topic Re: cluster,pooled tables in Application Development and Automation Discussions

cluster,pooled tables

Former Member — Mon, 22 May 2006 13:50:24 GMT

Hi all,

What is the difference of Cluster and pooled tables.and the specific applications.do we get the need to create the pooled tables in implmentations.

u.khan.

Re: cluster,pooled tables

Former Member — Mon, 22 May 2006 13:52:54 GMT

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,

Ravi

Re: cluster,pooled tables

Former Member — Mon, 22 May 2006 13:53:10 GMT

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

We generally donot get such requirement i.e, Creation of Pooled Tables

Regards,

Santosh

Re: cluster,pooled tables

Former Member — Mon, 22 May 2006 13:53:42 GMT

check this.

Regards

Laxmi

Re: cluster,pooled tables

Former Member — Mon, 22 May 2006 13:55:23 GMT

Hi,

U can also go through these links.

They might be useful

Regards,

Suruchi

Re: cluster,pooled tables

rahulkavuri — Mon, 22 May 2006 13:56:30 GMT

Pooled Table:

Cluster Table:

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.

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.

For ur Reference :

Re: cluster,pooled tables

Former Member — Mon, 22 May 2006 14:00:40 GMT

Hi ubedulla,

check this link:

http://www.sappoint.com/faq/faqabdic.pdf

regards,

keerthi.

Re: cluster,pooled tables

Former Member — Mon, 22 May 2006 14:05:47 GMT

Hai

Pooled tables. Pooled tables in the dictionary has a many-to-one relation with the table in database. Table in the database has the different name as in the dictionary. Pooled table are stored in table pool at the database level.

Several logical data records from different cluster tables can be stored together in one physical record in a table cluster.

A cluster key consists of a series of freely definable key fields and a field (Pageno) for distinguishing continuation records. A cluster also contains a long field (Vardata) that contains the contents of the data fields of the cluster tables for this key. If the data does not fit into the long field, continuation records are created. Control information on the structure of the data string is still written at the beginning of the Vardata field. A table cluster has the following structure:

Field

Data type

Meaning

CLKEY1

First key field

CLKEY2

Second key field

...

CLKEYn

nth key field

Pageno

INT2(5)

Number of the continuation record

Timestamp

CHAR(14)

Time stamps

Pagelg

INT2(5)

Length of the string in Vardata

Vardata

RAW (n)

Contains the entries from the data fields of the assigned cluster tables as a string, max. length n depends on the database system used

Cluster Tables

The records of all cluster tables with the same key are stored under one key in the assigned table cluster. The values of the key fields are stored in the corresponding key fields of the table cluster. The values of all data fields of the assigned cluster tables are written as a string to the Vardata field of the table cluster. Besides the actual data values, the data string contains information on the structure of the data and which table it comes from. If the string exceeds the maximum length of the Vardata field, a continuation record is written with the same key values. The continuation records for a key are distinguished by their value in field Pageno. The actual length of the string in the Vardata field is stored in the Pagelg field by the database interface.

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.

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.

Go through the following Link

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

Thanks & regards

Sreenivasulu P