Difference between transparent, pooled and cluster table.

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. Tables assigned to a table pool or table cluster are referred to as pooled tables or cluster tables.


Table Pools
 
 A table pool or table cluster should be used exclusively for storing internal control information (screen sequences,program parameters, temporary data, continuous texts such as documentation). Data of commercial relevance is usually stored in transparent tables.

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.

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.