Re: Excessive Logical and Physical I/O

> I think what he is asking is, if there is 1M worth of blocks to be
> consistent in a 1G RBS, might Oracle have to look through the whole 1G
> to get that 1M. And I think the answer would be the rollback headers
> track where the info is by block, so it shouldn't be a problem.
> http://www.ixora.com.au/q+a/undo.htm might help clarify some. And as
> you said, extent allocation is the real problem, so I would add, size
> the extents so the transactions fit in them.

I thought I already answered this question in a previous post to this thread where I said "Building a read consistent image is on a block by block basis. If one user only needs 1MB of read consistent images, then they only rebuild the number of blocks to satisfy that request."

I guess I wasn't clear enough. :(

> I somewhat agree with the pain/joy thing, but have to point out that
> habitually doing things "correctly" will put off the pain, since
> performance on a multiuser system is a summation of usage. The
> obvious pitfall is over-administrating, that is, spending lots of time
> trying to get the nth incremental bit of performance.

Couldn't agree more.

Cheers,
Brian

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