Example of a Cluster Database 
Example of a Cluster Database
The database INDX is an example of a cluster database. It comes installed in the standard R/3 System, and is intended for customer use. The advantage of using this database is that you do not have to create your own. However, it does mean that all users can access, change, and delete the data that you store in it.
To display the structure of the database INDX, choose Edit ® More functions ® Enter command in the ABAP Editor, followed by SHOW INDX, or double-click INDX in a declarative statement such as TABLES.
For each field, you see the ABAP Dictionary data type and the corresponding ABAP data type (that is, the data type of the components of the table work area created using the TABLES statement).
The first four fields are the key fields of the table INDX, and correspond precisely to the description in
Structure of a Cluster Database. The third field for the cluster name has the name SRTDF and length 22 bytes. This means that <key> in the ID addition of the EXPORT statement can only contain 22 characters.The next seven fields are not standard fields. They are used for user data:
The last two fields are an obligatory part of your structure. In table INDX, the field CLUSTD, which contains the actual data clusters, has the length 2886 bytes.
For examples of table INDX in use, refer to
Saving Data Objects in Cluster Databases Creating a Directory of a Data Cluster Reading Data Objects From Cluster Databases Deleting Data Clusters from Cluster Databases