Caution It is possible to create partitioned cubes that contain incorrect data. For more information, see Partitions and its subtopics in the Administrator’s Guide.
This dialog box enables you to:
This dialog box is displayed when you click Advanced in the Convert to Partition dialog box or the last step of the Partition wizard.
Type a filter expression (WHERE clause expression of an SQL SELECT statement) to limit the data used to create the partition. Do not type WHERE.
Important One use of filter expressions is to ensure that all partitions in a cube contain mutually exclusive data. Otherwise, the cube will contain duplicate and therefore inaccurate data. When you write a filter expression for this purpose, ensure that it excludes data already in the cube’s partitions.
For example, a cube contains three partitions, one for each year 1995, 1996, and 1997. You are creating a new partition for 1998 from the same table that supplies the data for the other partitions. The name of the column that contains years is the_year. You must use the following filter expression:
"the_year"=1998
Another example (alphanumeric data):
"the_month"='January'
Whenever necessary to avoid ambiguity, use a qualified expression. For example, if a column name appears in multiple tables, include the table name in the expression:
"time"."the_month"='January'
The SELECT statement used to retrieve records for the creation of the partition is generated automatically. The filter expression is connected with an AND to the automatically-generated part of the WHERE clause. Therefore, if you specify multiple filter expressions, enclose them all in a pair of parentheses, for example:
("the_year"=1998 OR "the_year"=1999)
Filters consist of one or more expressions using columns in the fact table. A filter can also contain columns in dimension tables if they are included in a nested SELECT statement and the underlying database supports nested SELECT statements. For more information, see Filters.
The filter expression acts as a pass-through statement, and its syntax is not checked until you process the partition. If the syntax is incorrect, processing fails.
Specify the prefix used for the partition’s aggregation names.