Skip to Content
avatar image
Former Member

Abap

Hi

what are the abap dictionary in R/3 System?

What is mean by Pool table , cluser table , trans table?

what is view ? type ..

what is data type, domain, search help, lock object?

Thanks

Add comment
10|10000 characters needed characters exceeded

  • Get RSS Feed

6 Answers

  • avatar image
    Former Member
    Oct 10, 2007 at 11:34 AM
    Add comment
    10|10000 characters needed characters exceeded

  • avatar image
    Former Member
    Oct 10, 2007 at 11:35 AM

    hi,

    Data definitions (metadata) are created and managed in the ABAP Dictionary. The ABAP Dictionary permits a central description of all the data used in the system without redundancies. New or modified information is automatically provided for all the system components. This ensures data integrity, data consistency and data security.

    You can create the corresponding objects (tables or views) in the underlying relational database using these data definitions. The ABAP Dictionary therefore describes the logical structure of the objects used in application development and shows how they are mapped to the underlying relational database in tables or views.

    The ABAP Dictionary also provides standard functions for editing fields on the screen, for example for assigning a screen field an input help.

    Tables are defined in the ABAP Dictionary independently of the database. A table having the same structure is then created from this table definition in the underlying database.

    Views are logical views on more than one table. The structure of the view is defined in the ABAP Dictionary. A view on the database can then be created from this structure.

    Different fields having the same technical type can be combined in domains. A domain defines the value range of all table fields and structure components that refer to this domain.

    reward if useful.

    Message was edited by:

    ritika malhotra

    Add comment
    10|10000 characters needed characters exceeded

  • avatar image
    Former Member
    Oct 10, 2007 at 11:40 AM

    HI

    <b>ABAP Dictionary</b> – central information base for developers, containing application-specific data.

    <b>The Different Types of SAP Tables</b>

    What is transparent, cluster and pool table? Where and when we use these tables?

    Transparent Table : Exists with the same structure both in dictionary as well as in database exactly with the same data and fields.

    Pooled Table : Pooled tables are logical tables that must be assigned to a table pool when they are defined. Pooled tables are used to store control data. Several pooled tables can be cominied in a table pool. The data of these pooled tables are then sorted in a common table in the database.

    Cluster Table : Cluster tables are logical tables that must be assigned to a table cluster when they are defined. Cluster tables can be used to strore control data. They can also be used to store temporary data or texts, such as documentation.

    Could anyone tell me what is the major difference between Standard tables, Pooled tables and Clusterd Tables?

    A transparent table is a table that stores data directly. You can read these tables directly on the database from outside SAP with for instance an SQL statement.

    Transparent table is a one to one relation table i.e. when you create one transparent table then exactly same table will create in data base and if is basically used to store transaction data.

    A clustered and a pooled table cannot be read from outside SAP because certain data are clustered and pooled in one field.

    One of the possible reasons is for instance that their content can be variable in length and build up. Database manipulations in Abap are limited as well.

    But pool and cluster table is a many to one relationship table. This means many pool table store in a database table which is know as table pool.

    All the pool table stored table in table pool does not need to have any foreign key relationship but in the case of cluster table it is must. And pool and cluster table is basically use to store application data.

    Table pool can contain 10 to 1000 small pool table which has 10 to 100 records. But cluster table can contain very big but few (1 to 10) cluster table.

    For pool and cluster table you can create secondary index and you can use select distinct, group for pool and cluster table. You can use native SQL statement for pool and cluster table.

    A structure is a table without data. It is only filled by program logic at the moment it is needed starting from tables.

    A view is a way of looking at the contents of tables. It only contains the combination of the tables at the basis and the way the data needs to be represented. You actually call directly upon the underlying tables.

    <b>Importance/Use of Views</b>

    Data for an application object is often distributed on several database tables. Database systems therefore provide you with a way of defining application-specific views on the data contained in several tables. These are called views.

