Tables

Tables are logical structures maintained by the database manager. Tables are made up of columns and rows.

At the intersection of every column and row is a specific data item called a value. A column is a set of values of the same type or one of its subtypes. A row is a sequence of values arranged so that the nth value is a value of the nth column of the table.

An application program can determine the order in which the rows are populated into the table, but the actual order of rows is determined by the database manager, and typically cannot be controlled. Multidimensional clustering (MDC) provides some sense of clustering, but not actual ordering between the rows.