Using XA with Oracle Rdb via DECdtm V2.0

DECdtm is a Distributed Transaction Manager which provides a two-phase commit (2PC) protocol for OpenVMS applications. Compaq Computer Corporation recently added capabilities to DECdtm which allow it to participate in or even manage transactions using the X/Open XA 2PC protocol. The benefits of this new capability are principally these:


  • A DECdtm-compliant Resource Manager (RM) such as Oracle Rdb can participate in an XA distributed transaction.
  • An XA-compliant Resource Manager (RM) such as Oracle8 i /9 i can participate in a DECdtm distributed transaction.

A presentation was given at the December 2001 Oracle Rdb Forum on this new capability and the slides for this presentation can be viewed at

Compaq is releasing the new XA interface capability as an integral part of DECdtm in OpenVMS 7.3-1 (code named Rudy). No additional licensing is required. It will be available for OpenVMS Alpha and will be ported to Itanium. Currently there is an SDK available which allows you to download and install the XA interface capabilities as a layered product. It is intended for use with OpenVMS 7.2 (Alpha only) and can be found at

DECdtm V2.0 is transparent to Oracle Rdb which simply participates in a DECdtm distributed transaction as it has for many years. DECdtm V2.0 with Oracle Rdb is supported by Oracle Rdb 7.0.6 and later and and later.