FIX: SET ROWCOUNT or TOP With Partitioned View May Cause Poor Performance
This article was previously published under Q255633
This article has been archived. It is offered "as is" and will no longer be updated.
BUG #: 55537(SQLBUG_70)
If you use the SET ROWCOUNT option or TOP keyword to limit results, a SELECT on partitioned views takes longer because it introduces extra SPOOL in the query execution plan. This only happens if the view is defined on a large number of tables in the same or different database. Using the SHOWPLAN option, you can identify the extra SPOOL:
|--Table Spool |--Clustered Index Scan(OBJECT:([DATABASE1].[dbo].[TABLE1].[index_0])) |--Clustered Index . . . |--Clustered Index Scan(OBJECT:([DATABASEn].[dbo].[TABLE1].[index_0]))
Reducing the number of partitions results in CONCAT instead of SPOOL and provides better performance.
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:
254561 INF: How to Obtain Service Pack 2 for Microsoft SQL Server 7.0 and Microsoft Data Engine (MSDE) 1.0For more information, contact your primary support provider.
Article ID: 255633 - Last Review: 10/20/2013 17:47:16 - Revision: 2.1
Microsoft SQL Server 7.0 Standard Edition
- kbnosurvey kbarchive kbbug kbfix KB255633