Can GoldenGate Replicate An Oracle Table That Contains Only CLOB Column(s)? (Doc ID 971833.1)

Oracle GoldenGate - Version 4.0.0 and later
Information in this document applies to any platform.

 

SOLUTION

Question
Can GoldenGate replicate an Oracle table that contains only CLOB columns?

Answer
To ensure Data Integrity when performing Update and Delete operations, GoldenGate requires each Source and Target Table to have a Unique Identifier. This Unique Identifier can be:

            * a Primary Key
            * a Unique Index
            * one or more columns that contain unique values and are specified with a GoldenGate KEYCOLS clause.

To make those columns available to GoldenGate, they must be logged to the Redo Log by Oracle's Supplemental Logging feature.  Oracle does not support Supplemental Logging for CLOB columns; therefore Updates and Deletes on those columns cannot be replicated by GoldenGate.

If you attempt to enable Supplemental Logging for a CLOB column, either with the GoldenGate ADD TRANDATA command or through SQL*Plus, you will receive the following errors:

          SQL> create table ggs.customers (a clob, b clob);
          GGSCI (xxx) 4> add trandata customers
          No key found for table GGS.CUSTOMERS. All columns will be logged.
          2007-05-24 10:37:57 GGS WARNING 301 WARNING: key column may exists after column A, may not be able 
          to handle row chaining.
          2007-05-24 10:37:57 GGS WARNING 301 WARNING: key column may exists after column B, may not be able 
          to handle row chaining.
          2007-05-24 10:37:57 GGS WARNING 301 Table GGS.CUSTOMERS has no valid key columns, no supplemental log group was added.
          
          SQL> alter table customers add supplemental log group customers_s (a) always;

          alter table customers add supplemental log group customers_s (a) always
           *
          ERROR at line 1:

          ORA-30569: data type of given column is not supported in a log group

          Error: ORA-30569 (ORA-30569)

          Text: data type of given column is not supported in a log group

Cause
An attempt was made to include a column with one of these Unsupported Data Types:  LONG, VARRAY, nested table, object, LOB, FILE, or REF in a Log Group.

Action
Change the Column Data Type or remove the Log Group. Then retry the operation.

其它:

https://docs.oracle.com/goldengate/c1230/gg-winux/GGHDB/understanding-whats-supported-db2-luw.htm#GUID-DB7F8E88-BAB5-404A-AA0C-2E01105F4903