extracting LDB

[Former Member]

Hi,

Can you please tell me how to extract a LDB from R/3 using Generic data extraction?

And one more doubt,

When we are extracting data from R/3, with which layer of R/3(Application/Database) our BW system interacts?

In R/3 where(In Application layer/Database layer) LDBs stored? How BW accesses LDBs?

Thanks

Surya.

[Former Member · Accepted solution]

Hi Surya,

there are two ways of using a logical database: either by linking it with an executable program or by using the function module LDB_PROCESS in any ABAP program.

You can use directly these methods in your generic extractor or you can fill before a table and then build a datasource on it.

A logical database is made up of three components (a structure that defines the data view of the logical database, a selection screen and a database program that contains the ABAP statements used to read the data and pass it to the user of the logical database)...as you can understand, LDBs are not really physical DB, but only logical view based on a foreign key relationships between hierarchical tables in the R/3 System.

Hope it helps.

Bye,

Roberto

[Former Member · Accepted solution]

Hi Roberto,

So, what i have understood is LDBs are not stored in the Database layer, those are stored in the Application layer of R/3, Right?

And one more, when we are extracting LIS structures the BW interacts with Database layer of R/3, Right?

-Surya

[Former Member · Accepted solution]

Ok,

LDB is a logical view (in application layer) of data contained in database layer (that consists of a central database system containing ALL of the data in the R/3 system !).

When you extract your data from BW, both Application Layer and Database Layer are involved (Presentation Layer too if you use the GUI): the application layer of an R/3 is made up of the application servers and the message server; application programs (as our extraction pgm) run on application servers that communicate with the database (layer) thanks to work processes...

Hope now is clearer...

Bye,

Roberto