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OpenEdge Change Data Capture Guide
CDC Schema : Change Tracking Table

Change Tracking Table

The following table describes the fields of the _Cdc-Change-Tracking table.
Table 10. _Cdc-Change-Tracking fields
Table Policy Id
Transaction number
timestamp tz
Timestamp of database trigger execution – UTC with zone
Sequence of change within the Object for a policy Id
Value to indicate what type of operation is occurring:
*1 — Create
*2 — Delete
*3 — Before Update
*4 — After Update
*5 — Field Delete (in Source Table)
*6 — Partition Drop
*7 — Partition Truncate
*8 — Partition Deallocate
*9 — MT Partition Deallocate
*10 — MT Partition Drop
*11 — Merge Partition Drop
*12 — Field Add (in Change Table, also specifies re-tracking of a field)
ABL/SQL methods are provided to access values in this field.
Support for Pro2
Support for TP
Support for MT
Future to support change table record format changes
char x(8)
User defined field — possible use to mark it when an operation has occurred that moved a record to the external data source.
char x(8)
Reserved for future use
The following table describes the indexes of the _Cdc-Change-Tracking table.
Table 11. _Cdc-Change-Tracking indexes
Index Name
Index Field
1 _Source-Table-Number (These two fields together point to a single instance of the table)
2 _Change-Sequence
1 _Source-Table-Number
2 _Time-Stamp
3 _Change-Sequence
Non Unique
1 _Source-Table-Number
2 _Partition-Id
3 _Recid
4 _Change-Sequence
The CDC Change Tracking Table is a table used by all change record capture activities. The table tracks each CUD (create/update/delete) activity by a change sequence order. This table can be used to drive query activity in the CDC Change Table. The database CDC trigger will write a Change Tracking and Change Table record in most cases when it is executed. Understanding the connection between the two tables is important because data describing the change activity is stored in the Change Tracking Table. When accessing the the data in the Change Table, use the Change Tracking Table to establish record modification sequence and which fields changed in the Source Table.