9-05-07 ABAP FAQ's

->Define service( within R/3) ?
-Ans) A service is a process or group of processes that perform
a specific system function and often provide an application
programming interface for other processes to call.

->What are the roll and page areas ?
Ans) Roll and page areas are SAP R/3 buffers used to store
user contexts ( process requests ) . The SAP dispatcher assigns
process requests to work processes as they are received. If
the work process is unavailable the process requests are queued in the roll and page areas.
Paging area holds data from the application programs.
Roll area holds data from previous dialog steps and data that characterize the user.

->What are the different layers in R/3 system?
Ans) Presentation layer
Application layer
Database layer

->What are the phases of background processing ?
Ans) Job scheduling
Job processing
Job overview

->What components of the R/3 system initiates the start of
background jobs at the specified time ?
Ans) The batch scheduler initiates the start of background job.
The dispatcher then sends this request to an available background
work process for processing.