Sizing SGA
From: Niall Litchfield <niall.litchfield_at_gmail.com>
Date: Thu, 6 Oct 2016 14:51:59 +0100
Message-ID: <CABe10sbxzbg=-V4v+v0cXoxYvqd=0NTG-RmBissBT2iNSep42g_at_mail.gmail.com>
A colleague asked me a question yesterday to which I don't really have a good answer; so I thought I'd crowdsource it.
Date: Thu, 6 Oct 2016 14:51:59 +0100
Message-ID: <CABe10sbxzbg=-V4v+v0cXoxYvqd=0NTG-RmBissBT2iNSep42g_at_mail.gmail.com>
A colleague asked me a question yesterday to which I don't really have a good answer; so I thought I'd crowdsource it.
Given a RAC database of N instances each with an SGA of M gb in size. When changing the instance count N how, if at all, do you modify the value of M? What metrics do you look at, and what is the rationale behind that.
I'm aware that "let it run for a while and use the memory advisors" is an approach - I can't say I have a lot of confidence in the memory advisors from past experience.
--
Niall Litchfield
Oracle DBA
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Received on Thu Oct 06 2016 - 15:51:59 CEST