This page will provide an overview of things to consider when using Access Views for Information Sources supporting Data Mart access based on Materialized Views.
Information Source access based on Materialized Views is not a common scenario when setting up Analysis Models. Most Information Sources needed for Analysis Models supports incremental load based on table access. The disadvantage with Materialized Views is that the IFS implementation only supports complete/full refresh.
This page only supplies some general advice for cases where Data Mart access based on Materialized Views is used. For more information, please refer to Data Mart administration and configuration.
When Data Mart access is chosen for an Information Source, it is advised to make sure that the Enabled Data Access Type is defined correctly.
This is done in the Information Source page.
Please refer to Configure Incremental Data Mart Load for more information.
Materialized Views can be viewed in the Data Mart Sources page.
This page supports manual activation as well as refresh. Activation is the step where the first Materialized View snapshot is created and this must be done for all involved Materialized Views. Even if the first as well as subsequent refresh operations will lead to a complete refresh, the activation should not be done by mistake. It is important to make sure that Materialized Views specific snapshots can be made without problems and within reasonable time. There is basically two ways of handling the activation:
In the assistant, select:
If only directly referenced or all referenced data mart sources should be used.
If statistics should be gathered; suggested.
Materialized Views that are already activate will not be affected by a new activation.
Also note that generally, if the Refresh Status is UNUSABLE but the data mart source is Active, then use the Refresh option instead of Activate. The result will be the same. The command Activate is enabled when the Refresh Status is UNUSABLE and the data mart source is not Active.
Once the activation has been finalized it is necessary to keep that Materialized Views up-to-date.
The recommended way is to set up scheduled job that will refresh all Materialized Views defined in Data Mart Refresh Category. The easiest way to do this is to create a Data Mart Refresh Category from the Information Source page by using the command Add Dm Sources to MV Refresh Category that will start an assistant that guides the user how to create a refresh category.
Once the category has been created, use the command Schedule Refresh in the Data Mart Refresh Category page to set up a schedule for regular refresh, e.g. once every day.