You can specify pre- and post-session SQL in the Source Qualifier transformation and the target instance when you create a mapping. When you create a Session task in the Workflow Manager you can override the SQL commands on the Mapping tab. You might want to use these commands to drop indexes on the target before the session runs, and then recreate them when the session completes.

The Integration Service runs pre-session SQL commands before it reads the source. It runs post-session SQL commands after it writes to the target.

You can use parameters and variables in SQL executed against the source and target. Use any parameter or variable type that you can define in the parameter file. You can enter a parameter or variable within the SQL statement, or you can use a parameter or variable as the command. For example, you can use a session parameter, $ParamMyPreSQL, as the source pre-session SQL command, and set $ParamMyPreSQL to the SQL statement in the parameter file.