Run APPLY Table Operator | Open Analytics Framework | VantageCloud Lake - Running APPLY Table Operator - Teradata Vantage

The APPLY table operator invokes all AMPs on the compute cluster to start processes that runs the program specified by the APPLY_COMMAND clause. A PARTITION BY clause invokes a new process per partition so that your program only has to be scoped to processing a partition. If multiple partitions are processed by the same AMP, multiple processes are started by the same AMP to process each partition one at a time.

You can only run APPLY table operator queries in the presence of a user environment. The user environment is a concept about a scoped space controlled by the user to run the APPLY table operator in it, so no other operations are allowed on other environments that belong to other users.

Before running the APPLY table operator, you need to establish a connection to a target VantageCloud Lake system with your credentials and an authentication token. You typically receive this information from your system administrator.

The following is an example of APPLY_COMMAND invoking the Python interpreter to run a user script in the 'myscript.py' file within the user environment called 'myenvironment':

SELECT * FROM TD_SYSFNLIB.APPLY
(
   ON intab
   RETURNS (col1 int, col2 varchar(20))
   USING
   STYLE('csv')
   APPLY_COMMAND('python3 myscript.py')
   ENVIRONMENT ('myenvironment')
) as dt;