Table CDC

This page shows how to use the Table CDC extraction type.
The Table CDC extraction type loads incremental data from SAP Tables. Unlike a full data load that transfers all records, CDC captures only data that has changed since the last load.

About Table CDC

Change Data Capture (CDC) is a method to keep track of data changes such as insert, update and delete in SAP tables. The Table CDC extraction type creates a log table in SAP that records any changes made to a selected table. The content of the log table is cleared after every successful run of the extraction. Data that was not extracted is not cleared from the log table.

For a detailed overview of this process, refer to the Knowledge Base Article: Delta Mechanism of TableCDC.

General workflow for Table CDC extractions:

System Requirements

• The Table CDC extraction type is compatible with SAP ECC 5.0 and higher
• Supported databases:
  • HANA
  • SQL Server
  • ASE (SAP Adaptive Server Enterprise, formerly Sybase)
  • Oracle
  • IBM Db2
  • IBM for i (Db4)
  • IBM for z/os (Db6)
  • MaxDB

Prerequisites

• The following custom function modules are installed in SAP:

  • /THEO/READ_TABLE
  • /THEO/CDC_ECC or /THEO/CDC_S4

  The SAP transport requests for the function modules are provided in the installation directory: C:\Program Files\XtractUniversal\ABAP\.

• A connection to an SAP system is available, see SAP Connection.

• The SAP user has sufficient user rights, see SAP Authority Objects.

Create a Table CDC Extraction

1. In the main window of the Designer, click [New] to create a new extraction. The window "Create Extraction" opens.
   
2. Select an SAP Connection of type RFC from the drop-down menu Source.
3. Enter a unique name for your extraction.
4. Select the extraction type Table CDC.
5. Click [OK]. The main window of the extraction type opens automatically.

The majority of the functions of the extraction type can be accessed in the main window.

Look Up a Table

1. In the main window of the extraction type, click [ ]. The window “Table Lookup” opens.
   
2. In the field Table Name, enter the name of the table to track and extract . Use wildcards (*) if needed.
   
3. Click [ ] . Search results are displayed.
4. Select a table and click [OK].
   

All relevant metadata information of the table is retrieved from SAP. The application returns to the main window of the extraction type.

Define the Table CDC Extraction Type

The Table CDC extraction type offers the following options for tracking SAP tables:

1. Select the table columns you want to track and extract. By default all columns are selected. Deselect the columns you do not want to extract.
   
2. Activate Extract table on first run to extract the table when first running the extraction.

3. Optional: Use Log table row limit to set a maximum number of rows that the log table can contain. If the row limit is reached, the extraction fails with an exception. The maximum row limit of a log table is 500.000. The row limit is disabled by default (value 0).

   Note

   Once a log table is initialized, you cannot change the size limit anymore.

4. Optional: Define a WHERE Clause to filter table records. By default all data is extracted.

5. Click [Load live preview] to display a live preview of the first 1000 records.
   
   • The column TS_TIMESTAMP contains a timestamp of when the data was last changed.
   • The column TS_OPERATION indicates if a row was inserted (I), updated (U) or deleted (D).
     
6. Check the Extraction Settings and the General Settings before running the extraction.
7. Click [OK] to confirm your settings.

To initialize the tracking of the selected SAP table, run the extraction once.

Initialize the Log Table

Run the extraction for the first time to create a log table in SAP that records any changes made to a selected table or view:

1. Select the extraction in the main window of the Designer.
2. Click [ Destination] to assign the destination where you want to write data to .
   
3. Click [Run] . The window "Run Extraction" opens.
4. Click [Run] to run the extraction.
   
5. If the extraction is successful, the status in the General Info section of the window changes to "finished successfully". If an error occurred, you can find information on the error in the Log section of the window.

The log table in SAP is now available for the Table CDC component. The extracted SAP table is now available in your destination.

Source Table Changes

After initializing the log table, you can make the following changes to the SAP source table:

• add new columns
• delete existing columns that are not part of the primary key (as of SAP Basis 7.76, S4H 1905)
• change columns that are not part of the primary key (as of SAP Basis 7.76, S4H 1905)

For more information, see SAP Note 2814740.

After changing a source table, open the corresponsing Table CDC extraction and click [Refresh Metadata] to update your Table CDC extraction.

Delete Log Table and Triggers

When a Table CDC extraction is no longer in use, simply deleting the extraction is not enough. To delete the log table and all associated triggers from your SAP system, open the Table CDC extraction and click [Delete CDC resources].

To delete the SAP resources of multiple extractions or extractions that are already deleted, see Active CDC Watches.