Dataset settings

A dataset works with sources in direct access mode: DataLens executes all data queries on the source side. Dataset settings determine how the dataset uses the source data.

Connecting multiple tables

If multiple tables are available in the data source, you can merge them using the JOIN operator.
When the tables are joined, a link is created between them. When you create a link, you specify the fields from the source table and merged table.

You can use the following types of JOIN operators:

Default filters for new charts

In a dataset, you can create a default filter. It will be applied to any new chart created from data in the current dataset.

Note

  • You can create a filter for an individual chart in the chart settings.
  • Default filters are not applied to data in the dataset preview area.

Default filters for new charts will enable you:

  • To reduce the amount of data requested from a source when building a chart.
  • To add customized filters to new charts created from data in the same dataset.

Executing SQL queries in datasets

You can define a dataset data source using ad-hoc SQL queries over database connections. When a data source is accessed, a query code executes as a subquery. For more information about using SQL queries in a dataset, see Describing a dataset via a source SQL query.
When using SQL queries in datasets, we recommend:

  • Restricting the user specified in the connection to read-only access.
  • Assigning users that should not have ad-hoc query privileges Execute access to the connection and the associated datasets.

You can enable or disable the use of subqueries as a source when creating or editing a connection.

See also