Re: What is SPIN_COUNT?
Date: 1995/07/10
Message-ID: <3tra5o$3t9_at_redwdnl.redwood.nl>#1/1
"William J. George" <wjgeorge_at_attmail.com> writes:
>Our group recently noticed that SPIN_COUNT was set to 1 on our development
>machine and 2000 on our production machine. What is it? Is it a derived
>value? Where do I find documentation for these parameters?
It is used on multi-processor machines to tune latch (not lock) allocations. When a user wants a latch held by somebody else it will spin 2000 times by default on most SMP machines (ie. try it for 2000 times) then go to sleep on a semaphore.
On single-processor boxes the default value is 1, 0, or simply not used.
The exact behaviour is port-defined and is not documented by Oracle.
>Thanks in advance,
>Bill
You're welcome.
>--
>W. J. George
>wjgeorge_at_attmail.com
Received on Mon Jul 10 1995 - 00:00:00 CEST