session and call transaction

[Former Member]

Why we go for session method if we have large amount of data ?

can't we use call transaction using synchronus update for large amount of data?

[Former Member]

Why we go for session method if we have large amount of data ?

can't we use call transaction using synchronus update for large amount of data?

[Former Member]

CALL TRANSACTION:

Single transaction can be processed always.

Synchronous Processing - means Transfers data for a single transaction.

Asynchronous and Synchronous Database Update is possible.

No Session Log is created

Faster as it Asynchronous Update is possible.

Returns the SY-SUBRC value.

SESSION METHOD:

Multiple Transactions can be Processed through the same session.

Asynchronous processing - means Transfers data for multiple transactions.

Synchronous updates only possible - means no transaction is started until the previous transaction has been written to the database.

Session log is created.

Slower as it is Synchronous Update only.

Doesn't return the SY-SUBRC value.

Both call transaction and session method has diffrent functionality.

if you have huge amount of data in file ,then go for session method,

if you have run time validation ,then go for Call transaction

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.

Reward points if useful.

[Former Member]

Hi,

SESSION METHOD

About Session method

In this method you transfer data from internal table to database table through sessions.

In this method, an ABAP/4 program reads the external data that is to be entered in the SAP System and stores the data in session. A session stores the actions that are required to enter your data using normal SAP transaction i.e., Data is transferred to session which in turn transfers data to database table.

Session is intermediate step between internal table and database table. Data along with its action is stored in session i.e., data for screen fields, to which screen it is passed, the program name behind it, and how the next screen is processed.

When the program has finished generating the session, you can run the session to execute the SAP transactions in it. You can either explicitly start and monitor a session or have the session run in the background processing system.

Unless session is processed, the data is not transferred to database table.

BDC_OPEN_GROUP

You create the session through program by BDC_OPEN_GROUP function.

Parameters to this function are:

• User Name: User name

• Group: Name of the session

• Lock Date: The date on which you want to process the session.

• Keep: This parameter is passed as ‘X’ when you want to retain session after

processing it or ‘ ‘ to delete it after processing.

BDC_INSERT

This function creates the session & data is transferred to Session.

Parameters to this function are:

• Tcode: Transaction Name

• Dynprotab: BDC Data

BDC_CLOSE_GROUP

This function closes the BDC Group. No Parameters.

Some additional information for session processing

When the session is generated using the KEEP option within the BDC_OPEN_GROUP, the system always keeps the sessions in the queue, whether it has been processed successfully or not.

However, if the session is processed, you have to delete it manually. When session processing is completed successfully while KEEP option was not set, it will be removed automatically from the session queue. Log is not removed for that session.

If the batch-input session is terminated with errors, then it appears in the list of INCORRECT session and it can be processed again. To correct incorrect session, you can analyze the session. The Analysis function allows to determine which screen and value has produced the error. If you find small errors in data, you can correct them interactively, otherwise you need to modify batch input program, which has generated the session or many times even the data file.

CALL TRANSACTION

About CALL TRANSACTION

A technique similar to SESSION method, while batch input is a two-step procedure, Call Transaction does both steps online, one after the other. In this method, you call a transaction from your program by

Call transaction <tcode> using <BDCTAB>

Mode <A/N/E>

Update <S/A>

Messages into <MSGTAB>.

Parameter – 1 is transaction code.

Parameter – 2 is name of BDCTAB table.

Parameter – 3 here you are specifying mode in which you execute transaction

A is all screen mode. All the screen of transaction are displayed.

N is no screen mode. No screen is displayed when you execute the transaction.

E is error screen. Only those screens are displayed wherein you have error record.

Parameter – 4 here you are specifying update type by which database table is updated.

S is for Synchronous update in which if you change data of one table then all the related Tables gets updated. And sy-subrc is returned i.e., sy-subrc is returned for once and all.

A is for Asynchronous update. When you change data of one table, the sy-subrc is returned. And then updating of other affected tables takes place. So if system fails to update other tables, still sy-subrc returned is 0 (i.e., when first table gets updated).

Steps for CALL TRANSACTION method

1. Internal table for the data (structure similar to your local file)

2. BDCTAB like BDCDATA

3. UPLOAD or WS_UPLOAD function to upload the data from local file to itab. (Considering file is local file)

4. Loop at itab.

Populate BDCTAB table.

Call transaction <tcode> using <BDCTAB>

Mode <A/N/E>

Update <S/A>.

Refresh BDCTAB.

Endloop.

(To populate BDCTAB, You need to transfer each and every field)

The major differences between Session method and Call transaction are as follows:

SESSION METHOD CALL TRANSACTION

1. Data is not updated in database table unless Session is processed. Immediate updation in database table.

2. No sy-subrc is returned. Sy-subrc is returned.

3. Error log is created for error records. Errors need to be handled explicitly

4. Updation in database table is always synchronous Updation in database table can be synchronous Or Asynchronous.

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

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

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.

L Local updating. If you update data locally, the update of the database will not be processed in a separate process, but in the process of the calling program. (See the ABAP keyword documentation on SET UPDATE TASK LOCAL for more information.)

http://myweb.dal.ca/hchinni/sap/bdc_home.htm

https://www.sdn.sap.com/irj/sdn/wiki?path=/display/home/bdc&;

http://www.sap-img.com/abap/learning-bdc-programming.htm

http://www.sapdevelopment.co.uk/bdc/bdchome.htm

http://www.sap-img.com/abap/difference-between-batch-input-and-call-transaction-in-bdc.htm

http://help.sap.com/saphelp_47x200/helpdata/en/69/c250684ba111d189750000e8322d00/frameset.htm

http://www.sapbrain.com/TUTORIALS/TECHNICAL/BDC_tutorial.html

Check these link:

http://www.sap-img.com/abap/difference-between-batch-input-and-call-transaction-in-bdc.htm

http://www.sap-img.com/abap/question-about-bdc-program.htm

http://www.itcserver.com/blog/2006/06/30/batch-input-vs-call-transaction/

http://www.planetsap.com/bdc_main_page.htm

Reward is usefull

Thanks.

[Former Member]

Thank u nagraj patil.

I have understood clearly. You said that , If you find small errors in data, you can correct them interactively in session method. Can u explain this sentence please?

[Former Member]

hi,

Call transaction is faster then session method. But usually we use session method in real time…because we can transfer large amount of data from internal table to database and if any errors in a session. Process will not complete until session is corrected.

Hope this is helpful, Do reward.