Wednesday, August 1, 2007

Data Dictionary


What is a domain?

Domain describes the technical attributes for a field.


What are in-build data type?

  1. ACCP Posting period YYYYMM
  2. CHAR Character String
  3. CLNT Client
  4. CUKY Currency key, referenced by CURR fields
  5. CURR Currency field, stored as DEC
  6. DATS Date field (YYYYMMDD) stored as char(8)
  7. DEC Counter or amount field with comma and sign
  8. FLTP Floating point number, accurate to 8 bytes
  9. INT1 1-byte integer, integer number <= 255
  10. INT2 2-byte integer, only for length field before LCHR or LRAW
  11. INT4 4-byte integer, integer number with sign
  12. LANG Language key
  13. LCHR Long character string, requires preceding INT2 field
  14. LRAW Long byte string, requires preceding INT2 field
  15. NUMC Character string with only digits
  16. PREC Precision of a QUAN field
  17. QUAN Quantity field, points to a unit field with format UNIT
  18. RAW Uninterrupted sequence of bytes
  19. RSTR Byte String of Variable Length
  20. SSTR Short Character String of Variable Length
  21. STRG Character String of Variable Length
  22. TIMS Time field (hhmmss), stored as char(6)
  23. VARC Long character string, no longer supported from Rel. 3.0
  24. UNIT Unit key for QUAN fields


What is a conversion routine in domains?

While writing a values or reading a values form the data base the abap interpreter uses conversion routines so as to retrieve / write values from the data base

E.g. MATNR has conversion routine MATN1 associated with it

and its length is 18 char but if value entered is only 10 char

then rest is padded by zeros and stored and completed 18 char

this is done by conversion routine and while reading the same

its read as 18 char but displayed as 10 char only.

Following FMs can be used for conversion while



Conversion exit ALPHA, external->internal


Conversion exit ALPHA, internal->external


What is value range?

When user press F4 help on a field a list of values appears in a pop up this is nothing but the value help that is provided at the domain level, this can be single value, range or another database table.


What is a data element?

Data element is those which can use domains and inherit the data type or can directly be associated with a data type and are used in table for assignment to a table field.


What is a parameter id in data element?

When a data element is being used, a memory space is allocated for that element which is recognized by parameter id.


Can documentation be provided in data element?

Yes, using the Documentation button and is displayed when user press F1 on that field.


What is the use of field labels in data element?

Displayed when these data elements are used in screens.


What are views?

A view is a logical view on one or more tables, that is, a view is not actually physically stored, instead being derived from one or more other tables.


What are the types of views?

a) Projection

b) Database

c) Maintenance

d) Help


What is the difference between database and projection view?

Projection view: Is formed on a single table.

Database view: Is formed on one or more tables.


What is the prerequisite for forming a database maintenance or help view?

If more than one table if used then there should exist a primary

foreign key relationship between them.


Can we give a condition while forming a view?

Yes in the selection criteria tab.


What is a search helps?

A search help is an object of the ABAP Dictionary with which input helps (F4 helps) can be defined.


What are types of search helps?

a) Elementary search helps implement a search path for determining the possible entries.

b) Collective search helps contain several elementary search helps. A collective search help therefore provides several alternative search paths for possible entries.

c) Append search helps can be used to enhance collective search helps delivered by SAP with customer-specific search paths without requiring a modification.


What is a Lock Object?

A lock object is a virtual link of several SAP tables which is used to synchronize simultaneous access by two users to the same set of data.


What are modes of locks?

a) Read lock (sharedlock)
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.

b) 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.

c) Enhanced write lock (exclusive lock without cumulation)
Works like a write lock except that the enhanced write lock also protects from further accesses from the same transaction.


What is a table?

a) One that stores data at run time,

b) Should be client dependent,

c) Should have primary key associated with it.


What are types of tables?

a) Transparent Tables that we create normally are transparent tables.

b) Pooled tables can be used to store control data (e.g. screen sequences, program parameters or temporary data).

c) Clustered tables contain continuous text, for example, documentation.


What does client dependent mean?

When client field MANDT is associated with any object in sap then that object becomes client dependent.


What is a primary key?

Field on which a record can be uniquely identified in a data base table is called a primary key.


Can a table contain more than one field as primary key?

Yes, In that case the group of key field form a composite primary key.


What does technical setting contain?

The technical settings of a table define how the table will be handled when it is created in the database, that is whether the table will be buffered and whether changes to data records of the table will be logged.

a) Data class: The data class defines the physical area of the database (table space) in which the table should be created.

b) Size category: The size category defines the size of the extents created for the table.


What are secondary indexes and how are they created?

When a records is searched based on other primary key then the performance is hit badly so secondary key is formed which has group of field on which we can create a index for searching. There is a button called indexes which is used to create secondary key.


What is a append structure and Include?

a) Append Structure: An append structure is a structure that is assigned to exactly one table or structure. There can be more than one append structure for a table or structure. These should always start with YY or ZZ.

b) Include Structure: They are simple structure like append structures except that they are global and can be included in any tables. And can be included more than once in the same table.


What is a structure?

Is very similarly to a table except that it does not hold any data we can say its just a definition that carried fields and their declaration.


What is the difference between a structure and table?

a) Table Hold data at runtime structure do not.

b) Tables have keys associated with it structure do not.


What is a table type?

A table type describes the structure and functional attributes of an internal table in an ABAP program


What is type group?

IT contains all the definition for variable, tables, work areas which can be used in programs.


What are the different TCODES for accessing a data dictionary?

SE11: Change, Display and create

SE12:Display only

SE16:Table Display

SE17:General Table Display


What is the CURR and CUKY significance?

Sap provides the provision for making currency as country independent value so instead of specifying the values sap also make it mandatory to give a currency type reference to the field so that conversion can be handled easily.

Same applies for QUANT and UNIT type field also.


What are different approaches for creating a table?

Top Down and Bottom Up approach.


Can we modify standard tables?

Yes, But it is not recommended. We need the access key for this.


What is foreign key relationship?

A foreign key links two tables T1 and T2 by assigning fields of table T1 to the primary key fields of table T2. Table T1 is called the foreign key table (dependent table) and table T2 the check table (referenced table).

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