INF: Advantages of Using Numeric Dimension Keys (304155)


The information in this article applies to:

  • Microsoft SQL Server OLAP Services 7.0
  • Microsoft SQL Server 2000 Analysis Services
This article was previously published under Q304155

SUMMARY

The Key Data Type property of a dimension indicates the data type of the columns that store member keys in aggregations. Member keys are copied from the column specified in the Member Key Column property. This article explains some of the advantages of using numeric keys as opposed to character keys.

MORE INFORMATION

The type of data indicated by the Key Data Type property affects processing time, the size of the dimension structure and memory usage. If the Key Data Type property is set to a character data type, processing requires string comparisons, which is more time consuming. Conversely, if the Key Data Type property is set to a numeric data type, processing involves simpler number comparisons resulting in faster processing.

Numeric values have the same length, which simplifies and reduces storage requirements. String values can be of variable lengths and are stored differently than numeric values, which results in an additional level of indirection and greater storage requirements. Memory requirements for string values are also higher than for numeric values, which results in larger dimensions and greater memory usage.
Modification Type:MinorLast Reviewed:7/15/2004
Keywords:kbinfo KB304155
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