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Set the Slice property on partitions with ROLAP storage mode or with proactive caching settings that allow entering ROLAP mode

This rule analyzes database partitions to determine which partition do not have a slice defined but meet one of the following conditions:

  • The partition is set to ROLAP.

  • The partition is set to MOLAP, but proactive caching has been enabled and is configured such that the OnlineMode property is set to Immediate. (Such partitions are treated as ROLAP during the construction of the MOLAP cache.)

Best Practices Recommendations

For best performance, you should typically set the Slice property for partitions that use the ROLAP storage mode or have proactive caching settings that enable the ROLAP mode to be entered.

For ROLAP partitions, a slice should be specified or the partition will always have to be queried for what type of data the partition contains. For example, suppose one partition contains data for only 2002 and one partition contains data for only 2003. The Slice property for each partition reflects this information. A query asks for sales data for 2003. By referring to the Slice property, the server knows which partition contains the 2003 sales data without having to query the partition for the data that it contains.

For MOLAP partitions, you do not have to specify the slice because the server will be able to determine the relevant partitions after the data has been processed. However, when you use proactive caching, you should specify the slice manually because the partition might be treated as ROLAP during the construction of the MOLAP cache.

Note

Make sure that the slice specified for a MOLAP partition is consistent with the data in the partition. If the slice is not consistent with the data, the server will raise an error when it processes the data.

To set the Slice property

  1. In Business Intelligence Development Studio, on the Partitions tab of the Cube Editor, select the partition.

  2. In the Properties window, for the Slice property, click the text box, and then click the ellipsis button (...).

  3. In the Partition Slice dialog box, type a Multidimensional Expressions (MDX) expression to specify the member on which you want to slice.

    To slice on multiple hierarchies, enter a tuple that contains the members on which you want to slice.

For More Information

For more information about how to configure proactive caching, see Proactive Caching in SQL Server Books Online.

For more information about performance issues related to proactive caching, see the section, "Near real-time data refreshes," in the SQL Server 2005 Analysis Services Performance Guide.