What Are Supported Query Features?

The Oracle Analytics query engine uses the specified query features settings to determine how to query the data source. The supported query features are automatically populated with values appropriate for your semantic model's data source.

Query features are the SQL expressions, statements, function, operations, and other features that you can run against the data source such as a query that uses an ISDESCENDANT statement. Operations such as ADD or SQRT (square root) operations are supported.

When a supported query feature is selected or a value is specified, the data source supports the feature and the Oracle Analytics query engine pushes the function or calculation to the data source for improved performance.

When a supported query feature is deselected or no value is specified, then it isn't supported in the data source and the calculation or processing is performed in the Oracle Analytics query engine.

In most cases, you should keep the default selections and values. If you enable or change query features that the data source doesn't support, your query may return errors and unexpected results. If you disable supported SQL features, the server could issue less efficient SQL to the data source. Before you change any of the defaults, confirm that the query feature is supported by the data source.

See Modify a Database's Supported Query Features.

These are some reasons why you would update a database's query feature settings:

  • If you're upgrading to a newer version of a data source. In this case, you can tailor the query features for the data source to see if the updated feature is reflected in the Oracle Analytics query engine defaults.

  • If a data source supports a particular feature such as left outer join queries but you want to prohibit the Oracle Analytics query engine from sending such queries to a particular data source.

  • If you have federated data sources that run functions differently. In this case, you can disable the appropriate functions so that Oracle Analytics query engine performs calculations consistently and produce correct query results.

  • If you're troubleshooting a query or other operation that isn't working as expected.