Which parameter is used in a LookML model file to specify the connection that the model should use?

In LookML, the "connection" parameter is crucial because it explicitly defines the database connection that the model will utilize. A model is essentially a layer where you define how to access and analyze data, and specifying the connection ensures that Looker knows which database to query from. This is essential for the proper functioning of the Looker reports and dashboards that rely on the data from the specified database.

The connection parameter sets the foundation for the model by linking it to a database configuration defined in the Looker instance. This enables Looker to execute SQL queries against the correct data warehouse or database, thereby facilitating accurate data retrieval and analysis.

Other parameters like database and host serve different roles. The database might refer to the specific database name within a broader connection, while host relates to the server hostname but doesn’t directly establish which connection should be used in the context of a LookML model. The link parameter is not used in this capacity within LookML and does not provide functionality related to database connections.