Record Architecture for a Relational Database Management System Supporting Null Values and Extensible Tables
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Background Information In the relational data model, a database is a collection of tables (relations). Each row (tuple) of the table contains a sequence of individual data items. All data items in a particular column of the table are of the same type (e.g., integer, character, floating point, decimal). If there is no data value for a corresponding column in the row, the data item value is said to be null. Typically, each row of the table is physically represented as a record in a data set which contains the data for one or more tables. A desirable feature of relational systems is the capability of modifying the table definition by appending columns.