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Background documentation B* Tree Locate the document in its SAP Library structure

As far as is possible, all data in the database is stored in structures called B* trees. B* trees give much more efficient access to table rows than other access methods (such as sequential searches).

A B* tree spans several levels from the root level at the top, to the index levels, through to the lowest leaf level (one root level, n index levels (n>=1), one leaf level).

The storage units are the pages.

All subsequent comparisons in a B* tree use ASCII code (each character is assigned a numerical value between 0 and 255). The comparisons are performed for all values on a character-by-character basis.

The sort criterion for building a B* tree is the primary key.

This graphic is explained in the accompanying text

See also:

·        Root/Index Page

·        Leaf Page

·        Table Access

·        B* Trees for Tables

 

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