topic Re: tables in Application Development and Automation Discussions

tables

Former Member — Tue, 25 Apr 2006 07:43:29 GMT

hi all,

1,please tell the diffrence between pooled tables and cluster tables

Re: tables

Former Member — Tue, 25 Apr 2006 07:47:50 GMT

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

Re: tables

Former Member — Tue, 25 Apr 2006 07:49:46 GMT

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

Re: tables

Former Member — Tue, 25 Apr 2006 07:51:16 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.

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Message was edited by: Sekhar

Re: tables

Former Member — Tue, 25 Apr 2006 07:53:12 GMT

Similarities first>>

Both pool and cluster tables are like one big table in database and several small tables in application server.

And pool and cluster table is basically used to store application data.

Differences>>

The basic difference is the pool table stored table pool (at database) does not need to have any foreign key relationship but in the case of cluster table(at database) it is must.

I mean the small tables are connected with foreign keys in case of cluster table and not connected in case of pool.

regards

Alok Pathak

Re: tables

Former Member — Tue, 25 Apr 2006 07:54:42 GMT

Hi Hazam

Pooled Tables and Cluster Tables are all stored in table pool and table cluster

these tables are mainly used for storing control informations like screen sequences, long documentation texts etc.

Table pool consists of only 4 fields viz tabname (name of pool table), key fields, datalen (contain length of texts that is stored in 4th field) and 4th one is vardata where actual data is stored

There are some restrictions on using table pool such as Name of table (pool table) should not exceed 10 charaters, all the key fields should be of char data type and length of key fields should not exceed 110 characters

THis is not the case with Table cluster

here no restriction on table name lenght, data type as well as key field length

Thanks

Re: tables

Former Member — Tue, 25 Apr 2006 08:15:30 GMT

Hi,

check the following link

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

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.

Table Pools

A table in the database in which all records from the pooled tables assigned to the table pool are stored corresponds to a table pool.

Table Clusters

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

Re: tables

Former Member — Tue, 25 Apr 2006 08:53:24 GMT

Hi,

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.

Hope this helps.

Please reward some points if it helps.

Regards,

Amit Mishra