Article ID: 245406 - View products that this article applies to.
This article was previously published under Q245406
This article has been archived. It is offered "as is" and will no longer be updated.
BUG #: 55007 (SQLBUG_70)
On large tables, a nonclustered index covering the WHERE clause is not chosen if a varchar field is specified by a LIKE clause.
When possible, replace the nonclustered index covered by the WHERE clause with a clustered index. In the example given in the MORE INFORMATION section of this article, you would change the primary key clustered index by a nonclustered index. Re-create index [BUT000~SOT] as clustered.
Microsoft has confirmed this to be a problem in SQL Server 7.0. This problem has been corrected in U.S. Service Pack 2 for Microsoft SQL Server 7.0. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
254561For more information, contact your primary support provider.
(http://support.microsoft.com/kb/254561/ )INF: How to Obtain Service Pack 2 for Microsoft SQL Server 7.0 and Microsoft Data Engine (MSDE) 1.0
The following script reproduces the problem:
Then run a query such as:
The query uses the primary key index by seeking through the CLIENT column, which has a selectivity of 1, instead of using the index BUT000~NAM, which is covering the WHERE clause.
Contact us for more help
Connect with Answer Desk for expert help.