topic Re: bdc in Application Development and Automation Discussions

bdc

Former Member — Tue, 01 May 2007 11:11:11 GMT

what is the difference between session method and direct input ?

Re: bdc

Former Member — Tue, 01 May 2007 11:12:55 GMT

Hi pinky,

1. In direct input, the tables are directly update, instantly.

2. Whereas in session method,

a) an intermediate storage area is there,

where whole data is stored. This is called session.

when we run this session, Only then the data gets updated.

b) it is done via transaction and not thru direct update of tables.

regards,

amit m.

Re: bdc

Former Member — Tue, 01 May 2007 12:16:39 GMT

Hi,

1. In direct input, the tables are directly update, instantly and it will be asynchronous usally its used for immediate updation of data when the amount of data is less.only one transaction can be updated by this method

2. Whereas in session method,

Is used for large data updatin n it can be shedule for an later ime also when the server is not busy there is an intermediate storage area is there called session

where whole data is stored we can shedule this session for any later timing Only then the data gets updated.also we can update more than one transacion in this method

the FM used with this method are

reward if helpful

ravi

Re: bdc

Former Member — Tue, 01 May 2007 12:34:27 GMT

Hi,

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.

Regards

Sudheer

Re: bdc

Former Member — Tue, 01 May 2007 13:02:13 GMT

Hi,

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.

Session Method:

Asynchronous processing.

Synchronous Processing in database update.

Transfer data for more than one transaction.

Batch input processing log will be generated.

During processing, no transaction is started until the previous transaction has been written to the database.

Data consistency check with help of screen logic. Batch Input is a standard technique for transferring large sets of data into the SAP System. The transaction flow is transferred as if it were entered online. The advantage of this is that all relevant check for the transaction are executed, thereby ensuring that the data is consistent.

Direct Input:

A recent technique to input data safely. An alternative to batch input.

With direct input, the SAP function modules execute the consistency checks. However with batch input, these consistency checks are executed with help of the screens. This means that direct input has considerable performance advantages. But there are a few programs for direct input, you can use them if it accomplishes your goal. Direct Input programs work like that they update database tables directly. As you know that it is forbidden to update SAP database tables directly, since consistency and security should be considered. Exceptions are these direct input programs. So you are not able to write custom ABAP direct input programs. But of course you can write ABAP programs to update custom database tables (Z tables), if you are sure all about consistency.

SAP has created direct input programs because SAP wanted to enhance the batch input procedure, since batch input is slower. SAP offers the direct input technique, especially for transferring large amount of data. In contrast to batch input, this technique does not create sessions, but stores, updates, inserts data directly. To enter the data into the corresponding database tables directly, the system calls a number of function modules that execute any necessary checks. In case of errors, the direct input technique provides a restart mechanism. However, to able to activate the restart mechanism, direct input programs must be executed in the background only. To maintain and start these programs, use program RBMVSHOW or transaction BMV0.

Also check the following link,

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

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