Re: TWO_TASK AND HINTS

In article <1994Feb11.131553.19596_at_cognos.com>, nigelc_at_cognos.com (Nigel Campbell) writes:
> I'm trying to see what the 'real' world has to say about the merits
> or _requirements_ to use the following features.
>
> 1.Installing OpenVMS with the single vs two_task driver. Do the rules
> change if your on an Alpha vs a VAX?

Don't use TWO_TASK. It adds about 5% overhead to your session.

The only time I would use it is when SQL*Net V2 goes production and you get the benefit of a multi-threaded server to overshadow the cost of TWO_TASK.

TWO_TASK is how UNIX boxes work and Oracle Corp. have told us in VMS land not to touch it.

>
> 2.Having to use the hints facility in DML.

Well, we have had to turn off the cost based optimiser for 7.0.13 as it doesn't work. We are relying on the rule based optimiser which seems to work ok. At some later date/version we will try again.

With cost based optimisation turned off you can use the 'hints' to turn it on for a single SELECT statement and if you know the best way to do a query then you can force the optimiser to take that path. Putting in hints also reduces the parse time for the query.

>
>
> --
> Nigel Campbell Voice: (613) 738-1338 ext 3016 P.O. Box 9707
> UNIX/RDBMS Marketing Mgr FAX: (613) 738-0002 3755 Riverside Dr.
> Cognos Incorporated MCI: nigel campbell || 3074729 Ottawa, Ontario
> UUnet: nigelc_at_cognos.COM CANADA K1G 3Z4

Is that what you wanted to hear ?

-- 
Bruce...        pihlab_at_cbr.hhcs.gov.au

"If you swallow a live frog first thing in the morning ...
 Nothing worse will happen to either of you for the rest of the day."

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* Bruce Pihlamae  --  Database Administration                     *
* Commonwealth Department of Human Services and Health            *
* Canberra, Australia                             (W) 06-289-7056 *
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* These are my own thoughts and opinions, few that I have.        *
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