    Data from several tables can be combined in a meaningful way using a view (join). You can also hide information that is of no interest to you (projection) or only display those data records that satisfy certain conditions (selection).

    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.

    The data of a view can be displayed exactly like the data of a table in the extended table maintenance.

    <b>Data elements:</b> Describe an elementary type by defining the data type, length and possibly decimal places.

    The basic objects for defining data in the ABAP Dictionary are tables, data elements and domains. The domain is used for the technical definition of a table field (for example field type and length) and the data element is used for the semantic definition (for example short description).

    A domain describes the value range of a field. It is defined by its data type and length. The value range can be limited by specifying fixed values.

    A data element describes the meaning of a domain in a certain business context. It contains primarily the field help (F1 documentation) and the field labels in the screen.

    A field is not an independent object. It is table-dependent and can only be maintained within a table.

    You can enter the data type and number of places directly for a field. No data element is required in this case. Instead the data type and number of places is defined by specifying a direct type.

    The data type attributes of a data element can also be defined by specifying a built-in type, where the data type and number of places is entered directly.

    <b>Standard Search Help</b>

    The input help (F4 help) is a standard function of the R/3 System. It permits the user to display a list of possible values for a screen field. A value can be directly copied to an input field by list selection.

    The fields having an input help are shown in the R/3 System by the input help key to the right of the field. This key appears as soon as the cursor is positioned on the corresponding screen field. The help can be started either by clicking on this screen element or with function key F4.

    If the number of possible entries for a field is very large, you can limit the set of displayed values by entering further restrictions.

    Further meaningful information about the displayed values is included in the display of possible entries, especially if the field requires that a formal key be entered.

    <b>TYPES OF SEARCH HELPS</b>

    Elementary search helps

    Describe a search path. The elementary search help must define where the data of the hit list should be read from (selection method), how the exchange of values between the screen template and selection method is implemented (interface of the search help) and how the online input help should be defined (online behavior of the search help).

    Collective search help

    Combine several elementary search helps. A collective search help thus can offer several alternative search paths.

    <b>Lock Objects</b>

    SAP data dictionary provides you with a locking mechanism to synchronize simultaneous data access by different users.

    <b>Reward if usefull</b>

    Add comment
    10|10000 characters needed characters exceeded

  • avatar image
    Former Member
    Oct 10, 2007 at 11:48 AM

    ABAP Dictionary:

    The ABAP Dictionary, part of the ABAP Workbench, allows you to create and administer database tables. Open SQL contains no statements from the DDL part of Standard SQL. Normal application programs should not create or change their own database tables.

    The ABAP Dictionary uses the DDL part of Open SQL to create and change database tables. It also administers the ABAP Dictionary in the database. The ABAP Dictionary contains metadescriptions of all database tables in the R/3 System. Only database tables that you create using the ABAP Dictionary appear in the Dictionary. Open SQL statements can only access tables that exist in the ABAP Dictionary

    TYPES OF TABLES:

    Transparent Table : Exists with the same structure both in dictionary as well as in database exactly with the same data and fields.

    Pooled Table : Pooled tables are logical tables that must be assigned to a table pool when they are defined. Pooled tables are used to store control data. Several pooled tables can be cominied in a table pool. The data of these pooled tables are then sorted in a common table in the database.

    Cluster Table : Cluster tables are logical tables that must be assigned to a table cluster when they are defined. Cluster tables can be used to strore control data. They can also be used to store temporary data or texts, such as documentation.

    Add comment
    10|10000 characters needed characters exceeded

  • avatar image
    Former Member
    Oct 10, 2007 at 11:50 AM

    Some Introduction about ABAP Dictionary

    relational database in tables or views.

    The ABAP Dictionary also provides standard functions for editing fields on the screen, for example for assigning a screen field an input help.

    The descriptive data for the ABAP Dictionary is also known as meta data since is represents data about data.

