FIX: Query Performance Deteriorates After an Incremental Update to a Non-Changing Dimension (328873)

SYMPTOMS

After you perform an incremental update on a non-changing dimension, the performance of queries on cubes that contain that dimension is noticeably slower than before the incremental update. The contents of the data folder for cubes that contain the dimension are missing the <Cube name>.<Number>.Fact.Map and <Cube name>.<Number>.Agg.Rigid.Map files, where <Cube name> is the name of the cube and <Number> is the order in which the dimension appears in the Cube Editor for this cube.

CAUSE

To understand the cause of this problem it is important to first understand the behavior of changing dimensions.

When an incremental update to a changing dimension occurs, the aggregations and indexes for that dimension may no longer be valid, because members in a changing dimension can move positions in the dimensional hierarchy. As a result, Analysis Server deletes the existing aggregations and indexes, and then rebuilds these in the background.

Before this update, Analysis Server incorrectly removed the indexes for a non-changing dimension when an incremental was performed on that dimension. The missing index files are rebuilt in the background; however, until the new index files are available, all queries must scan the OLAP data when they try to resolve queries that involve the affected dimension.

RESOLUTION

To resolve this problem, obtain the latest service pack for Microsoft SQL Server 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

290211 INF: How To Obtain the Latest SQL Server 2000 Service Pack

NOTE: The following hotfix was created before the release of Microsoft SQL Server 2000 Service Pack 3.

The English version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

   Date        Time    Version         Size              File name
   -------------------------------------------------------------------

   8/30/2002   20:02       8.0.681.0   1,782,340 bytes   Msmdsrv.exe
   4/18/2001   01:23   2000.80.382.0     815,676 bytes   Sqldata.dll
   8/30/2002   20:07   2000.80.534.0     590,396 bytes   Sqlsort.dll