable - it
>> *seems* like it's doing the right thing (as long as you turn
>off write
>> cache). And it's certainly a significant performance increase - it
>> brings the speed almost up to the same as linux.
>>
>>
>> //Magnus
>
>Content-Description: o_sync.patch
>
>[ Attachment, skipping... ]
>
>>
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>--
>  Bruce Momjian                        |  http://candle.pha.pa.us
>  pgman@candle.pha.pa.us               |  (610) 359-1001
>  +  If your life is a hard drive,     |  13 Roberts Road
>  +  Christ can be your backup.        |  Newtown Square,
>Pennsylvania 19073
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