Microsoft KB Archive/241371

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PRB: Cube Design and Processing Problems Working with GUID Data Type

Article ID: 241371

Article Last Modified on 10/31/2003



APPLIES TO

  • Microsoft SQL Server OLAP Services
  • Microsoft SQL Server 2000 Standard Edition



This article was previously published under Q241371

BUG #: 3262 (plato7x)

SYMPTOMS

SQL Server 7.0 or later provides a uniqueidentifier data type that stores 16-byte binary values, which operate as Globally Unique Identification Numbers (Uniqueidentifier or GUIDs). We do not recommend use of the SQL Server 7.0 (or later) uniqueidentifier data type columns when you work with OLAP Services. Several problems have been observed in the behavior of the OLAP Manager when dealing with Uniqueidentifier (GUID) data type columns. These problems are:

  • If a table join is made between a fact and a dimension table, based on a GUID data type column, the dimension wizard automatically joins these columns as long as the column names are the same and the schema is not a snow flake. However, if the schema is a snow flake and the dimension tables are joined by uniqueidentifier columns, then it is not possible to join the dimension tables and a message like the following appears:

    MsgBox Title: Join Failed
    prodclassGuid and prodclassGuid have incompatible data types.
    prodclassGuid: Char
    prodclassGuid: Char

  • If a user deletes a join between uniqueidentifier columns (of a fact and dimension table) from within the OLAP Manager cube editor and then tries to manually join uniqueidentifier columns, a message like the following appears:

    MsgBox Title: Join Failed
    custGuid and custGuid have incompatible data types.

    custGuid: Char
    custGuid: Char

  • Cube processing may fail if a dimension level is based on a uniqueidentifier data type column.


WORKAROUND

The workaround is to create a view within SQL Server that converts the uniqueidentifier data type column(s) to a char(n) or varchar(n) data type. Create one view for each dimension or fact table and then reference these views for creating dimensions or measures within the OLAP Manager or Decision Support Object (DSO) program.

MORE INFORMATION

Strings and numbers are the only data types that OLAP Services support. By design, other data types, like the SQL Server uniqueidentifier are not supported in OLAP Services.

Keywords: kbprb KB241371