Application Development Guide

Multisite Update with DB2 Connect

DB2 Connect allows you to perform a multisite update, also known as two-phase commit. A multisite update is an update of multiple databases within a single distributed unit of work (DUOW). Whether you can use this capability depends on several factors:

• Your application program must be precompiled with the CONNECT 2 and SYNCPOINT TWOPHASE options.
• If you have SNA network connections, you can use two-phase commit support provided by the sync point manager function of DB2 Connect Enterprise Edition Version 7 on AIX, OS/2, and Windows NT. This enables the following host database servers to participate in a distributed unit of work:
  • DB2 for AS/400 Version 3.1 or later
  • DB2 for MVS/ESA Version 3.1 or later
  • DB2 for OS/390 Version 5.1 or later
  • DB2 for VM & VSE Version V5.1 or later.

  The above is true for native DB2 UDB applications and applications coordinated by an external Transaction Processing (TP) Monitor such as IBM TXSeries, CICS for Open Systems, BEA Tuxedo, Encina Monitor, and Microsoft Transaction Server.

  Note:

  For more information on BEA Tuxedo, refer to the DB2 Connect User's Guide.

• If you have TCP/IP network connections, then a DB2 for OS/390 V5.1 or later server can participate in a distributed unit of work. If the application is controlled by a Transaction Processing Monitor such as IBM TXSeries, CICS for Open Systems, Encina Monitor, or Microsoft Transaction Server, then you must use the sync point manager.

  If a common DB2 Connect Enterprise Edition server is used by both native DB2 applications and TP monitor applications to access host data over TCP/IP connections then the sync point manager must be used.

  If a single DB2 Connect Enterprise Edition server is used to access host data using both SNA and TCP/IP network protocols and two phase commit is required, then the sync point manager must be used. This is true for both DB2 applications and TP monitor applications.