Changing Runtime Priority of a Running Query

CHANGE_CURRENT_STATEMENT_RUNTIME_PRIORITY lets you to change a query's runtime priority. You can change the runtime priority of a query that is already executing.

This function takes two arguments: 

• The query's transaction ID, obtained from the system table SESSIONS
• The desired priority, one of the following string values: HIGH, MEDIUM, or LOW

Restrictions

Superusers can change the runtime priority of any query to any priority level. The following restrictions apply to other users:

• They can only change the runtime priority of their own queries.
• They cannot raise the runtime priority of a query to a level higher than that of the resource pools.

Procedure

Changing a query's runtime priority is a two-step procedure:

1. Get the query's transaction ID by querying the system table SESSIONS. For example, the following statement returns information about all running queries:

   => SELECT transaction_id, runtime_priority, transaction_description from SESSIONS;
   

2. Run CHANGE_CURRENT_STATEMENT_RUNTIME_PRIORITY, specifying the query's transaction ID and desired runtime priority:

   => SELECT CHANGE_CURRENT_STATEMENT_RUNTIME_PRIORITY(45035996273705748, 'low')