MSAS - Introduction and Managing Partitions Page - 2

Creating Partitions

Every cube must contain at least one default partition. The partition is created when the cube is created. The Partition Wizard can be used to create additional partitions. The partition can use the same data source or derive its data from a different data sources.

When the same data source is used and the same schema is used, the user can specify the portions of the Cube’s data that is to be allocated to the partition. This can be done in two ways. Different fact tables in the data source can be used for different partitions. The same fact table can be used by multiple partitions with the data in it filtered in different ways.

Benefits of creating partitions to cubes are as below

1. Different partitions of a cube can have different storage modes

2. Partitions can be processed independently of cubes

3. A cube can contain several partitions.

4. Each partition can have different data sources

5. The data sources can be on different physical locations or on the same location

6. The partitions can be distributed across servers for use of end users.

The only precautions that needs to be taken while creating partitions is that each partition must contain unique data. Analysis server provides three methods of ensuring that

1. Create separate fact tables for each partition

2. Specify a filter to restrict rows from a fact table

3. Specify a data slice, a single member of the dimension for a partition.

Working with the Partition Wizard

Expand the Cube folder under the database in which you want to create the partition for a cube. Right click Partitions folder and click on New Partition. This starts the Partition Wizard

Click Next and the user is prompted to specify the data source and the fact table for the partition. The default data source for the Sales cube is the sales_fact_1998 and the data source is FoodMart2000 database. This can be changed by clicking the change button. Click the Change Button. The list of fact tables is displayed.

Let us say we want a partition that will give us details of sales in 1997. Let us select sales_fact_1997 as the fact table from the data source FoodMart 2000 database. Now we are prompted to select the data slice. A data slice is a subset of a cube that is stored in the partition.

The user will have to pick a dimension from the Dimension box and a member from the member’s box. In the screen shot below the Time dimension has been selected and the1997 member has been selected.

The type of partition is selected next.

When the user tries to set the partition as “remote” type and he is not a domain user, he gets the following message: