reg: BDC

[Former Member]

Hi experts,

what is the difference between synchrnous and asynchrous updates in batch input methods.

[Former Member]

Hi,

Synchronous and Asynchronous Updates

Database changes that are made via the SAP Update System and transferred to an update work process, can be carried out synchronously or asynchronously. The mode is specified in the ABAP source code of the SAP transactions and cannot be changed dynamically by the user.

The SAP transaction creates an update request with CALL FUNCTION … IN UPDATE TASK, and transfers this to an update work process. Data is then written to the update tables at the end of a database LUW.

With synchronous updates, the program that outputs the statement COMMIT WORK AND WAIT waits until the update work process outputs the status of the update. The program can then respond to errors separately.

Synchronous updates can never be processed a second time.

As the calling program waits for the result and responds to it appropriately, you can assume that the error has been intercepted. If you try to processs a synchronous update in SM13 again, you will get the message This update request cannot be carried out retrospectively (synchronous update).

Synchronous updates are indicated by the symbol in the Info column in Update Management.

Updates generated by batch input sessions are always carried out synchronously. Batch input with CALL TRANSACTION USING can be updated synchronously and asynchronously. In addition to this, every 100th update in a background job is carried out synchronously in order to avoid delays in the Update System.

With asynchronous updates, the program that outputs the statement COMMIT WORK passes the update onto the Update System and does not wait for the update process to respond.

check this link it contains all abou update techniques

http://abapcode.blogspot.com/search/label/BDC

Regards.

[Former Member]

Hi,

May be the difference helps you understanding the concept.

What is the difference between Synchronous and Asynchronous updates ?

- A program asks the system to perform a certain task, and then either waits or doesn't wait for the task to finish. In synchronous processing, the program waits: control returns to the program only when the task has been completed. In asynchronous processing, the program does not wait: the system returns control after merely logging the request for execution.

What is synchrnous database update ?-

During the processing, no transaction is stored until the previous transaction has been written to the database. This is called Synchronous database update.

<b>Reward points if this helps.

Manish</b>

[Former Member]

Asynchronous Update – The program does not wait for the work process to finish the update. Commit Work.

Synchronous Update – The program wait for the work process to finish the update. Commit Work and Wait.

Asynchronous updating. In this mode, the called transaction does not wait for any updates it produces to be completed. It simply passes the updates to the SAP update service. Asynchronous processing therefore usually results in faster execution of your data transfer program.

Asynchronous processing is NOT recommended for processing any larger amount of data. This is because the called transaction receives no completion message from the update module in asynchronous updating. The calling data transfer program, in turn, cannot determine whether a called transaction ended with a successful update of the database or not.

If you use asynchronous updating, then you will need to use the update management facility (Transaction SM12) to check whether updates have been terminated abnormally during session processing. Error analysis and recovery is less convenient than with synchronous updating.

Synchronous updating. In this mode, the called transaction waits for any updates that it produces to be completed. Execution is slower than with asynchronous updating because called transactions wait for updating to be completed. However, the called transaction is able to return any update error message that occurs to your program. It is much easier for you to analyze and recover from errors

Also check this thread.