Re: parallel query

In article <3h0qgt$lbc_at_eccdb1.pms.ford.com>, alal1_at_PROBLEM_WITH_INEWS_GATEWAY_FILE says...
>
>
>
>I heard oracle 7.1 has parallel query option.
> I have single query which has process table with 10 million rows
>and fetch around 50000 rows.
> How can I use the paralle query option for this query.

Do you have an SMP or clustered system? If not, parallel query won't help and can hurt performance. If you do have either of these, here's how to get started with parellel query for the instance. For init.ora parameters:

	PARALLEL_MIN_SERVERS = n		
	PARALLEL_MAX_SERVERS = n		

Start with n = # CPUs, test the query, then try doubling them.

        PARALLEL_DEFAULT_SCANSIZE = n

The query coordinator divides the number of blocks in the table by this value to determine the default degree of parallelism (how many query servers will query this table).

Restart the instance then do the query. You can use EXPLAIN PLAN to see how the query is parallelized. See the Oracle 7.1 Documentation Addendum for more info on parallel query.

-- 
Lisa Roderick
Applications Systems Engineering Performance Group   \ Opinions are mine,
Digital Equipment Corporation                                             \   not those of my
Merrimack, NH                                                                        \    employer.
lisa.roderick._at_mko.mts.dec.com