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Background documentation Data Management Using B* Trees Locate the document in its SAP Library structure

The MaxDB data management architecture ensures efficient data storage on disks and fast data access. The database system performs automatic load balancing, which makes reorganizations unnecessary. The data area can be extended online.

Structures and algorithms are available that are required for realizing an efficient I/O strategy, and that make reorganizations unnecessary. The data management algorithms have the following characteristics:

·        Sort data on SELECT (see Table Access (SELECT) Using a B* Tree)

·        Sort data on INSERT (see Table Access (INSERT) Using a B* Tree)

·        UPDATE data in place (see Table Access (UPDATE) Using a B* Tree)

·        DELETE data in place (see Table Access (DELETE) Using a B* Tree)

For this data management, the database system uses the following logical storage structures:

·        Primary tables (with primary keys and secondary keys)

·        Secondary key tables (data of the secondary keys)

·        B* tree

B* trees are created for the following tables (see B* Trees for Tables): Primary tables and secondary key tables.

For tables with LONG columns (data type LONG, also known as BLOBs = Binary Large Objects), a special data processing procedure takes place by using the B* trees.

 

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