Fujitsu UDS/SQL V2.5 Manuel D’Utilisation

Database design

U929-J-Z125-9-76

  

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To define the physical data structure, you use the SSL (Storage Structure Language). 

The SSL is used to specify mainly: 

–

set information 

–

data placement 

–

optimization 

–

links: internal tables, chains, lists. 

The data is essentially distributed over database areas via the SSL, taking the following 
aspects into account:

–

depending on access frequency, 

–

according to physical storage options (disk capacity) and 

–

according to the backup procedures used. 

With the subschema DDL, the user selects sections from the database which are required 
for a particular application. 

For a detailed description of the subschema DDL, see 

. 

A relational schema is used in an SQL application. A relational schema is the relational view 
of an actual subschema. Such a view can be derived from a subschema with the aid of the 
utility BPSQLSIA. 

For further information on the relational schema, see 

.