BRIEF DISSCUSSION ABOUT DATA DICTINORY

DATA DICTINORY(SE11):

AT FIRST IF U LOGIN SAP MENU  THEN U SEE COMMAND BOX ON THE LEFT UPPER TOP CORNER.

IN THAT COMMAND BOX IS USEFUL FOR TRANSACTION DATA OVER SAP SYSTEM BY USING TRANSACTION CODES(T-CODES)

FIRST TYPE SE11 T-CODE ON COMMAND BOX AND PRESS ENTER.

THEN DATA DICTINORY SCREEN APPEARS .

ABAP DICTINORY COMPLETELY INTEGRATED WITH ABAP WORKBENCH(SE80).

THE FOLLOWING R THE DIFFRENT DATA OBJECTS:

1) TABLE

2)VIEW

3)DATA TYPE

4)TYPE GROUP

5)DOMAIN

6)SEARCH HELP

7)LOCK OBJECT

TABLE:   ITS HAVING ROWS AND COLUMNS. IN TABLE CREATION FIRST FILL COLUMNS OF LEFT SIDE AND GIVE DATA TYPE FOR EACH COLUMN ON RIGHT SIDE.

TABLE IS AN INDEXED FILE: THE MAIN INDEX IS CALLED PRIMARY KEY.

PRIMARY KEY = NOT NULL + UNIQUE.

WE USE PRIMARY KEY   PURPOSE IS THERE R SO MANY TABLES, EACH TABLE HAVING RELATIONSHIP WITH OTHER SO WE GIVE PRIMARY KEY TO RELATE ALL TABLES.

IF THE PRIMARY KEY OF ONE TABLE, IF IT EXSISTS IN THE OTHER TABLE THEN ITS CALLED FOREIGN KEY.

THE MAIN FUNCTION OF FOREIGN KEY IS DATA INTIGRITY.

THERE R ALMOST 8000 TABLES IN ECC SYSTEM. FOLLOWING TYPES OF TABLES R AVAILABLE:

1)TRANSPARENT TABLES: THIS HAVING SAME STRUCTURE IN DICTINORY AND DATABASE. WE ALSO USE STANDARD OPEN SQL.

2)POOLED AND 3) CLUSTER TABLES: THESE R LOGICAL TABLES .HAVING RECORDS OF TRANSPARENT TABLES ALSO.

THESE R NOT MANAGABLE DIRECTLY USING DATABASE SYSTEM TOOLS. CANNOT USE NATIVE SQL.

A) TABLE FIELDS DEFINE FIELD NAMES AND DATA TYPES. U MUST SECIFY REFERENCE FIELDS MEANS FORMAT UNWANTED SELECTION.

B)DELIVARY CLASS: CONTROLS AND TRANSPORT DATA FOR INSTALLATION, UPGRADATION AND CLIENT COPY BETWEEN CUSTOMERS.

USED FOR EXTEND TABLE MAINTAINANCE.

TYPES:  1) A   C   L    G    E    S    AND    W.

MOSTLY USE A AND C.

C)TABLE/VIEW MAINTAINANCE: TABLE IS DISPLAYED IN TOOLS OR NOT WE USE.

VALUES POOSIBLE : DISPLAY/MAINTAINCE ALLOWED.

         DISPLAY/MAINTAINCE ALLOWED WITH RESTRICTIONS.

         DISPLAY/MAINTAINCE NOT ALLOWED.

D)FOREIGN KEY: DFINE RELATIONSHIP BETWEEN TABLE AND OTHER FIELDS.

E)TECHNICAL SETTINGS: CONTROL HOW TABLE CREATED IN DATABASE.

1)HOW TABLE HANDLED

2)WEATHER TABLE BUFFERD R NOT

3)CHANGES TO DATA RECORD OF TABLE WILL BE LOGGED.

  BUFFERING TYPE MEANS  HOW MANY TABLE RECORDS WILL BE LOADED INTO BUFFER WHEN TABLE ENTRY IS ACCESSED.

LOGGING MEANS CHANGES TO TABLE ENTRIES SHOULD BE LOGGED,  SWITCH TO LOGON ,CHANGE TABLE RECORD LONG TIME.

E)INDEX : TO SPEED UP DATA SELECTION ,SECONDARY INDEXES CREATED FOR TABLE.

INDEX IS COPY OF DATABASE TABLE,REDUCE TO CERTAIN FIELDS.

SORTING USE TO FASTER ACCESS DATA RECORDS OF TABLE, USING BINARY SEARCH.

