| From: | Magnus Hagander <magnus(at)hagander(dot)net> | 
|---|---|
| To: | Greg Smith <gsmith(at)gregsmith(dot)com> | 
| Cc: | pgsql-patches(at)postgresql(dot)org | 
| Subject: | Re: New features for pgbench | 
| Date: | 2007-02-13 08:34:50 | 
| Message-ID: | 20070213083450.GB608@svr2.hagander.net | 
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| Lists: | pgsql-patches | 
On Tue, Feb 13, 2007 at 01:08:04AM -0500, Greg Smith wrote:
> On Tue, 13 Feb 2007, Takayuki Tsunakawa wrote:
> 
> >The Win32 APIs that pgbench is using for gettimeofday() (in 
> >src/port/gettimeofday.c) is much lower in resolution than Linux.
> 
> I wasn't aware of this issue, and it certainly makes the whole latency 
> side of pgbench pretty useless on Win32.  There is code in 
> src/include/executor/instrument.h that uses a higher resolution Windows 
> timer API than gettimeofday() does (as you point out, that one is only 
> resolves to one Windows tick, about 15ms).  If I can get a Windows build 
> environment setup, I'll see if I can borrow that solution for pgbench.
As long as you only need to measure time *difference*, those are pretty
easy to use. Different from Unix, but easy. If you need to keep a
counter that contains actual time it can still be done, but it's a bit
more tricky (not really hard, though).
//Magnus
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