Distributed Transaction Management (DTM)

Adaptive Serve automatically prevents SQL commands that are intended to execute inside a distributed transaction from executing outside it.

A distributed, or external, transaction is managed by an external transaction coordinator, such as XA Transaction Manager (TM).

In versions of Adaptive Server earlier than 15.0.3, user applications determined whether an external transaction was rolled back while executing DML commands. If Adaptive Server implicitly aborted an external transaction without the application’s knowledge, DML commands that would normally run inside this transaction might instead be executed inside an implicit transaction started by Adaptive Server. This behavior could result in inconsistent business data.

In versions 15.0.3 and later, Adaptive Server does not allow any DML commands to be executed on the connection attached to the external transaction until the transaction manager sends a detach request. The detach request indicates the end of a batch of commands intended for the external transaction.

In versions 15.0.3 and later, Adaptive Serve automatically prevents SQL commands that are intended to execute inside a distributed transaction from executing outside it. The user application no longer has to check the global variable before every command; when a transaction is implicitly aborted, an error message (3953) appears, saying “Cannot execute the command because the external transaction has been rolled back.” This message disappears when a detach transaction command is issued.