Re: direct path write wait

Hi,

It is a DWH query, which has many outer joins. And has "order by" clause as well.

The wait is because of sorts only but cant avoid sorting....

• Original Message ----- From: Paul Drake To: deepak_blr_at_youtele.com Cc: ORACLE-L Sent: Wednesday, December 27, 2006 9:32 PM Subject: Re: direct path write wait

  On 12/27/06, blr_dba <deepak_blr_at_youtele.com> wrote:     Dear Gurus,

    Am having huge amount of waits on "direct path write event". This event has     98% of the total wait time. Now we want to tune it.

  Perhaps you might first want to tune the SQL statements that are causing the writes to tempfiles (sorts, hash_joins, GTT usage)?

  Pd

    We are using Solaris 9 and Oracle 9.2.0.7 .

    After examining the system we found that logging is enabled on the mounted     UFS file systems.

    Need your expert advice on the following...

> How to know whether the UFS is enabled for asynchronous IO or direct IO?
> Which one is better for DWH environments? Pros and cons of each.
> Is filesystem cache is involved in both of the above methods?

    Please suggest the best solution for my environment.

    Looking forward to your ever valuable feedback.

    Deepak

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• ALTER SESSION SET EVENTS 'immediate trace name hanganalyze level 4';

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