2. Architecture

Components are reusable units of the application projects .  Components  appear as nodes within the object list on the left side of the workbench window.

The Components(sub-objects)  of an ABAP programs are :

1. Source Code  :  Instruction written by ABAP programmers that are interpreted by  SAP ABAP                                      language interpreter.
2. Variants   :  Input values that can change but not are frequently used
3. Attributes  :  properties of ABAP program like Program type, title ,created date etc.
4. Documentation  :  helps other programmers to understand program flow.
5.Text Element   :   Short description like  report column heading .

 
Generally there are two types of ABAP programms .

•  Reports ( interactive & traditional ) with selection screen  and output screen.
• Dialogs

1. What is ABAP?

Application programs running inside R/3 are written using SAP's proprietary programming language
ABAP.

Netweaver as (Application server) combines which SAP calls  two "personalities "  because  Webdynpro (pronounced web din pro ) for ABAP and Webdynpro for java use the same meta model.

Webdynpro components, views , models, and conytrollers have the same semantic in both ABAP and JAVA.

The main difference is design time environment, the developement infrastructure and the run time environment.

DDIC

DDIC objects are data dictionary objects, anything that you can create via SE11, including Tables, Data Elements, Domains, Search Helps, Lock Objects, Views, structures, table types, etc.

The ABAP Dictionary centrally describes and manages all the data definitions used in the system. The ABAP Dictionary is completely integrated in the ABAP Development Workbench. All the other components of the Workbench can actively access the definitions stored in the ABAP Dictionary.

The ABAP Dictionary supports the definition of user-defined types (data elements, structures and table types). You can also define the structure of database objects (tables, indexes and views) in the ABAP Dictionary. These objects can then be automatically created in the database with this definition. The ABAP Dictionary also provides tools for editing screen fields, for example for assigning a field an input help (F4 help).

The most important object types in the ABAP Dictionary are tables, views, types (data elements, structures, table types), domains, search helps and lock objects

Interview questions for ABAP'er

Q.         Abstract class & interface

Q.       At line-selection

Q.            Component for dialog program

                                 Q .             conversion exit

Q.          formatting option for date field

Q. DELIVERY CLASS FOR TABLE 

Q.          DICTIONARY TASKS

Q. DIFFERENCE B/W TABLES

                                            Q.     EVENTS

Q.             FORMATTING CLAUSE

                             Q.                HOTSPOT

Q. AT LINE-SELECTION           AT USER-COMMAND

Q. USER DEFINE TYPES

Q.           ABAP DICTIONARY

Q.           TYPES IN ABAP DICTIONAARY

Q.           CONSTANTCS AND LITERALS

Q.  NUMERIC TYPE FORMATE

Q.                OLTP   & OLAP

Q.         OOPs

Q.      OPERATORS

Q.    DECISION MAKING STATEMENT

Q.       STRING MANIPULATE

Q.       STRUCTURE

Q.     SYSTEM FIELDS FOR SECONDARY LIST

Q.       TIME STAMP

Q.         TYPES OF TABLE FIELD

DIFFERENCE BETWEEN INTERNAL TABLE AND WORK AREA

INTERNAL Table and it's background:

===================================

Internal table acts as a container which is used to store the record sets. That is used to store the data fetched from the database table.

So due to performance reason every time access to database would not be so good and decrease the performance. So you just select the data from the database and store it in the intermediate table. This table is called INTERNAL TABLE. So it's an replica of the database. The design foes like this,

PRESENTATION SERVER <> APPLICATION SERVER <>

DATABASE SERVER.

So everytime gain accessing to database results in high resource usage and bad permformance.

So always play around with internal tables. So obviously the whenever you access the data in the INTERNAL TABLE, the application server will be used.

WORK AREA:

==========

When ever you loop at the internal table, the current record should be stored in a temporary work place. That is called WORK AREA.

LOOP AT ITAB INTO WORKAREA.

ENDLOOP.

ITAB :An internal table

WORKAREA:An instance of internal table

Go thru the link below

Internal tables

appending internal tables.

reward if it helps..

Difference between Abstract class and Interface

Abstract class is the class in which there is atleast one

abstract method.abstract method is the method which does not

have any body defined in that class.We cannot make any object of

the abstract class.So, that abstract class must be derived by

the subclass which defines all the abstract methods of the super

class.If the sub class doesnot define any abstract meth. of the

super class, then that sub class automatically becomes the

abstract class.When the sub class defines all the abs. meth.s of

the super class then we can make the object of the sub class and

access the other methods of the abs. super class.

An interface is the class that have all the methods as abs.

methods.All the instance variables of an interface must be

declared as final and static.Now we can implement this interface

in another class which must define all the methods of the

interface.Now make the obj. of the class that implemented the

interface.

Interfaces are used where we want the users to use the specified

methods only.Abstract classes are used in inheritence where

there is no need for the class to define any method which must

be defined in the sub classes.

Please the feedback for the above answer.There's too much about

the abstract class n interface so i could not write everything.I

think this must clear ur doubts.

SAP HANA

SAP HANA: Simply Explained

This article is for SAP HANA beginners, who don’t really understand what it is about and are lost in all the marketing and technical jargon.

What is SAP HANA?

SAP HANA is the latest in-memory analytics product from SAP; using HANA companies can do ad hoc analysis of large volumes of data in real-time.

What is in-memory?
In-memory means all the data is stored in the memory (RAM). This is no time wasted in loading the data from hard-disk to RAM or while processing keeping some data in RAM and temporary some data on disk. Everything is in-memory all the time, which gives the CPUs quick access to data for processing.

What is real-time analytics?
Using HANA, companies can analyze their data as soon as it is available. In older days, professionals had to wait at least few hours before they could analyze the data being generated around the company. To put this in perspective, let us take an example – suppose a super market chain wants to start giving you discount coupons when you visit them based on your shopping habits. Before: they could only mail them to your address or give you coupons for your next purchase. Now: while you are checking out, your entire shopping history can be processed and discount could be given on the current shopping. Imagine the customer loyalty for such a chain!

So is SAP making/selling the software or the hardware?

SAP has partnered with leading hardware vendors (HP, Fujitsu, IBM, Dell etc) to sell SAP certified hardware for HANA. SAP is selling licenses and related services for the SAP HANA product which includes the SAP HANA database, SAP HANA Studio and other software to load data in the database. Also, as already announced, the vision is to run all the application layer enterprise software on the HANA platform; that is ERP/BW/CRM/SCM etc /etc will use HANA as their database.

Can I just increase the memory of my traditional Oracle database to 2TB and get similar performance?

Well, NO. You might have performance gains due to more memory available for your current Oracle/Microsoft/Teradata database but HANA is not just a database with bigger RAM. It is a combination of a lot of hardware and software technologies. The way data is stored and processed by the In-Memory Computing Engine (IMCE) is the true differentiator. Having that data available in RAM is just the icing on the cake.

Is HANA really fast? How is it possible that HANA is so fast?

HANA is fast due to many reasons. The following picture¹ depicts a very simplified version of what’s inside the In-memory Computing Engine.