RE: Select parallel understanding

  • From: "Christian Antognini" <Christian.Antognini@xxxxxxxxxxxx>
  • To: "Taral Desai" <taral.desai@xxxxxxxxx>
  • Date: Tue, 24 Nov 2009 08:54:25 +0100

Hi Taral

> Now if you can see above that for _01 & _03 there is little or very less
> blocks in buffer. I was expecting that _04 would also have same thing as
> it's running in parallel.

Did you gather the object statistics before running the test? 
If not, dynamic sampling would do its job and, as a result, some blocks would 
be loaded in the buffer cache.

> So, if i am not understanding wrong then insert had worked with direct load
> but not select ?

Mhmm... not sure to understand what do you mean here. In fact, direct load is 
not relevant for select statements.

Chris Antognini

Troubleshooting Oracle Performance, Apress 2008

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