C170 Data Management Application RATED A+

AREA - In DB2, a named section of permanent storage space that is reserved to store the database. associative entity - See composite entity. bridge entity - See composite entity. candidate key - A minimal superkey; that is, a key that does not contain a subset of attributes that is itself a superkey. See key. closure - A property of relational operators that permits the use of relational algebra operators on existing tables (relations) to produce new relations. composite entity - An entity designed to transform an M:N relationship into two 1:M relationships. The composite entity's primary key comprises at least the primary keys of the entities that it connects. Also known as a bridge entity or associative entity. See also linking table. composite key - A multiple-attribute key. dependent - An attribute whose value is determined by another attribute. determination - The role of a key. In the context of a database table, the statement "A determines B" indicates that knowing the value of attribute A means that the value of attribute B can be looked up. DIFFERENCE - In relational algebra, an operator used to yield all rows from one table that are not found in another union-compatible table.