RE: MView... Fresh build is much faster than Complete refresh...

  • From: "Robert Freeman" <robertgfreeman@xxxxxxxxx>
  • To: "Zhu,Chao" <zhuchao@xxxxxxxxx>
  • Date: Wed, 22 Aug 2007 08:02:58 -0600

Yes, planning on doing a 10046 today.

A MVGroup refresh does a merge. I'm sure about that.

RF


Robert G. Freeman
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Principal Engineer/Team Manager
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-----Original Message-----
From: Zhu,Chao [mailto:zhuchao@xxxxxxxxx]
Sent: Wednesday, August 22, 2007 1:16 AM
To: robertgfreeman@xxxxxxxxx
Cc: oracle-l
Subject: Re: MView... Fresh build is much faster than Complete
refresh...


take a 10046 trace and do a compare.
maybe it is doing a long delete before refresh, maybe truncate takes long...
i think a single table refresh does the truncate , and refresh within
a group does the delete.


On 8/22/07, Robert Freeman <robertgfreeman@xxxxxxxxx> wrote:
>
>
> So I have this materialized view. When I execute the create materialized
> view command, it takes 32.39 seconds to build. A complete refresh (exec
> dbms_mview.refresh('mview_name','C'); ) from the prompt
> this takes almost 3-4 times longer. Does anyone have any thoughts on why
> this might be so just right off hand. I've not run a 10046 on it yet,  but
I
> thought maybe there is something about MVIEW Full Refreshes that I'm just
> missing.
>
> RF
>
>
>
> Robert G. Freeman
> Oracle Consultant/DBA/Author
> Principal Engineer/Team Manager
> The Church of Jesus Christ of Latter-Day Saints
> Father of Five, Husband of One,
> Author of various geeky computer titles
> from Osborne/McGraw Hill (Oracle Press)
> Oracle Database 11g New Features Now Available for Pre-sales on
Amazon.com!
> BLOG: http://robertgfreeman.blogspot.com/
> Sig V1.2
>


--
Regards
Zhu Chao
www.cnoug.org

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