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On Thu, Jul 28, 2016 at 11:09 AM, Birgitta Hauser <Hauser@xxxxxxxxxxxxxxx>
wrote:
1. What happens if you add an Order By to your SELECT statement with the
range?
Still a full table scan
2. What happens if you additionally create a derived index over the
relative record no?
A full table scan w/o ORDER BY, Index probe with ORDER BY, returning in
61ms.
Interestingly, the "estimated number of rows" coming out of the table scan
is 745,428.
Which is then feed into an "AND" operation...with 745,429 rows coming out
of that into the final select.
I tried adding an OPTIMIZE FOR 11 ROWS, that didn't have an effect.
Also tried FETCH FIRST 11 ROWS ONLY..that still shows the table scan with
745,428 rows, but it returns in 241ms instead of 27.4s
Charles
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