isCOBOL ESQL is built upon JDBC, and the JDBC specification says that connections should (by default) be in 'autocommit' mode. That means that every time a modification is made (whether it be INSERT, UPDATE or DELETE), the database is commited automatically. That scenario is often what is required in plain Java, or COBOL applications.
However, inside transaction processing environments such as UniKix TPE, it makes most sense for autocommit mode to be off. That would mean that commits are not automatically done for each modification. That in turn would mean that the TPE database user exit is responsible for committing or rolling back the database at appropriate points in the CICS application lifecycle (i.e. whenever an EXEC CICS SYNCPOINT/SYNCPOINT ROLLBACK statement occurs, or at task termination).
The example user exit supplied with UniKix TPE does the correct thing.
For correct semantics with ESQL inside TPE, turn autocommit off. This is done by setting the isCOBOL property: