ABAP Questions

Transparent tables: Transparent tables in the dictionary has a one-to-one relation with the table in database. Its structure corresponds to single database field. Table in the database has the same name as in the dictionary. Transparent table holds application data.

Pooled tables: Pooled tables in the dictionary has a many-to-one relation with the table in database. Table in the database has the different name as in the dictionary. Pooled table are stored in table pool at the database level.

ABAP Editor: Tool in the ABAP Workbench in which you enter the source code of ABAP programs and check their syntax. You can also navigate from the ABAP Editor to the other tools in the ABAP Workbench.

Call transaction is faster than 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, then process will not complete until session get correct.

1. Initialization
2. At selection-screen
3. Start-of-selection
4. End-of-selection
5. Top-of-page
6. End-of-page
7. At line-selection
8. At user-command
9. At PF
10. Get
11. At New
12. At LAST
13. AT END
14. AT FIRST

Dispatcher recieves the request from client and assigns the request to one of the work process.
Roll area: Each workprocess works in a particular memory that memory is known as Role Area, which consists of User context and session data.
ABAP- Processor :is an interpretor which can execute logic

sap memory is a global memory whereas abap memory is local memory.

For example, we have four programs in abap memory and assigned some varibles to a particular program in abap memory then those varibles can't be used by anyother program in abap memory i.e., the variables are only for that program and also local to that memory,whereas sap memory can access all the abap memory or else it can perform any kind of modifications.

advantages: view is used to retrieve the data very fastly from the database tables
* memory wastage is reduced
* faster than joins to retrieve the data from database tables

disadvantages:
* view is not a container,it will not hold the data
* view memory is not permanent memory

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.