Currently supported connection properties:
A connection-level property to customize query behavior. Under JDBC, these correspond directly to connection properties passed to the DriverManager.
Under ODBC, these correspond to properties in the connection string.
dataset_project_id: represents the default project for datasets that are used in the query. Setting the system variable @@dataset_project_id achieves the same behavior.
time_zone: represents the default timezone used to run the query.
session_id: associates the query with a given session.
query_label: associates the query with a given job label. If set, all subsequent queries in a script or session will have this label. For the format in which a you can specify a query label, see labels in the JobConfiguration resource type. Additional properties are allowed, but ignored. Specifying multiple connection properties with the same key returns an error.