Re: [PATCHES] SRA Win32 sync() code

Hannu Krosing wrote:
> Bruce Momjian kirjutas E, 17.11.2003 kell 03:58:
>
> >
> > OK, let me give you my logic and you can tell me where I am wrong.
> >
> > First, how many backend can a single write process support if all the
> > backends are doing insert/update/deletes? 5? 10? Let's assume 10.
> > Second, once we change write to write/fsync, how much slower will that
> > be? 100x, 1000x? Let's say 10x.
> >
> > So, by my logic, if we have 100 backends all doing updates, we will need
> > 10 * 100 or 1000 writer processes or threads to keep up with that load.
> > That seems quite excessive to me from a context switching and process
> > overhead perspective.
> >
> > Where am I wrong?
>
> Maybe you meant 100/10 instead of 100*10 ;)

I figured 10 backends, but using fsync, they are not 100x slower (10 *
100). However, testing shows fsync is only 3x slower.

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