Tutorial 62: MSAS - Writebacks

Category: MSAS
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To browse writeback data for a cube

In the Analysis Manager tree pane, under the database that contains the cube, expand the Cubes folder.

Right-click the cube, point to Writeback Options, and then click Browse Writeback Data.

Deleting Writeback Data and Write-Disabling a Cube

The contents of a writeback table can be deleted using the Delete Writeback Data dialog box. This can be accessed by right clicking write enabled cube from analysis manager tree pane.

In the Analysis Manager tree pane, under the database that contains the cube, expand the Cubes folder.

Right-click the cube, point to Writeback Options, and then click Disable Writeback.

In the Confirm Writeback Disable dialog box, click Yes.

Converting Writeback Data to a Partition

The cube’s writeback table data can be converted into a partition. When a partition is created out of writeback data then, the cube becomes write disabled. All the unrestricted read write permissions granted are disabled. Read and read contingent permissions are not affected. This feature is only available in Enterprise edition of Microsoft SQL Server 2000.

In the Analysis Manager tree pane, under the database that contains the cube, expand the Cubes folder.

Right-click the cube, point to Writeback Options, and then click Convert to Partition.

In the Convert to Partition dialog box, in the Partition name box, type a name for the partition.

Select an aggregation design option:
To design aggregations using the Storage Design Wizard, click Design the aggregations for your partition now.

To defer aggregation design, click Design the aggregations later.
To copy the aggregation design of an existing partition, click Copy the aggregation design from an existing partition and select the partition name from the Copy from list. If in the future you might merge the new partition with another, copy the aggregation design of the other partition. Merged partitions must have the same aggregation design.

To specify a filter (WHERE clause expression) that limits the data selected from the writeback table and added to the partition, click Advanced.

To process the new partition, select the Process the partition when finished check box. Depending on the size of the writeback table, processing may take considerable time.

Writeback Timeout Property

The Client application attempts to communicate updates to a writeback table on the server. The time taken for communication is set in the Writeback timeout property. When the application attempts to writeback the changes, the PivotTable Service begins count in seconds and ends when the transaction is committed in the number of seconds specified in this property. If the time limit is reached before the changes are applied the commit fails. The client will rollback the transaction when the commit fails and the attempt to commit begins again. This property is to be set when a session is established and it cannot be changed during the session.

Actions, Drillthrough and Writebacks are extremely useful features of Analysis services. Actions allow the end user view data and act on the anlaysis of such data. Drillthrough enables users to view the details of the aggregated data presented in cubes. Writeback enables users to update the data and also view the impact of such changes on the data in the cube.

In the next lesson we will study the process of “Implementing security” in Analysis Services.

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