Re: [HACKERS] win32 performance - fsync question

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

"Magnus Hagander" <mha(at)sollentuna(dot)net> writes:
> My results are:
> Fisrt, baseline:
> * Linux, with fsync (default), write-cache disabled: no data corruption
> * Linux, with fsync (default), write-cache enabled: usually no data
> corruption, but two runs which had

That makes sense.

> * Win32, with fsync, write-cache disabled: no data corruption
> * Win32, with fsync, write-cache enabled: no data corruption
> * Win32, with osync, write cache disabled: no data corruption
> * Win32, with osync, write cache enabled: no data corruption. Once I
> got:
> 2005-02-24 12:19:54 LOG:  could not open file "C:/Program
> Files/PostgreSQL/8.0/data/pg_xlog/000000010000000000000010" (log file 0,
> segment 16): No such file or directory
>   but the data in the database was consistent.

It disturbs me that you couldn't produce data corruption in the cases
where it theoretically should occur.  Seems like this is an indication
that your test was insufficiently severe, or that there is something
going on we don't understand.

			regards, tom lane