16.10 - CDM Considerations - Teradata Unity

Teradata Unity User Guide

Product
Teradata Unity
Release Number
16.10
Published
January 2018
Language
English (United States)
Last Update
2018-03-29
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In Unity 16.20 using CDM, the following are supported:
  • Updatable cursors or results sets
  • Writing to tables with Identity columns
    To avoid conflict between values set on different systems, CDM requires that you redefine the IDENTITY columns so they have different ranges on different systems. Replicating IDENTITY columns significantly affects performance.
CDM is not compatible with Teradata Secure Zones (Multitenancy), and does not support the following Teradata Database features. If a client application issues a request that uses any of the following features, the request fails and an error Failure 4514 - Write disallowed because it contains a non-deterministic clause appears.
Some of the following features are supported with Unity SQL multicast.
CDM cannot be used on non-deterministic requests if the request:
  • Uses a Load utilities such as FastLoad, MLoad, TPTLoad or MLoadX
  • Changes a table that uses Columnar and Column Partitioning
  • Replicates tables or requests that use data types added since DBS 13.10:
    • NUMBER
    • DERIVED PERIOD
    • ARRAY
    • JSON
  • Changes a table containing any of the following unsupported datatypes:
    • NUMBER
    • UDT with NUMBER
    • DERIVED PERIOD
    • ARRAY
    • JSON
  • Involves an XML/XQuery function call
  • Uses a Volatile table or Global temporary table
  • Uses the SQL syntax: CREATE TABLE … AS …
  • Issues a QueryGrid / SQL-H / Foreign Server request
  • Has an Update, Delete or Merge into NOPI tables
  • Involves Teradata Secure Zones (Multitenancy)
  • Writes to a temporal table via Unity unless the user has NONTEMPORAL privileges
  • Writes to a table utilizing the Teradata 16.00 1 MB ROWs feature
  • Uses Unicode pass through characters
  • Replicates rows that use the 1MB perm space feature
Workloads requiring CDM may experience both fixed and variable latency.