Re: Informal poll: What's your avg redo write time?

From: Jeremy Schneider <>
Date: Thu, 19 Feb 2015 16:29:10 -0500
Message-ID: <>

if you're troubleshooting a LGWR issue, you might see if this script gives you some additional useful info - it helped me a bunch with some LGWR related troubleshooting last year.

i haven't looked at kyle's script to see what exactly it's doing - but assuming it's just showing the time for write calls to the storage, then my take would be that <1ms shouldn't be problematic on a typical system. timings are going to depend greatly on what sort of storage people are on. what kind of storage are you on?



On Thu, Feb 19, 2015 at 4:10 PM, Rich Jesse
<> wrote:

> Hey all,
> In on AIX 7.1, I'm tracing down an issue on an SR and stumbled into
> the world of LGWR. It's causing blocking locks (falsely being reported, I
> believe) when stressed, so I'm looking at LGWR performance.
> Using Kyle Hailey's average log write time query at the bottom of -- NOTE:
> my average is about 0.52ms with 90% of all between 0.4ms and 0.6ms, and
> another 8.4% at 0.7ms.
> Knowing that there's over-committing going on, I'm thinking that 0.52ms
> isn't my issue, but what are other folks getting?
> TIA!
> Rich
> p.s. Testing HTML formatting -- apologies if this message doesn't look like
> it should!
Received on Thu Feb 19 2015 - 22:29:10 CET

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