Re : what is Diffrent Between ClusterTable and poolTable ?

[Former Member]

Hi ,

What is Exctaly diffrent Between Clustertable and poolTable pls let me know......

Kind Regards

Arief .S

[Former Member]

Hi ,

What is Exctaly diffrent Between Clustertable and poolTable pls let me know......

Kind Regards

Arief .S

[Former Member]

Hi Arief,

<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 combined in a table pool.

The data of these pooled tables are then sorted in a common table in the database.

(e.g. screen sequences, program parameters or temporary data.. )

<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.

eg : chk this table PCL1 - HR related data

also, you can check the following threads for more examples & explanations:

best regards,

Thangesh

[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.

regards

aswin

[Former Member]

hi...

cluster table :

A cluster table has many to 1 relationship...

A few tables in the R/3 DDIC .. but only one table in DATABASE...

And i think cluster tables shud have atleast one primary key in common

Cluster table are much more complex and you cannot display the data of a cluster table directly....

Cluster table have to be read and displayed via your ABAP program...

To find the cluster behind a cluster table, just go to the attributes of the table.

or go thro these information i got abt cluster table.

A table cluster is used to combine several tables. In the process several lines from different tables are combined in a single record. The records of all tables combined in a table cluster are stored in one table in the database.

A cluster contains a transparent cluster key which must be the first part of the key of all tables assigned to the cluster.

A table cluster also has a long field which contains the data from the tables on this key. If the data does not fit into this field, continuation records are created.

[Former Member]

hi..

pool table :

(i found these details by searching the net)

The definition of a pool consists essentially of two key fields (Tabname and Varkey) and a long argument field (Vardata).

Example : Pool table : MDTC

example for cluster table:

BSEG is a cluster table consisting data from tables

BSID,BSAD,BSIS,BSAS,BSIK,BSAK which all are transperent tables.

reward points if u find my asnwers useful...

all the best.

[Former Member]

<b>Pooled Tables:</b>

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.

When you look at a pooled table in R/3, you see a description of a table. However, in the database, it is stored along with other pooled tables in a single table called a table pool. A table pool is a database table with a special structure that enables the data of many R/3 tables to be stored within it. It can only hold pooled tables.

R/3 uses table pools to hold a large number (tens to thousands) of very small tables (about 10 to 100 rows each). Table pools reduce the amount of database resources needed when many small tables have to be open at the same time. SAP uses them for system data. You might create a table pool if you need to create hundreds of small tables that each hold only a few rows of data. To implement these small tables as pooled tables, you first create the definition of a table pool in R/3 to hold them all. When activated, an associated single table (the table pool) will be created in the database. You can then define pooled tables within R/3 and assign them all to your table pool.

Pooled tables are primarily used by SAP to hold customizing data.

<b>Cluster Tables:</b>

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.

A table cluster is similar to a table pool. It holds many tables within it. The tables it holds are all cluster tables.

Like pooled tables, cluster tables are another proprietary SAP construct. They are used to hold data from a few (approximately 2 to 10) very large tables. 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.

Restrictions on Pooled and Cluster Tables

Pooled and cluster tables are usually used only by SAP and not used by customers, probably because of the proprietary format of these tables within the database and because of technical restrictions placed upon their use within ABAP/4 programs. On a pooled or cluster table:

- Secondary indexes cannot be created.

- You cannot use the ABAP/4 constructs select distinct or group by.

- You cannot use native SQL.

- You cannot specify field names after the order by clause. order by primary key is the only permitted variation.

I hope it helps.

Best Regards,

Vibha

*Please mark all the helpful answers

[Former Member]

Hi ,

1)What is Exctaly diffrent Between Clustertable and poolTable pls let me know......

The data from several tables is 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.

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.

Just go through these links:

<a href="http://help.sap.com/saphelp_nw04/helpdata/en/cf/21eb13446011d189700000e8322d00/frameset.htm">http://help.sap.com/saphelp_nw04/helpdata/en/cf/21eb13446011d189700000e8322d00/frameset.htm</a>

<a href="http://help.sap.com/saphelp_nw04/helpdata/en/81/415d363640933fe10000009b38f839/frameset.htm">http://help.sap.com/saphelp_nw04/helpdata/en/81/415d363640933fe10000009b38f839/frameset.htm</a>

Regards,

Gunasree.

Please award points to helpful answers.

[Former Member]

hi...

even this information i found by searching the net... check out n reward if useful.

<b>Pooled tables</b> can be used to store control data (e.g. screen sequences, program parameters or temporary data). Several pooled tables can be combined to form a table pool. The table pool corresponds to a physical table on the database in which all the records of the allocated pooled tables are stored.

examples:

A001

A004

A005

A006

A007

A009

A010

A012

A015

A016

A017

A018

A019

A021

A022

<b>Cluster tables</b> contain continuous text, for example, documentation. Several cluster tables can be combined to form a table cluster. Several logical lines of different tables are combined to form a physical record in this table type. This permits object-by-object storage or object-by-object access. In order to combine tables in clusters, at least parts of the keys must agree. Several cluster tables are stored in one corresponding table on the database.

examples :

AUAA

AUAB

AUAO

AUAS

AUAT

AUAV

AUAW

AUAY

BSEC

BSED

BSEG

BSES

BSET

CDPOS

all the best.