Re: Oracle 7.3 - is it SMP aware?

abramswee_at_yahoo.com wrote:
> Does Oracle 7.3 on NT make full use of multi-processors on a single
> system? I am running it on a HP LH/3 dual processor and my performance
> monitor show very 2 distinct patterns of processor utilization, one is
> always high, one is usually quite low. Please advise.

A idle running Oracle database consists of several (about 6 or 7) running
processes (on UNIX) or threads (on NT). These processes/threads are distributed over the available processors by the operating system. All I/O is done by these processes.
Some of these processes can be started multiple times, such as the DatabaseWriter thread. See the parameter 'db_writer_processes' for this.

However for every new session only one process/thread is created to perform the
SQL processing.
An Oracle database will only split the SQL processing when you have installed
the "Parallel Query Option" (not to be confused with Oracle Parallel Server
which offers 1 database on multiple machines). Using the correct parameters on your tables (CREATE TABLE (...) PARALLEL n),
you can put multiple processes to work for 1 single query. The number of processes used is (at least) dependent on the parameters "parallel_min_servers" and "parallel_max_servers", and the number <n>.

HTH

-- 
Erwin Dondorp
<http://www.dondorp.com/>