Table Clusters

Dear Gurpreet,

there is different usage of the term "cluster" in the ABAP environment, which should not be mixed:

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cluster:

Grouping of different data in a shared repository.You can have either "data clusters" in various different storage media for data objects or "table clusters" for database tables ("cluster tables").

data cluster:

Data objects grouped together for the purpose of transient or

persistent storage in a memory medium of choice. A data cluster can be

processed using the IMPORT and EXPORT statements. (Those can be stored in INDX-type database tables that are not the same as "table clusters").

cluster table:

Database table defined in the ABAP Dictionary .Its instance on the database is assigned to more than 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 in the cluster tables forms the primary key of the table cluster. The other columns in the cluster tables are compressed in a

single column of the table cluster, called VARDATA.Cluster tables can be accessed only with Open SQL, and no joins can be created.

table cluster:

A database table in the database that contains data from several cluster tables.

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Following these definitions, you must use Open SQL in oder to work with a cluster table. You must look up the table's definition in the ABAP dictionary in order to find its components.

Best regards

Horst Keller

Thanks, for the answer, one more ques.

What do we mean by transparent tables of cluster tables like , bsik is to bseg.

thank you.

Regards,