CIT 381 Chapter 3, Database Systems: Design, Implementation, and
Management
1. Associative Entity: See Composite Entity.
2. Attribute Domain:
3. Bridge Entity: See Composite Entity.
4. Candidate Key: A minimal superkey; that is, a key that does not contain a subset of attributes that is itself a
superkey. See key.
5. Closure: A property of relational operators that permits the use of relational algebra operators on existing tables
(relations) to produce new relations.
6. Composite Entity: An entity designed to transform an M:N relationship into two 1:M relationships. The
composite entity's primary key comprises at lease the primary keys of the entities that it connects. Also known as a
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, bridge entity or associated entity. See also Linking Table.
7. Composite Key: A multiple-attribute key.
8. Data Dictionary: A DBMS component that stores metadata- data about data. Thus, the data dictionary
contains the data definition as well as their characteristics and relationships. A data dictionary may also include data that
are external to the DBMS. Also known as an information resources dictionary. See also, Active Data Dictionary, Metadata,
and Passive Data Dictionary.
9. Dependent: An attribute whose value is determined by another attribute.
10. Determinant: Any attribute in a specific row whose value directly determines other values in that row. See
also BoyceCodd Normal Form (BCNF)
11. 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.
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Management
1. Associative Entity: See Composite Entity.
2. Attribute Domain:
3. Bridge Entity: See Composite Entity.
4. Candidate Key: A minimal superkey; that is, a key that does not contain a subset of attributes that is itself a
superkey. See key.
5. Closure: A property of relational operators that permits the use of relational algebra operators on existing tables
(relations) to produce new relations.
6. Composite Entity: An entity designed to transform an M:N relationship into two 1:M relationships. The
composite entity's primary key comprises at lease the primary keys of the entities that it connects. Also known as a
1/4
, bridge entity or associated entity. See also Linking Table.
7. Composite Key: A multiple-attribute key.
8. Data Dictionary: A DBMS component that stores metadata- data about data. Thus, the data dictionary
contains the data definition as well as their characteristics and relationships. A data dictionary may also include data that
are external to the DBMS. Also known as an information resources dictionary. See also, Active Data Dictionary, Metadata,
and Passive Data Dictionary.
9. Dependent: An attribute whose value is determined by another attribute.
10. Determinant: Any attribute in a specific row whose value directly determines other values in that row. See
also BoyceCodd Normal Form (BCNF)
11. 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.
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