The logical term table denotes primary data, including data in columns of type LONG and data in secondary key structures.
· As specified by its schema definition, a table has exactly one B* tree for the primary data, and exactly one B* tree for each secondary key.
· If the table definition contains columns of data type LONG, an additional B* tree is created to accommodate all data of this type that does not exceed a specified length (data of type short LONG). Data items of type LONG that exceed this specific length are each stored in separate B* trees (data of type long LONG).
All searches and changes in the table are executed in the computer’s main memory via SQL statements (SELECT, INSERT, UPDATE, DELETE,...), which means that they are carried out very quickly. The B* tree structure changes itself for INSERT, UPDATE and DELETE statements only when there is not enough space in the target page for the new information, or when the fill level of a page falls below the predefined fill level.
See also: B* Trees for Tables and Table Access Using a B* Tree