The table category defines whether a physical table exists for the logical table description defined in the ABAP Dictionary and how the table is stored on the database.
Here are the following existing table types:
* Transparent Tables (TRANSP)
There is a physical table on the database for each transparent table. The names of the physical table and the logical table definition in the ABAP/4 Dictionary agree. All the business and application data is stored in transparent tables.
* Structure (INTTAB)
No data records exist on the database for a structure. Structures are used for the interface definition between programs or between screens and programs.
* Append Structure (APPEND)
An Append structure defines a subset of fields which belong to another table or structure but which are treated as a separate object in the correction management.
Append structures are used to support modifications.
The following table types are used for internal purposes, for example to store control data or for continuous texts:
Pooled table (POOL)
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.
Cluster table (CLUSTER)
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 category. This permits object-by-object storage or object-by-object access. In order to combine tables in clusters, at least part of the keys must agree. Several cluster tables are stored in one corresponding table on the database.
Generated view structure (VIEW)
A structure is generated for a view during activation. This structure is used as the interface for the runtime environment. It is not usually displayed in the ABAP Dictionary.