regarding Table pools and Table Clusters?

[Former Member]

in database, pooled tables are stored in the Table pools,

i want to know, where we create this table pools? this is created by user ? or internally it will created ?

[Former Member]

Hi,

Even a user can create pool and cluster tables.

Procedure

In the initial screen of the ABAP Dictionary, choose Utilities ® Further Dictionary Objects.

A dialog box appears.

Select the object type Table pool/cluster and enter the object name. Choose .

A dialog box appears in which you must specify if it is a table pool or a table cluster.

Select the required object type and choose .

The maintenance screen for table pools/clusters appears.

The necessary entries will have been made automatically for the fields for table pools since a table pool has a fixed structure. You should not change these standard settings if you can avoid it.

The structure of a table cluster is also mostly fixed. Certain fields are therefore proposed when the table cluster is created. You can adjust this proposal to your requirements, for example by inserting further key fields. However, make sure you conform to the structure necessary for a table cluster.

Enter an explanatory text in the field Short text.

If necessary, select the activation type of the table pool/cluster with Utilities ® Activation type.

Create documentation about the table pool/cluster with Goto ® Documentation.

This documentation should describe what the table pool/cluster is used for. The documentation is also output when the table pool/cluster is printed.

Go to the maintenance screen for the technical settings by choosing Goto ® Technical settings.

In contrast to the table maintenance screen, you can only define the size category here. All other attributes of the technical settings are preset.

Activate the table pool/cluster with .

Regards,

Tanveer.

Please mark helpful answers

[Former Member]

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.

Check this Link to know more

Refer this link:

For help:

http://help.sap.com/saphelp_nw04/helpdata/en/cf/21f083446011d189700000e8322d00/content.htm

WE usually don't get any requirement of creating such tables in projects.

Regards,

[Former Member]

Hi Selva,

Nice question?.... Thank u.

[Former Member]

please i am no clear about the above answer, please give in detail

[Former Member]

Hi selva,

1. In sap we know that there are two things

a) ABAP Dictionary tables (just for definition purpose,

so that we can use in select statement,

and data declaration)

b) Actual physical tables in database

2. Consider one FI table like BSEG

and some other tables like

BSEC

BSED

BSEG

BSES

BSET

3. These 6 TABLES ONLY EXIST IN DATA DICTIONARY

(AND NOT IN PHYSICAL DATABASE)

(SO WE CAN DECLARE THESE TABLES IN ABAP PROGRAM)

AND ALSO USE SELECT QUERY

4. BUT FOR ALL THESE 6 TABLES,

THERE IS ONLY ONE PHYSICAL TABLE IN DATABASE.

THAT PHYSICAL TABLE IS CALLED 'TABLE POOL'

AND THE NAME IS 'RFBLG'

5. THIS physical table RFBLG

stores each record of all these six

tables in a RAW format.

6. So in abap program,

when we fire a select query on BSEG,

In REALITY, the physical database searched for is

RFBLG

regards,

amit m.

[Former Member]

HI

GOOD

I THINK THE TABLE POOLS ARE NOT CREATED BY THE USER BUT THE BASIS CONSULTANT WHO IS REPONSIBLE TO MANAGE THE DATABASE AND ITS CONFIGURATION.

THANKS

MRUTYUN