Re: many "or" operation make system choose incorrect index

lsllcm (lsllcm@xxxxxxxxx) writes:
Could you provide the test step of 63 value

I am sorry, but I don't have anything canned that I easily can share.
I did this observation while working with my article on arrays and
list in SQL Server, for which I ran a bunch of performance tests. The
tests are described on
http://www.sommarskog.se/arrays-in-sql-perftest.html, but all parts for
the test is not available for download. (The test data is too big to
warrant that.)

But you could try running queries like

SELECT * FROM [Order Details] WHERE ProductID IN (.....)

in the Northgale database, which is another test database of mine. You
find it at http://www.sommarskog.se/dyn-search.html#Northgale. I cannot
promise that you will actually see this 63-value limit. Who knows, the
optimizer may use some metric to determine when to set the limit.



--
Erland Sommarskog, SQL Server MVP, esquel@xxxxxxxxxxxxx

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx
.

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