In order to preserve transactional atomicity, database-side JDBC routines that use nested connections have the following limitations. Nested connectionslimitations of

• Can issue a commit or rollback only within a procedure (not a function).
• Cannot change the auto-commit connection attribute.
• Cannot modify the data in a table used by the parent statement that called the routine, using INSERT, UPDATE, or DELETE. For example, if a SELECT statement using the T table calls the changeTables procedure, changeTables cannot modify data in the T table.
• Cannot drop a table used by the statement that called the routine.
• Cannot be in a class whose static initializer executes DDL statements.

In addition, the Connection object that represents the nested connection always has its auto-commit mode set to false.