Re: CPU_COUNT doesn't change after upgrade

From: Erik Trolle <erik_trolle_at_hp.com>
Date: Wed, 29 Dec 1999 16:41:31 +0800
Message-ID: <84chdm$pos$1@web1.cup.hp.com>

cpu_count will not affect parallel query speed. HP-UX and not Oracle controls CPU scheduling. Parallel query works even on sinle CPU systems.

cpu_count affects cpu usage only. With cpu_count > 1 Oracle will spin on latches, waiting for the latch to be released by another CPU. With cpu_count = 1 Oracle will forget about spinning and force a context switch at once. Thus cpu-count affects CPU overhead only.

With 4 CPUs you should set cpu_count = 4

Erik Trolle

Tommy Yuen wrote in message <84bubt$9lp$1_at_hfc.pacific.net.hk>...
>Hi,
>
>We are using Oracle 7.3.4.4.1 on HP-UX 10.20.
>
>After we upgraded the server from 2 CPUs to 4 CPUs,
>The cpu_count parameters displayed by the show parameters command
>in server manager doesn't changed. It is still 1, not 3.
>
>I think this may affect the parallel query speed since it may not use
>the new CPUs for parallel query.
>
>Do anyone have any ideas about this?
>Tommy
>
>
Received on Wed Dec 29 1999 - 02:41:31 CST