MDM 321 – SAP Netweaver Master Data Management

Symptom
Changes are being made to repository but but the changes are not
being reflected in the Change Tracker. There appear to be no records in table: a2i_CM_History.
Reason and Prerequisites
This could happen due to any of the following reasons:
1. The Change Tracking was not enabled for the specific table and/or for the specific update action.
2. The SQL database or the Oracle schema of the a2i_CM_history table that is being looked into, is not the one into which the changes were written.
Users always expect that the name of the database for change tracking is <repository name>_z000, but there are cases in which this database is created as <repository name>_z001 (or so) and the changes are actually written into this one.
The cases in which it could happen are the following:
2.1 The names under which an MDM repository is created in DBMS are indeed <repository_name>_m000 and <repository_name>_z000 respectively.
But when the repository name is too long to meet the DBMS naming rules,
the name in DBMS will be truncated to meet the maximum length enabled
by the DBMS. Now if you will create another repository with the same
long name+one additional character, MDM will try to store it in DBMS
with the truncated name, but since after truncation the second name
will be identical to the one already exist in the DBMS, it will be given the suffix of _m001 and _z001 respectively.
2.2 The repository was deleted, but for some reason the underlying database or schema remained; now when a new repository is created with the previous name, the underlying database or schema will have the _m001 and _z001 names
Solution
If the count of records in the Change Tracking shows 0, check either of the following:
1. Enablement of Change Tracking for this repository in Console
2. Exact database or schema name in the DBMS.