Settings for Specifying Whether and How to Use Joins

These settings enable the AtScale engine to define aggregates that use joins and affect how it determines whether a join is appropriate for a given aggregate.

To access these settings:

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Restriction: Your user ID must be a super user.

1. Choose Settings from the main navigation, select Engine. Use your browser Find to search for each setting.

Settings

AGGREGATES.CREATE.JOINS.ENABLED
Set to True to allow the AtScale engine to use joins when defining aggregates.

This setting must be set to True for the following three settings to have an effect.

The default value of this setting is True.

AGGREGATES.CREATE.JOINS.COMPRESSION
Specify the minimum compression ratio for any proposed join. This ratio is calculated as the cardinality of the join key to the cardinality of the grouped dimension values (i.e #(Join Key) / #(Dim Table grouped by Dim Value)). Joins for which the compression ratio is lower than this minimum will not be used.

The default is 100.

AGGREGATES.CREATE.JOINS.MAXIMUMDEPTH
Specify the maximum number of dimensions that can be traversed in a join path.

The default is 3.

AGGREGATES.CREATE.JOINS.MAXMIMUMKEYCARDINALITY
Specify the maximum cardinality that the AtScale engine will allow in join keys when the engine is determining whether to use a join in the definition of an aggregate. Higher cardinalities will cause the engine not to use a join.

As of AtScale 20201.0, the default value is 10,000,000.