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@xxxxxxxxxxx 
  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@xxxxxxxxxxx> 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

    --
    http://www.freelists.org/webpage/oracle-l






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