Re: Optimization question: Unrolling subquery into IN clause

From: Ind-dba <>
Date: Fri, 23 Oct 2009 01:43:36 -0700 (PDT)
Message-ID: <>

On Oct 23, 12:42 pm, Wolfram Roesler <> wrote:
> Randolf Geist <> wrote
> > So if the TAB2.COL3 column is skewed and the value "L" is only showing
> > up 20 times, then you need to tell the optimizer about that and add a
> > histogram on this column, if it's not there already.
> That was the reason of the problem. I fixed the histograms on the
> column in question, and now my query finishes in less than a second.
> For the version with bind variables, this means a speed-up by a
> factor of 1000.
> The problem is thus completely understood and solved.
> Thanks to all who helped!
> Best regards
> W. Rösler

Great! that your issue is fixed.

But you earlier mentioned that you dont use histograms: "There are no histograms." Received on Fri Oct 23 2009 - 03:43:36 CDT

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