This type of transaction only affects a single database through a single connection. A transaction is started by IIapi_query() when the qy_tranHandle parameter is NULL. The transaction is committed using IIapi_commit() or rolled back using IIapi_rollback().

This type of transaction uses the two-phase commit mechanism to ensure that committal of a distributed transaction occurs in all participating databases through multiple connections.

Distributed transactions are identified by a transaction ID handle returned by IIapi_registerXID(). This handle is used to start transactions on each participating connection by being passed as the qy_tranHandle value when calling IIapi_query(). The transaction ends by calling IIapi_prepareCommit() for each connection followed by IIapi_commit() or IIapi_rollback(). The transaction ID handle is freed by calling IIapi_releaseXID().

This type of transaction causes each individual query to be automatically committed when complete. If a cursor is opened, the commit occurs when the cursor is closed.

Autocommit transactions are started by IIapi_autoCommit() using the connection handle as input. An autocommit transaction ends by calling IIapi_autoCommit() with the autocommit transaction handle as input.

The XA transaction specification is a standardized interface for a distributed transaction processing system. This type of transaction uses a two-phase commit mechanism to ensure that committal of a distributed transaction occurs in all participating databases through multiple connections.

XA transactions are identified by an XA transaction ID. An XA transaction branch is started and associated with a particular connection by calling IIapi_xaStart(). The association is dropped by calling IIapi_xaEnd().