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Cube Partitioning

Partitioning is a method of physically storing the measures in a cube. It improves the performance of large measures in the following ways:

You can partition a cube on one or more levels of a cube dimension.

Using the Default Partitioning Strategy

New cubes are partitioned by default on the second highest level of each hierarchy in the time dimension. If the cube does not have a time dimension, then the dimension with the most hierarchies is used for partitioning.

For example, if a time dimension has levels for day, week, quarter, and year, then by default all cubes dimensioned by time have a partition for each quarter.

Creating and Dropping Partitions

The OLAP engine automatically creates and drops partitions during the data loads, as members are added and deleted from the partitioning dimension. A data refresh typically creates new time periods and deletes old ones. For example, whenever a Calendar Quarter value is loaded into the Time dimension, a corresponding partition is added to the cube. Whenever a Calendar Quarter value is deleted from the Time dimension, the corresponding empty partition is deleted from the cube.

Choosing a Dimension for Partitioning

A Time dimension is typically used for partitioning for life-cycle management considerations. Old time periods are dropped as a unit and new time periods are added as a new partition. Moreover, the hierarchy is completely balanced, with the same number of children for each aggregate value at all levels.

When life-cycle maintenance is not a factor, you may choose the most dense dimension for partitioning. The most dense dimension is frequently the one with the fewest members.