Can not execute DDL in SSIS.

Hi,

I'd like to drop some indexed inside an SSIS SQL Task, but this failed with the following error: "Connection is readonly, only select statements are allowed.". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.

I've checked the connection, which should be fine because ddl can run in pgadmin or other ODBC query tools.
In the SSIS Task, statements like 'select'/ 'refresh' work as expected, which I guess it does not change the database schema. But create/drop would fail.
I've seen some posts that say we sould check if the odbc.ini is set to readonly. But I do not know which odbc.ini it refers to.

Any idea how to solve this?

Many thanks!