    The ABAP Dictionary describes the logical structure of application development objects and their representation in the structures of the underlying relational database.

    All runtime environment components such as application programs or the database interface get information about these objects directly from the ABAP Dictionary.

    The ABAP Dictionary is an active data dictionary and is fully integrated in the ABAP Workbench.

    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

    Data definitions (metadata) are created and managed in the ABAP Dictionary. The ABAP Dictionary permits a central description of all the data used in the system without redundancies. New or modified information is automatically provided for all the system components. This ensures data integrity, data consistency and data security.

    You can create the corresponding objects (tables or views) in the underlying relational database using these data definitions. The ABAP Dictionary therefore describes the logical structure of the objects used in application development and shows how they are mapped to the underlying relational database in tables or views.

    Just have a look at these links:

    http://help.sap.com

    http://help.sap.com/saphelp_nw04/helpdata/en/cf/21f20b446011d189700000e8322d00/frameset.htm

    http://help.sap.com/saphelp_nw04/helpdata/en/cf/21f20b446011d189700000e8322d00/frameset.htm

    http://help.sap.com/saphelp_nw04/helpdata/en/00/958fb7e42b11d295f700a0c929b3c3/frameset.htm

    ********************************************

    I. Transparent tables (BKPF, VBAK, VBAP, KNA1, COEP)

    · Allows secondary indexes (SE11->Display Table->Indexes)

    · Can be buffered (SE11->Display Table->technical settings) Heavily updated tables should not be buffered.

    II. Pool Tables (match codes, look up tables)

    · Should be accessed via primary key or

    · Should be buffered (SE11->Display Table->technical settings)

    · No secondary indexes

    · Select * is Ok because all columns retrieved anyway

    III. Cluster Tables (BSEG,BSEC)

    · Should be accessed via primary key - very fast retrieval otherwise very slow

    · No secondary indexes

    · Select * is Ok because all columns retrieved anyway. Performing an operation on multiple rows is more efficient than single row operations. Therefore you still want to select into an internal table. If many rows are being selected into the internal table, you might still like to retrieve specific columns to cut down on the memory required.

    · Statistical SQL functions (SUM, AVG, MIN, MAX, etc) not supported

    · Can not be buffered

    IV. Buffered Tables (includes both Transparent & Pool Tables)

    While buffering database tables in program memory (SELECT into internal table) is generally a good idea for performance, it is not always necessary. Some tables are already buffered in memory. These are mostly configuration tables. If a table is already buffered, then a select statement against it is very fast. To determine if a table is buffered, choose the 'technical settings' soft button from the data dictionary display of a table (SE12). Pool tables should all be buffered.

    "Major difference betwen Standard tables,Pooled tables and Cluster Tables?

    1.A transparent table is a table that stores data directly. You can read these tables directly on the database from outside SAP with for instance an SQL statement.

    2.Transparent table is a one to one relation table i.e. when you create one transparent table then exactly same table will create in data base and if is basically used to store transaction data.

    3.A clustered and a pooled table cannot be read from outside SAP because certain data are clustered and pooled in one field.

    4.One of the possible reasons is for instance that their content can be variable in length and build up. Database manipulations in Abap are limited as well.

    5.But pool and cluster table is a many to one relationship table. This means many pool table store in a database table which is know as table pool.

    6.All the pool table stored table in table pool does not need to have any foreign key relationship but in the case of cluster table it is must. And pool and cluster table is basically use to store application data.

    7.Table pool can contain 10 to 1000 small pool table which has 10 to 100 records. But cluster table can contain very big but few (1 to 10) cluster table.

    8.For pool and cluster table you can create secondary index and you can use select distinct, group for pool and cluster table. You can use native SQL statement for pool and cluster table.

    9.A structure is a table without data. It is only filled by program logic at the moment it is needed starting from tables.

    10.A View is a way of looking at the contents of tables. It only contains the combination of the tables at the basis and the way the data needs to be represented. You actually call directly upon the underlying tables.

