Differences between Call Transaction and Session Method in BDC

Batch Input Vs. Call Transaction

• In Batch input many transactions can be executed, where as in Call transaction only one transactioin can be executed.
• Batch input is a background process, Call transaction can be either background or foreground .
• Batch input is Synchronous process, Call transaction is both Asynchronous & Synchronous.
• Batch input Sessions cannot be runed parallel.
• Log file is generated automaticly in Batch input, errors can be found through BDCMSGCOLL.
• Batch input works for multiple applications where as call transactions doen't work
• Batch input has an implicit log file with it. where as call transaction doesn't have
• Batch input has sy-subrc check with the database where as call transaction doesn't have so call transaction is fast.

The most important aspects of the batch session interface are: - Asynchronous processing - Transfers data for multiple transactions - Synchronous database update During processing, no transaction is started until the previous transaction has been written to the database. - A batch input processing log is generated for each session - Sessions cannot be generated in parallel.

The most important aspects of the CALL TRANSACTION USING interface are: - Synchronous processing - Transfers data for a single transaction - Synchronous and asynchronous database updating both possible The program specifies which kind of updating is desired. - Separate LUW for the transaction The system performs a database commit immediately before and after the CALL TRANSACTION USING statement. - No batch input processing log is generated.

We can use two methods to perform Batch Data Communication(BDC):

Call Transaction Method: In Call Transaction method we call the transaction in BDC program itself. If we want this program is executed by some one else then we need to expose the code to him. Call Transaction Method Works in Foreground. No Display Mode is equal to Background Processing in call transaction method. Call Transaction Method can handle only one Application at a time. In Call Transaction Method no Log File by Default. We have to design Log File by using BDCMSGCOLL. Call Transaction Method Updates the Database Asynchronously. 

(Note: Asynchronous updation is Faster than Synchronous)
 
Batch Session Method: On the other hand in batch session method we create a session which can be executed at any time by any authorized person without exposing the code of the program. Session Method works in Background and as well as in Foreground. Session Method can handle Multiple Applications at a time. Session Method holds Log File by Default. Session Method Updates the Database Synchronously.