                 VIEW AND TYPES

VIEW CAN BE USED IN ABAP PROGRAMS FOR DATA SELECTION. NORMALLY WE USE APPLICATION OBJECTS DEPENDENT, MEANS NOT REQUIRED FIELDS HIDDEN AND MINIMISE INTERFACES.

IS DERIVED FROM ONE OR MORE TABLES.

1) DATABASE VIEW

2)PROJECTION VIEW

3)MAINTAINCE VIEW

4)HELP VIEW

DATABASE VIEW: IS THE DICTINORY OBJECT WHICH CAN USE TO GET DATA FROM MORE THAN ONE TABLE.

ITS CONTAIN ONE TABLE, MAINTAINCE STATUS CAN BE USED TO DETERMINE IF DATA RECORDS CAN ALSO BE INSERTED IN THE VIEW.

CONTAIN MORE THAN ONE, IF U ONLY READ DATA.

PROJECTION VIEW: HIDE  TABLE FIELDS. THIS CAN MINIMISE INTERFACES. A PROJECTION VIEW CONTAIN EXACTLY ONE TABLE.

EX: WHEN U ACCESS DATABASE,YOU CAN READ  AND WRITE THE FIELD CONTENTS ACTUALLY NEEDED.

HELP VIEW: CAN BE USED AS SELECTION METHOD IN SEARCH HELPS.

MAINTAINANCE VIEW: PERMITS U TO MAINTAIN THE DATA DISTRIBUTED ON SEVERAL TABLESFOR ONE APPLICATION OBJECT AT ONE TIME.

                    DATA TYPE

USER-DEFINED DATA TYPES CAN BE STORED IN THE ABAP DICTINORY. THESE USER-DEFINED TYPES PROVIDES SAME FUNCTIONALITY AS THE LOCAL TYPES CAN BE DEFIENED IN DATA DICTIONARY.

 DEFINE IN GLOBALLY ACESS IN ABAP TYPE.

THERE R THREE DIFFERENT TYPE CATEGEROIES:

.DATA ELEMENTS: ELEMENTARY TYPES AND REFERENCE TYPES.

.STRUCTURES: COMPONENTS ALSO HAVE TYPE.

.TABLE TYPE DEFINE STRUCTURE AND FUNCTIONAL ATTRIBUTES OF AN INTERNAL TABLE.

               TYPE GROUP

USED IN POOL DEFINATIONS.KEY WORD FOR PROGRAMS IS 'TYPE-POOLS'.

1)SLIS: USED IN ALV (ABAP LIST VIEWER REPORTS)

2)TRUXS: BDC PROGRAMS WITH EXCEL DATA

              DOMAIN

A DOMAIN DESCRIBES TECHNICAL ATTRIBUTES OF FIELD, SUCH AS DATA TYPES AND NUMBER OF POSITIONS OF FIELD.TECHNICAL FIELDS COMBINED IN DOMAIN.

   

        SEARCH HELP

OBJECT WITH INPUT HELPS.

TYPES ARE:

1)ELEMENTARY  :  IMPLEMENT SEARCH PATH FOR POSSIBLE ENTRIES.

2)COLLECTIVE : CONTAIN SEVERAL ELEMENTARY SEARCH HELPS. PROVIDES SEVERAL ALTERNATIVE POSSIBLE ENTRIES.

3)APPEND : CAN ENHANCED BY COLLECTIVE SEARCH HELPS DELIVERED BY SAP WITH CUSTOMER-SPECIFIC SEARCH PATHS WITHOUT REQUIRE MODIFICATION.

4)SEARCH HELP EXIT : SPECIFY THE NAME OF A FUNCTION MODULE TO BE CALLED THE SEARCH HELP PROCESS.

                     LOCK OBJECT

 IS VIRTUAL LINK OF SEVERAL SAP TABLES WITH IS USED TO SIMULTANEOUS ACCESS BY THE TWO USERS TO THE SAME SET OF DATA.

LOCK REQUEST FOR PROGRAMMERS FOR ONLINE TRNSACTIONS BY CALLING CERTAIN FUNCTION MODULES FROM LOCK OJECTS.

Read Lock (Shared Locked)
   protects read access to an object. The read lock allows other  transactions read access but not write access to the locked area of the table
- Write Lock (exclusive lock) 
   protects write access to an object. The write lock allows other  transactions neither read nor write access to the locked area of the  table.
- Enhanced write lock (exclusive lock without cumulating) 
  works like a write lock except that the enhanced write lock also  protects from further accesses from the same transaction.
You can create a lock on a object of SAP through transaction SE11 and enter any meaningful name start with EZ Example EZTEST_LOCK.