    'The table which store information about Structures and Tables are as follows:

    DD02L - table properties

    DD02T - table texts

    DD03L - field properties

    DD03T - field texts

    *****************************************************************

    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.

    In the simplest case, this derivation process can involve simply suppressing the display of one or more fields from a table (projection) or transferring only certain records from a table to the view (selection). More complicated views can be assembled from several tables, with individual tables being linked using the relational join operation.

    Use

    Logical views for the application permitting direct access to the data can be generated with the definition of view. The structure of such a view is defined by specifying the tables and fields involved in the view.

    types of view:

    PROJECTION VIEW

    DATABASE VIEW

    HELP VIEW

    MAINTENANCE VIEW

    Here are the Types of views

    Database Views:

    http://help.sap.com/saphelp_webas620/helpdata/en/cf/21ecab446011d189700000e8322d00/content.htm

    Projection View:

    http://help.sap.com/saphelp_webas620/helpdata/en/cf/21ecc5446011d189700000e8322d00/frameset.htm

    Help Views:

    http://help.sap.com/saphelp_webas620/helpdata/en/cf/21ecd2446011d189700000e8322d00/frameset.htm

    Maintenance Views:

    http://help.sap.com/saphelp_webas620/helpdata/en/cf/21ecdf446011d189700000e8322d00/frameset.htm

    ******8

    - Database View (SE11)

    Database views are implement an inner join, that is, only records of the primary table (selected via the join operation) for which the corresponding records of the secondary tables also exist are fetched. Inconsistencies between primary and secondary table could, therefore, lead to a reduced selection set.

    In database views, the join conditions can be formulated using equality relationships between any base fields. In the other types of view, they must be taken from existing foreign keys. That is, tables can only be collected in a maintenance or help view if they are linked to one another via foreign keys.

    - Help View ( SE54)

    Help views are used to output additional information when the online help system is called.

    When the F4 button is pressed for a screen field, a check is first made on whether a matchcode is defined for this field. If this is not the case, the help view is displayed in which the check table of the field is the primary table. Thus, for each table no more than one help view can be created, that is, a table can only be primary table in at most one help view.

    - Projection View

    Projection views are used to suppress or mask certain fields in a table (projection), thus minimizing the number of interfaces. This means that only the data that is actually required is exchanged when the database is accessed.

    A projection view can draw upon only one table. Selection conditions cannot be specified for projection views.

    - Maintenance View ( SE54 )

    Maintenance views enable a business-oriented approach to looking at data, while at the same time, making it possible to maintain the data involved. Data from several tables can be summarized in a maintenance view and maintained collectively via this view. That is, the data is entered via the view and then distributed to the underlying tables by the system.

    Check these links

    http://help.sap.com/saphelp_nw04/helpdata/en/cf/21ec5d446011d189700000e8322d00/content.htm

    Database views are implemented with an equivalent view on the database.

    Projection views are used to hide fields of a table (only projection).

    Help views can be used as selection method in search helps.

    Maintenance views permit you to maintain the data distributed on several tables for one application object at one time.

    *********************************************************************

    Domain and Dtatypes are objects in the DataDictionary.

    Domain Technically describes the table field, means it provide Data Type and Length of the field and it also provide Value range to the field( field holds the values only if it exisisting with in the value range) thios is also called as Value Table.

    Using Data Type object we can provide Data Element to the table field, data element provide Field Lable, assign domain, and it semeantically describes.data element acts as central object between table field and domain.

    Assuming that you want the user to maintain a table or view using SM30 but you do not want them to see the initial screen of SM30. For e.g. V023 - Material Group.

    SE93 - Type in a transaction name e.g. ZV023

    Click create - choose parameter transaction

    In the Create Parameter transaction screen, fill in the following fields :-

    Transaction SM30

    Tick Skip initial screen

    Tick Inherit GUI attributes

    Name of screen field Value

    VIEWNAME V023

    UPDATE X

    Press F8 or click the Test button for testing.

