cluster table&Pooled table

[Former Member]

Hi ,

please tell me the difference between cluster table and pooled table and give the example for the above table,

Thanks & Regards

Ramprasad

[anversha_s]

Hi,

<u>I. Pool Tables (match codes, look up tables)</u>

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

<u>

II. Cluster Tables (BSEG,BSEC)</u>

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

More at this link.

http://help.sap.com/saphelp_erp2004/helpdata/en/81/415d363640933fe10000009b38f839/frameset.htm

regrds,

anver

[Former Member]

Hi,

Pool table

A database table defined in the ABAP Dictionary whose database instance is assigned to more than one table defined in the ABAP Dictionary. Multiple pool tables are assigned to a table pool in the database. The key fields of a pool table have to be character-type fields. The table pool's primary key consists of two fields: TABNAME for the name of a pool table, and VARKEY for the interdependent contents of the key fields in the corresponding pool table. The non-key fields of the pool table are stored in compressed format in their own column, called VARDATA, of the table pool. The only way to access pool tables is by using Open SQL. Joins are not allowed.

Table Pool

Database table in the database that contains the data of several pool tables.

Cluster Table

Database table defined in the ABAP Dictionary, whose version on the database is not only assigned to one table defined in the ABAP Dictionary. Several cluster tables are assigned to a table cluster in the database. The intersection of the key fields of the cluster tables forms the primary key of the table cluster. The other columns of the cluster tables are stored in compressed form in a single column VARDATA of the table cluster. You can access cluster tables only via Open SQL, and only without using joins.

Table Cluster

Database table in the database that contains the data of several cluster tables.

Note: Never mix up with a database table that has the necessary structure for storing data clusters in database tables and in the shared memory. Those are called INDX-type, with reference to the database table INDX supplied by SAP. Data clusters are groupings of data objects for transient and persistent storage in a selectable storage medium. A data cluster can be processed using the statements IMPORT, EXPORT, and DELETE FROM

This link also helps you...

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

Check out these threads

EXAMPLES

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

Regards,

Priyanka.

[former_member235056]

Hi,

Have a look at the link u will get all the details u want here.

<a href="http://help.sap.com/saphelp_nw04/helpdata/en/cf/21f083446011d189700000e8322d00/content.htm">Pooled and cluster tables</a>

pls do reward points.

Regards,

Ameet

[Former Member]

Hi

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

<b>

Pooled Table :</b> 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.

<b>Cluster Table :</b> 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.

<b>difference between Standard tables, Pooled tables and Clusterd Tables</b>

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.

Go through this link

http://web.mit.edu/sapr3/dev/sap_table_types.htm

Reward points if helpful.

All the best

[Former Member]

<b>What is the difference between Clustered Tables and Pooled Tables?</b>

A pooled table is used to combine several logical tables in the ABAP/4 dictionary. Pooled tables are logical tables that must be assigned to a table pool when they are defined.

Cluster table are logical tables that must be assigned to a table cluster when they are defined.

Cluster table can be used to store control data they can also used to store temporary data or text 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.

<b>Some of List cluster tables</b>

AUAA

AUAB

AUAO

AUAS

AUAT

AUAV

AUAW

AUAY

BSEC

BSED

BSEG

BSES

BSET

CDPOS

<b>Some of list Pooled tables </b>

A001

A004

A005

A006

A007

A009

A010

A012

A015

A016

A017

A018

A019

A021

A022

A023

A024

A025

A026

A028

A030

A032

A044

A045

A046

A047

A049

A051

A052

A053

A054

A058

A059

A060

A061

A062

A063

A400

A401

reward points if it is usefull ...

Girish

[Former Member]

Hi,

I think you got the differences b/n pooled and cluster tables. Now i will tell you how u can see the pool,cluster,tranparent and internal tables in sap.

goto SE!!

Type DD02L.

click Display button

Then press F8.

then in Table Category field Press F4 .

You will get the list of tables n then select any table you want and press F8.

you can see number of pool,cluster,trans,int tables in SAP.

Reward if helpful.

Regards

Raghavendra.D.S

[Former Member]

Hi,

I. 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

II. 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