Change Data Multicast (CDM) | Teradata Business Continuity Manager - Change Data Multicast (CDM) - Teradata Business Continuity Manager

Teradata® Business Continuity Manager User Guide - 2.02
Deployment
VantageCloud
VantageCore
Edition
VMware
Enterprise
IntelliFlex
Product
Teradata Business Continuity Manager
Release Number
2.02
Publication Date
March 2026
Content Type
User Guide
Publication ID
B035-2550-125K
ft:locale
en-US
ft:lastEdition
2026-03-19
dita:mapPath
yae1762370477731.ditamap
dita:ditavalPath
ft:empty
ft:sourceId
dita
dita:id
otc1639627713801
Product Category
Analytical Ecosystem

CDM is a method to replicate changes between multiple systems. When enabled, CDM replicates SQL changes that are non-deterministic and can produce different results if run in parallel on different systems. CDM sends a non-deterministic SQL to the active system and then captures all the resulting data changes. It then multicasts those data changes to the standby systems. This allows Business Continuity Manager to replicate changes that involve non-deterministic functions like RANDOM and SAMPLE and writes to tables that include IDENTITY columns.

The replication of IDENTITY columns adversely affects performance. CDM requires that you redefine IDENTITY columns, so they have different ranges on different systems.
Business Continuity Manager uses CDM across managed systems to keep non-deterministic objects and triggers synchronized. Non-deterministic objects and triggers include:
  • Identity Columns
  • Dynamic SQL in Stored Procedures
  • Non-deterministic ordering or sampling (that is, Sample, TOP, ROWNUMBER)
  • Analytic functions

When non-deterministic objects or triggers are identified, Business Continuity Manager processes the action on the active Teradata system, then uses CDM to send and override the values on the standby system.