    Save it and with the required authorization, the user will be able to use transaction code ZV023 to maintain the material group.

    For brief details follow this link.

    http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb3138358411d1829f0000e829fbfe/content.htm

    **********************************************************

    search help

    1) Elementary search helps describe a search path. The elementary search help must define where the data of the hit list should be read from (selection method), how the exchange of values between the screen template and selection method is implemented (interface of the search help) and how the online input help should be defined (online behavior of the search help).

    2) Collective search helps combine several elementary search helps. A collective search help thus can offer several alternative search paths.

    3)An elementary search help defines the standard flow of an input help.

    4) A collective search help combines several elementary search helps. The user can thus choose one of several alternative search paths with a collective search help.

    5)A collective search help comprises several elementary search helps. It combines all the search paths that are meaningful for a field.

    6)Both elementary search helps and other search helps can be included in a collective search help. If other collective search helps are contained in a collective search help, they are expanded to the level of the elementary search helps when the input help is called.

    CREATION:

    Go to SE11 Tcode

    select search help

    give the 'z' search help name and create

    select the selection method ur table name eg : 'mara'

    dialog module 'display value immediately'.

    add the field whatever u want and lpos = 1 and spos = 1 and check import and export parameter.

    where left position when displaying and spos = search position

    and then save and activate ..

    See the links:

    http://help.sap.com/saphelp_nw04/helpdata/en/cf/21ee38446011d189700000e8322d00/content.htm

    http://help.sap.com/saphelp_nw04/helpdata/en/cf/21ee45446011d189700000e8322d00/content.htm

    pls go through this for search help creation

    http://help.sap.com/saphelp_nw2004s/helpdata/en/41/f6b237fec48c67e10000009b38f8cf/content.htm

    Search Help Exits:

    *****************************************************************8

    The R/3 System synchronizes simultaneous access of several users to the same data records with a lock mechanism. When interactive transactions are programmed, locks are set and released by calling function modules. These function modules are automatically generated from the definition of lock objects in the ABAP Dictionary.

    The tables in which data records should be locked with a lock request are defined in a lock object together with their key fields. When tables are selected, one table (the primary table) is first selected. Further tables (secondary tables) can also be added using foreign key relationships.

    http://help.sap.com/saphelp_nw2004s/helpdata/en/cf/21eea5446011d189700000e8322d00/content.htm

    http://help.sap.com/saphelp_nw04/helpdata/en/7b/f9813712f7434be10000009b38f8cf/content.htm

    http://www.sap-img.com/abap/type-and-uses-of-lock-objects-in-sap.htm

    Lock object name

    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 ( SAP lock concept).

    Locks are requested and released in the programming of online transactions by calling certain function modules which are automatically generated from the definition of the lock objects. These lock objects must be explicitly created in the ABAP Dictionary.

    To set locks, you must perform the following steps:

    1. You must define a lock object in the ABAP Dictionary. The name of the lock object should begin with E.

    2. The function modules for requesting and releasing locks which are created automatically when the lock object is activated must be linked to the programming of the relevant online transactions

    Add comment
    10|10000 characters needed characters exceeded

  • avatar image
    Former Member
    Oct 10, 2007 at 11:52 AM

    VIEW:

    View are logical views on more than one table. The structure of the view is defined in the ABAP Dictionary. A view on the database can then be created from this structure.

    Types are used in ABAP programs. The structure of a type can be defined globally in ABAP programs. Changes to a type automatically take effect in all the programs using the type.

    Lock object are used to synchronize access to the same data by more than one user. Function modules that can be used in application programs are generated from the definition of a lock object in the ABAP Dictionary.

    Different fields having the same technical type can be combined in domains. A domain defines the value range of all table fields and structure components that refer to this domain.

    Add comment
    10|10000 characters needed characters exceeded