We come across change pointer technique while dealing with master data distribution thru ALE/IDOCs
When we want to reflect changes made to master data (i.e
customer master, vendor master, material master) visible to other clients
listed in customer distribution model, we follow change pointer technique.
What is customer distribution model?
A customer model depicts various messages (master data, transactional data) exchanged between the systems and establishes a sender and receiver of data.
A customer model is always maintained on any system for the entire distributed network of SAP systems, so it must be distributed to various systems in the distributed network.
These are some details regarding change pointer technique which you may find it useful.
The change pointers technique is based on the change document technique, which tracks changes made to key documents in SAP, such as the material master, customer master, vendor master & sales orders. changes made to a document are recorded in the change document header table CHDHR, and additional change pointers are written in the BDCP table for changes relevant to ALE. BDCPS table stores the status of changed documents processed or not.
The process for distributing master data using change pointers involves the following steps.
The application writes change documents. SAP maintains change documents for several objects in the system, such as materials, customers, invoices, and bank data, to provide an audit trail for changes made to an object. A change document object represents a set of tables for which changes are recorded. For example, the change document for the material master is named MATERIAL and it contains the various tables of the material master object, such as MARA and MARC.
When an application transaction makes changes to an object, the application writes change documents, which are stored in the CDHDR and CDPOS tables for each change made to an object.
Tip
Execute transaction SCDO to see a list of change document objects and their tables.
The SMD (Shared Master Data) tool writes change pointers. When changes are made to an object, the SMD tool checks the ALE settings and consults the ALE distribution model to determine whether a receiver is interested in the object that was changed. If the system finds an appropriate receiver, the system creates change pointers in the BDCP table that point to change documents in the CDHDR table.
The ALE programs analyze change pointers and generate IDocs. SAP provides standard function modules that read the change pointer table and generate IDocs for the objects that were changed. These programs are designed to ignore multiple changes and create only one IDoc. For example, if a material is changed four times before the function module is invoked, only one IDoc with the latest data from the material master data is created. The function modules are invoked by a standard report, RBDMIDOC. The selection parameters of this report allow you to specify the message type for which change pointers are to be analyzed. Configuration you must carry out the following configuration steps to enable master data distribution based on changes to the object.
Step 1: Enable Change Pointers Globally
Transaction: BD61
This option enables the change pointer process globally.
Make sure that the flag is checked.
Step 2: Enable Change Pointers for a Message Type
Transaction: BD50
This setting is required for activating change pointers
for a specific message type. Make sure that the Active flag is checked
for your message type.
Step 3 :Specify the Fields for Which Change Pointers Are to Be Written
Transaction: BD52
For standard master data objects such as the material,
customer, and vendor objects, SAP already provides a list of fields for
which change pointers are written. If you are satisfied with the standard
set of fields, you can skip this step. If you want to add new fields, you
must add entries for the required fields. If you are not interested in
IDocs being generated for changes to a particular field, you can remove
it from the list. For example, if you do not want to distribute the material
master for changes made to the Catalog Profile (RBNRM) field, you can delete
this entry from the table.
Step 4: Changing a Field in the Master Data
Change a field in the master data object for which the change pointer is enabled. For example, if you change the net weight of a material in the material master data, a change pointer is written.
Tip : You can verify a change document and change pointer
by viewing entries in tables CDHDR and BDCP, respectively.
Step 5 :Executing Program RBDMIDOC to Process Change Pointers
Execute program RBDMIDOC to initiate the process of generating an IDoc. On the selection screen, specify the message type. For example, you can specify MATMAS. After you execute the process, it displays the number of entries processed.
Note :
Normally, you schedule this program to run frequently
and start IDoc generation for different message types.
Step 6 : View the idocs in WE02/05
