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Last tested: Feb 20, 2020
In order to use PDTs, your database will need to be configured to allow Looker to build and maintain tables on the database.
- Main database connection must support writes. Read-only databases cannot use PDTs*
- A scratch schema that the Looker database user has adequate permissions to write to. Instructions for setting this up here: https://docs.looker.com/setup-and-management/database-config
- The connection in Admin > Connections must have the Persistent Derived Tables enabled. This can be enabled here: https://docs.looker.com/admin-options/database/pdts
Once you enable PDTs for your connection, you’ll notice that there is a “PDT Override” column. In the PDT Override column, you can enter separate JDBC parameters (host, port, database, username, password, schema, and additional parameters) that are specific to PDT processes.
More information as well as use cases for configuring separate login credentials for PDT processes located in our PDT Override documentation.
*We have seen a few cases in which users have used the PDT Override feature to configure a separate, read-only database for use with PDTs. This use case is not what the override feature is meant for, but may nonetheless 'just work' in some cases.