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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