Re: "Throttling" a session's IO

At 10:51 PM Tuesday, Gints Plivna wrote:
>So the biggest problem it seems are not the MVs themselves but the
>fact that these are working at least a few minutes and stealing all
>the system resouces for that time.

Actually only 1 MView refresh currently. Don't know what else might "tip the scales" in the next 6 months.

>So have you investigated resouce manager?

Frankly, NO. It was my understanding (without having read the Docs !) that a) in real life it comes into play only at about 90% utilisation b) it is based on CPU {so I thought that it wouldn't work for I/O}

>BTW dropping and recreating indexes might be faster than maintaining
>them on insert. You can of course measure that yourself but for us it
>really was better solution.

Yes, that is why I added "which I don't need to do " when talking of the drop and create indexes. Actually, I have no indexes on the MView, except the ones where I am testing it for a Fast Refresh so have added ROWIDs from the source tables and indexed the ROWID columns in the MView.

>Also if you are referring directly to MVs but not using query rewrite
>you use synonym just switching it from the first to second and back.
>It seems even if a query is running in session X you can switch it to
>another object (in another session) and X succesfully continues to run
>till the end.

Yes, that should work.

>Gints Plivna

Hemant K Chitale
http://web.singnet.com.sg/~hkchital
and
http://hemantscribbles.blogspot.com
and
http://hemantoracledba.blogspot.com

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