From: wbreidbach <wolfgang.breidb...@bv-zahlungssysteme.de>
Date: Wed, 21 Nov 2007 00:48:46 -0800 (PST)
Local: Wed, Nov 21 2007 3:48 am
Subject: Re: Discrepency between SQL/MP Explain plan, actual sequence of IOs
On 21 Nov., 09:42, wbreidbach <wolfgang.breidb...@bv-
zahlungssysteme.de> wrote:Hi again,
> On 20 Nov., 19:34, "Brian Ray" <be_...@sbcglobal.net> wrote:
> > Working on a Pathway server that does the ole' "grab a screen's worth of
> > - Operation 1) Scan TABLE1 via the aforementioned purpose-built index.
> > - Operation 2) Scan TABLE2 via one of its indexes containing the one column
> > - Operation 2.1) Hash join the result to the result of Operation 1.
> > And hooray, no sorts required. In this dev pathway our datasets are pretty
> > So then it's just a few dozen fetches until we hit end of cursor or fill up
> > Now Measure was showing some unusually high RECORDS USED and RECORDS
> > - Cursor open: A block's worth (?) of *TABLE2's* rows accessed, and a few
> > - Each fetch: 1 row accessed and used from *TABLE1*, none for TABLE2.
> > Which seems like the exact opposite of the strategy that the Explain plan
> > And as mentioned, I'm confused why all the SQLSTMT's records accessed, or at
> > Thanks,
> > Brian Ray
> Hi Brian,
> perhaps you should use Measure to check this. Just do an "ADD SQLSTMT
> - Zitierten Text anzeigen -
sorry, hit the "send button" too early, you already did what I
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