What is POOL & CLUSTER Tables

[Former Member]

Dear ABAPers,

What is Mean by Pool and Cluster Tables.What ia the Difference between pool table and Cluster Tables.How these Tables Differs from Transparent Tables.

Thanks & Regards,

Ashok.

[Former Member]

Hi Ashok,

A pool table has many to one relation with the table in the database. For one table in the database there are many tables in the dictionary. Tha table in the database has a diff name than in the table in the data dict, it has diff no of fields and field names are different. A pooled table is stored in the pool at the database level. A table pool is a databse table with a special struct that enables the data of many R3 tables to be stored in it. It can hold only pooled tables

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

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

thanks.

[Former Member]

Hi Ashok,

Search the treads lot of help is avaialble.

Go through below link:

<a href="https://forums.sdn.sap.com/click.jspa?searchID=3487661&messageID=2279098">https://forums.sdn.sap.com/click.jspa?searchID=3487661&messageID=2279098</a>

Reward if useful!

[Former Member]

Hi ashok

Pooled tables 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.

A001,A004,A005,A006,A007,A009,A010,A012,A015,A016,A017,A018,A019,A021,A022,

Cluster tables 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.

AUAA,AUAB,AUAO,AUAS,AUAT,AUAV,AUAW,AUAY,BSEC,BSED,BSEG,BSES,BSET,CDPOS

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

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regards abhi

[Former Member]

What is transparent, cluster and pool table? Where and when we use these tables?

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

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.

Could anyone tell me what is 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.

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.

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[Former Member]

Hi,

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

Regards