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 from a 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