Re: troubleshooting slow I/O performance.

10ms isn’t bad depending on the I/O? Is it spinning disk or flash? Also is your query running an optimal plan? If you get stuck with a nested loop join when it should have picked something else, then you’re gonna have a bad time.

Sent from my iPhone

> On May 7, 2018, at 9:59 AM, Chris Stephens <cstephens16_at_gmail.com> wrote:
>
> We have a new 5 node 12.2 RAC system that is not performing the way we want.
>
> The glaring issue is that "db file sequential read"'s are taking ~10ms. before i lob this over to the storage administrators, are there any possible areas in the clusterware/database configuration that I should investigate first? i have root access to all of the nodes. is there any information i can collect that would expedite the process of figuring out why we have such slow I/O times?
>
> slow i/o was discovered by running slob. if you don't know about that tool, you should. we all owe kevin a debt of gratitude. ;)
>
> if nothing else, i hope to learn a little more about storage than i currently know (which isn't much).
>
> thanks for any help.
>
> chris
>

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