Re: (RE): Calculating LIOs
- From: Tanel Põder <tanel.poder.003@xxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Fri, 13 Aug 2004 22:35:18 +0300
2 small comments after I re-read my post (of course after hitting send
again):
> abbreviations). So if sessions start hitting a lot of never pinned
prefetch
> blocks, the x$kcbkpfs statistics start to indicate inefficient
prefetching,
> thus causing CBO not to favour it and prefer regular single block reads.
What I meant here is that if lot's of never used prefetched blocks are *aged
out*, then the prefetch statistics get worse. If those blocks actually get
used, the stats will be ok.
[snip]
> Note that I'm only concluding my last claim, I've not done testing to see
> whether extra branch blocks actually happen - but I don't see any other
way
I meant here "whether extra branch block READS actually happen"...
Tanel.
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