Hi,
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. Control information on the structure of the data string is
still written at the beginning of the Vardata field.
The records of all cluster tables with the same key are stored under one key in the assigned table cluster. The values of the key fields are stored in the corresponding key fields of the table cluster.The values of all data fields of the assigned cluster tables are written as a string to the Vardata field of the table cluster. Besides the actual data values, the data string contains information on the structure of the data and which table it comes from. If the string exceeds the maximum length
of the Vardata field, a continuation record is written with the same key values. The continuation records for a key are distinguished by their value in field Pageno. The actual length of the string in the Vardata field is stored in the Pagelg field by the database interface.
You need the structural information stored in the ABAP Dictionary to read the data from a pooled
table or cluster table correctly. These tables can therefore only be processed using Open SQL
with the cluster interface, and not with Native SQL directly in the database.
refer link.
Regards,
Priyanka.
Bluesky
