bdc question

Session method. coz it will automatically creates error log. it can be used with more number of records than call.

Selection of BDC Method depends on the type of the requirement you have. But you can decide which one will suite requirement basing the difference between the two methods. The following are the differences between Session & Call Transaction.

Session method.

1) synchronous processing.

2) can tranfer large amount of data.

3) processing is slower.

4) error log is created

5) data is not updated until session is processed.

Call transaction.

1) asynchronous processing

2) can transfer small amount of data

3) processing is faster.

4) errors need to be handled explicitly

5) data is updated automatically

Batch Data Communication (BDC) is the oldest batch interfacing technique that SAP provided since the early versions of R/3. BDC is not a typical integration tool, in the sense that, it can be only be used for uploading data into R/3 and so it is

not bi-directional.

BDC works on the principle of simulating user input for transactional screen, via an ABAP program.

Typically the input comes in the form of a flat file. The ABAP program reads this file and formats the input data screen by screen into an internal table (BDCDATA). The transaction is then started using this internal table as the input and executed in the background.

In ‘Call Transaction’, the transactions are triggered at the time of processing itself and so the ABAP program must do the error handling. It can also be used for real-time interfaces and custom error handling & logging features. Whereas in

Batch Input Sessions, the ABAP program creates a session with all the transactional data, and this session can be viewed, scheduled and processed (using Transaction SM35) at a later time. The latter technique has a built-in error processing mechanism too.

Batch Input (BI) programs still use the classical BDC approach but doesn’t require an ABAP program to be written to format the BDCDATA. The user has to format the data using predefined structures and store it in a flat file. The BI program then reads this and invokes the transaction mentioned in the header record of the file.

Direct Input (DI) programs work exactly similar to BI programs. But the only difference is, instead of processing screens they validate fields and directly load the data into tables using standard function modules. For this reason, DI programs are much faster (RMDATIND - Material Master DI program works at least 5 times faster) than the BDC counterpart and so ideally suited for loading large volume data. DI programs are not available for all application areas.

synchronous & Asynchronous updating:

http://www.icesoft.com/developer_guides/icefaces/htmlguide/devguide/keyConcepts4.html

synchronous & Asynchronous processings

Asynchronous refers to processes that do not depend on each other's outcome, and can therefore occur on different threads simultaneously. The opposite is synchronous. Synchronous processes wait for one to complete before the next begins. For those Group Policy settings for which both types of processes are available as options, you choose between the faster asynchronous or the safer, more predictable synchronous processing.

By default, the processing of Group Policy is synchronous. Computer policy is completed before the CTRLALTDEL dialog box is presented, and user policy is completed before the shell is active and available for the user to interact with it.

Note

You can change this default behavior by using a policy setting for each so that processing is asynchronous. This is not recommended unless there are compelling performance reasons. To provide the most reliable operation, leave the processing as synchronous.

reward points if it helps to you.

I will Prefer BDC session Method...Because of error handling...

In Session method, The records are not added to the database until the session is processed. sy-subrc is not returned. Error logs are created for error records. Updation in database table is always Synchronous.

In Call Transaction method: The records are immediately added to the database table. sy-subrc is returned to 0 if succesful. Error logs are not created and hence the errors need to be handled explicitly. Updation in database table is either Synchronous or Asynchronous.

Regards,

Maha

Session method -

> When i have to transfer large amount of data.Though it is slower than call transcation ,it is the preffered choice.

Call Transcation -

> When i have to transfer small amount of data.