ABAPDICITONARY

[Former Member]

what are cluster,transparent and pooled tables and difference of them?

[Former Member]

what are cluster,transparent and pooled tables and difference of them?

[Former Member]

Hi,

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.

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.

Regards,

Shiva Kumar

[former_member195383]

Hi ..

Please refer to the below link...

http://help.sap.com/saphelp_46c/helpdata/EN/81/415d363640933fe10000009b38f839/frameset.htm

[Former Member]

hi,

Please go through the link for the differences between pooled , cluster and transport tables.

http://help.sap.com/saphelp_nw04/helpdata/en/81/415d363640933fe10000009b38f839/frameset.htm

Trust it helps.

Reward if helpful.

Warm Regards

R Adarsh

[former_member206377]

Hi ,

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.

Transparent Table : It is an implenentation of database table in the application layer.

Also, Refer to the following links,

https://forums.sdn.sap.com/click.jspa?searchID=597044&messageID=1688508

https://forums.sdn.sap.com/click.jspa?searchID=597044&messageID=1575643

https://forums.sdn.sap.com/click.jspa?searchID=597044&messageID=1379320

https://forums.sdn.sap.com/click.jspa?searchID=597044&messageID=632928

Regards,

Vasuki

[Former Member]

Hi,

pls find sm info here.

http://www.saptechies.com/the-different-types-of-sap-tables-2/

help.sap.com

regards,

teja.

[Former Member]

Table pools (pools) and table clusters (clusters) are special table types in the ABAP Dictionary. The data from several different tables can be stored together in a table pool or table cluster. Tables assigned to a table pool or table cluster are referred to as pooled tables or cluster tables.

A table pool or table cluster should be used exclusively for storing internal control information (screen sequences, program parameters, temporary data, continuous texts such as documentation). Data of commercial relevance is usually stored in transparent tables.

BSEG is a Cluster Table. You can view that and understand better.

Reward points if useful

Regards

Sumit Agarwal

[Former Member]

A transparent table in the dictionary has a one-to-one relationship with a table in the database. Its structure in R/3 Data Dictionary corresponds to a single database table. For each transparent table definition in the dictionary, there is one associated table in the database. The database table has the same name, the same number of fields, and the fields have the same names as the R/3 table definition. When looking at the definition of an R/3 transparent table, it might seem like you are looking at the database table itself.

Transparent tables are much more common than pooled or cluster tables. They are used to hold application data.

A pooled table in R/3 has a many-to-one relationship with a table in the database. For one table in the database, there are many tables in the R/3 Data Dictionary. The table in the database has a different name than the tables in the DDIC, it has a different number of fields, and the fields have different names as well. Pooled tables are an SAP proprietary construct.

A cluster table is similar to a pooled table. It has a many-to-one relationship with a table in the database. Many cluster tables are stored in a single table in the database called a table cluster.

They would be used when these tables have a part of their primary keys in common, and if the data in these tables are all accessed simultaneously.

Table clusters contain fewer tables than table pools and, unlike table pools, the primary key of each table within the table cluster begins with the same field or fields. Rows from the cluster tables are combined into a single row in the table cluster. The rows are combined based on the part of the primary key they have in common. Thus, when a row is read from any one of the tables in the cluster, all related rows in all cluster tables are also retrieved, but only a single I/O is needed.

A cluster is advantageous in the case where data is accessed from multiple tables simultaneously and those tables have at least one of their primary key fields in common. Cluster tables reduce the number of database reads and thereby improve performance.

[Former Member]

Hi,

check this link

https://www.sdn.sap.com/irj/sdn/forums

Thanks

Nayan

[Former Member]

HI,

Check this

http://bwfreak.com/joomla/index.php?option=com_content&task=view&id=82&Itemid=1

http://help.sap.com/erp2005_ehp_03/helpdata/EN/cf/21f0b7446011d189700000e8322d00/frameset.htm

https://forums.sdn.sap.com/click.jspa?searchID=597044&messageID=1688508

https://forums.sdn.sap.com/click.jspa?searchID=597044&messageID=1575643

Hope it helps.

Assign points if helpful

Regards,

Amit

Edited by: Amit Kotwani on Jun 24, 2008 11:06 AM

[Former Member]

Hi,

check this link:

http://www.allinterview.com/showanswers/20285.html

Regards.

[Former Member]

Pool and cluster tables are differentiated by the fact that several tables logically defined in ABAP dictionary are combined in a physical database table

CLUSTER TABLE => The idea of cluster table is that you store functionally dependent data which is divided among different tables in one database table. Accordingly, the intersection of the key fields of the cluster tables is formed by

the key of the table called cluster key.

The data dependent on one cluster key are stored in the VARDATA field of the table cluster. If the VARDATA field does not have the capacity to take on all dependent data, the database interface creates on overflow record. The uniqueness within the table cluster is guaranteed by the PAGENO field.

POOL TABLES => The basic idea of pool tables is opposite to that of cluster table, i.e the storage of data records from the tables defined in the ABAP dictionary that are not dependent on one another(Combining Small R/3 tables to a database table.

[Former Member]

thanx for replying for the question