When using subqueries that could make a conditional query false, regardless of the contents of any rows from its FROM clause, Presto initiator queries can get stuck running continuously. Disabling the dynamic filtering can help avoid problems when using subqueries.
Example query that can be problematic when enable_dynamic_filtering is not disabled:
select * from remote_table where col1 = (select null);
- [Optional] To avoid any risk of queries getting stuck, Teradata recommends doing one of the following if you anticipate using subqueries that could trivialize a WHERE clause:
- Set the session property enable_dynamic_filtering to false
- Add the following line to the Presto config.properties file: