Define 'Rigid' attribute relationships when possible

Summary

Analysis Services allows for two types of relationships to be defined between related attributes in a dimenson.  Flexible relationships are those which may change over time, while Rigid relationships are those which are not expected to change.  An example of a flexible relationship would be CustomerID and Customer City, because customers often move, the city attribute value could change as part of a dimension update. Thus, any aggregations at the customer city level or above may no longer be valid after a dimension update, and requires that the aggregations be rebuilt. An example of a rigid relationship would be Calendar Date and Calendar Year. Because a date is not expected to move, a dimension update for a rigid relationship will not invalidate an aggregation that contains only attributes where the relationship is rigid. Analysis Services is optimized to improve performance of dimensions where rigid relationships are defined.  As a result, rigid relationships should be used where possible.

More Information

For more information about the products or tools that automatically check for this condition on your instance of SQL Server and on the versions of the SQL Server product, see the following table:

Rule softwareRule titleRule descriptionProduct versions against which the rule is evaluated 
SQL Server 2008 R2 Best Practice Analyzer (SQL Server 2008 R2 BPA)
Define attribute relationships as 'Rigid' where appropriate.

The SQL Server 2008 R2 Best Practice Analyzer (SQL Server 2008 R2 BPA) provides a rule to detect dimension relationship types of attributes that are involved in a hierarchy. If you run the BPA tool and get the warning message "Define attribute relationships as 'Rigid' where possible", you should examine all dimension attribute relationships and set the relationship type to 'Rigid' where possible. To determine the database, hierarchy, and dimension that triggered the BPA rule, change the Report Type from 'Results' to 'Collected Data' and expand the "Define_attribute_relationships_as_Rigid_where_possible" node.SQL Server 2008
SQL Server 2008 R2



SQL Server 2012 Best Practice Analyzer (SQL Server 2012 BPA)

Define attribute relationships as 'Rigid' where appropriate.

The SQL Server 2012 Best Practice Analyzer (SQL Server 2012 BPA) provides a rule to detect dimension relationship types of attributes that are involved in a hierarchy. If you run the BPA tool and get the warning message "Define attribute relationships as 'Rigid' where possible", you should examine all dimension attribute relationships and set the relationship type to 'Rigid' where possible. To determine the database, hierarchy, and dimension that triggered the BPA rule, change the Report Type from 'Results' to 'Collected Data' and expand the "Define_attribute_relationships_as_Rigid_where_possible" node.SQL Server 2012 







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आलेख ID: 2027468 - पिछली समीक्षा: 02/04/2012 - संशोधन: 1

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