exam 3 mis150 review

Subclass

A distinct subgrouping of occurrences of an entity type, which must be represented in a data model.

Superclass

Is an entity type that includes one or more distinct subgroupings of its occurrence, which require to be represented in a data model.

Mandatory Access Control (MAC)

Is based on system-wide policies that cannot be changed by individual users.

Candidate Key

The minimal set of attributes that uniquely identifies each occurrence of an entity type.

Attribute domain

The set of allowable values for one or more attributes.

First Normal Form (1NF)

A relation in which the intersections of each row and column contains one and only one value.

Boyce-Codd Normal Form (BCNF)

A relation is in BNCF if and only if every determinant is a candidate key.

Third Normal Form (3NF)

A relation that is in first and second normal form and in which no non-primary-key attribute is transitively dependent on the primary key.

Second Normal Form (2NF)

A relation that is in first normal form and every non-primary-key attribute is fully functionally dependent on the primary key.

Relationship type

A set of meaningful associations among entity types.

Unnormalized Form (UNF)

A table that contains one or more repeating groups

Normalization

A technique for producing a set of relations with desirable properties, given the data requirements of an enterprise.

Entity occurrence

A uniquely identifiable object of an entity type.

Threat

Any situation or event, whether intentional or accidental, that may adversely affect a system and consequently the organization.

Fifth Normal Form (5NF)

Every join dependency (R1, R2,...RN) in a relation R, each projection includes a candidate key of the original relation.

Fourth Normal Form (4NF)

Every nontrivial multi-valued dependency AB, A is a candidate key of the relation.

Full Functional Dependency

Indicates that if A and B are attributes of a relation, B is fully functional dependent on A if B is functionally dependent on A, but not on any proper subset of A.

Entity type

Is a group of objects with the same properties, which are identified by the enterprise as having an independent existence.

Lossless-Join Dependency

Is a property of decomposition, which means that no spurious tuples are generated when relations are combined through a natural join operation.

Multilevel Relation

Is a relation that reveals different tuples to users with different security clearances.

Composition

Is a specific form of aggregation that represents an association between entities, where there is a strong ownership and coincidental lifetime between the "whole" and the "part."

Data Administration

Is the management of the data resource, including database planning, development, and maintenance of standards, policies and procedures, and conceptual and logical database design.

Database Administration

Is the management of the physical realization of a database system, including physical database design and implementation, setting security and integrity controls, monitoring system performance, and reorganizing the database as necessary.

Specialized

Is the process of maximizing the differences between members of an entity by identifying their distinguishing features.

Generalization

Is the process of minimizing the differences between entities by identifying their common features.

Discretionary Access Control (DAC)

Manages privileges using SQL, through the GRANT and REVOKE commands.

Integrity Constraints

Prevents data from becoming invalid, and hence fiving misleading or incorrect results.

Microsoft Office Access DBMS

Provides fours methods to secure the database including splitting the database, setting a password, trusting the disabled content, packaging, signing, and deploying the database.

Oracle DBMS

Provides two types of security measures: system security and data security.

Determinant

Refers to the attribute, or group of attributes, on the left-had side of the arrow of a functional dependency.

Aggregation

Represents a "has-a" or "is-part-of" relationship between entity types, where one represents the "whole" and the other that "part."

Multi-Valued Dependency (MVD)

Represents a dependency between attributes (A, B, and C) in a relation such that for each value of A there is a set of values of B and a set of values for C. However, the set of values for B and C are independent of each other.

View

The dynamic result of one or more relational operations operating on the base relations to produce anther relation.

Encryption

The encoding of the data by a special algorithm that renders the data unreadable by any program without the decryption key.

Database Security

The mechanism that protect the database against intentional or accidental threats.

Multiplicity

The number (or range) of possible occurrences of an entity type that may relate to a single occurrence of an associated entity type through a particular relationship.

Degree of a Relationship Type

The number of participating entity types in a relationship.

Journaling

The process of keeping and maintaining a log file of all changes made to the database to enable recovery to be undertaken effectively in the event of a failure.

Backup

The process of periodically copying of the database and log file to offline storage media.

Attribute

A property of an entity or a relationship type.

Participation Constraints

Determines whether every member in the superclass must participate as a member of a subclass.

Composite Key

A candidate key that consists of two or more attributes.

Transitive Dependency

A condition where A, B, and C are attributes of a relation such that if AB and BC, then C is transitively dependent on A via B.

Authentication

A mechanism that determines whether a user is who he or she claims to be.

Cardinality

Describes the maximum number of possible relationship occurrences for an entity participating in a given relationship type.

Functional Dependency

Describes the relationship between attributes in a relations. [Ex. If A and B are attributes of relation R, B is functionally dependent on A (donted A B), if each value of A is associated with exactly one value of B.]

Disjoint Constraints

Describes the relationship between members of the subclasses and indicates whether it is possible for a member of a superclass to be a member of one, or more than one, subclass.

Participation

Determines whether all or only some entity occurrences participate in a relationship.

Asymmetric Encryption

Uses different keys for encryption and decryption.

Symmetric Encryption

Uses the same key for both encryption and decryption and relies on safe communication lines for exchanging the key.

Redundant Array of Independent Disks (RAID)

Works on having a large disk array comprising an arrangement of several independent disks that are organized to improve reliability and at the same time increase performance.