Re: [PATCHES] SRA Win32 sync() code

Hannu Krosing <hannu@tm.ee>

From: Hannu Krosing <hannu@tm.ee>
To: Bruce Momjian <pgman@candle.pha.pa.us>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL-patches <pgsql-patches@postgresql.org>, PostgreSQL Win32 port list <pgsql-hackers-win32@postgresql.org>
Date: 2003-11-17T10:28:34Z
Lists: pgsql-hackers
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 ;)

------------
Hannu