Defining Aggregates Yourself

You can define your own aggregates for use cases that fall outside of those covered by system-defined aggregates.

Prerequisites

Before defining aggregates for your models, you should familiarize yourself with the following sections:

• When to Define Your Own Aggregate Tables

• Partitioned User-Defined Aggregates

• About Incremental Rebuilds

• If your aggregate definition will use one or more joins to dimensional datasets and the aggregate is allowed to be built with incremental builds, follow these steps before creating the aggregate:

  1. Read the section Incremental rebuilds of aggregates that use joins in to ensure that you are aware of the special considerations for such aggregates.
  2. In Design Center, edit the fact dataset's underlying SML to include the incremental property. For more information, see About Incremental Rebuilds and the AtScale SML Object Documentation on GitHub.

• If you want instances of your aggregate definition to be partitioned:

  • Verify that the TABLES.CREATE.PARTITIONS.ENABLED and AGGREGATES.CREATE.PARTITION.USERDEFINEDAGGREGATE.ENABLED engine settings are both enabled, as described in Engine Settings for User-Defined Aggregates Only.
  • Set a partition key for the aggregate definition. For instructions, see Partitioned User-Defined Aggregates.

Defining aggregates for a model

To define aggregates for a model, you must edit the model file's underlying SML to include the aggregates proprty. For more information, see the AtScale SML Object Documentation on GitHub.

What to do next

The user-defined aggregate table is created the next time the model is deployed. You can check the status of the aggregate creation on the Aggregates page.