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 Accessing Data 

The database system uses the following logical structures to store data:

·        Primary tables (with primary key and secondary key)

·        Secondary key tables

·        B* trees

B* trees are created for primary tables and secondary key tables (B* trees for tables). For tables with LONG columns (data type LONG, also known as BLOBs = Binary Large Objects), a special data processing procedure takes place using the B* trees.

The database system balances the storage automatically, making a manual reorganization of the data unnecessary. The data area can be extended online.

The database system uses the following strategies to enable it to access data efficiently:

·        Table access (SELECT) using a B* tree

·        Table access (INSERT) using a B* tree

·        Table access (UPDATE) using a B* tree

·        Table access (DELETE) using a B* tree

 

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