Database Management Extra 2

Question 1

A representation of the conceptual model, usually expressed graphically.

Answer 1

Conceptual Schema

Question 2

A restriction placed on data, usually expressed in the form of rules. For example, “A student’s GPA must be between 0.00 and 4.00.” Constraints are important because they help to ensure data integrity.

Answer 2

Constraint

Question 3

A representation of the entity relationship diagram that uses a three-pronged symbol to represent the “many” sides of the relationship.

Answer 3

Crow’s Foot Notation

Question 4

The language that allows a database administrator to define the database structure, schema, and subschema.

Answer 4

DDL

Question 5

The set of commands that allows an end user to manipulate the data in the database, such as SELECT, INSERT, UPDATE, DELETE, COMMIT, and ROLLBACK.

Answer 5

DML

Question 6

A representation, usually graphic, of a complex “real-world” data structure. ??? ??? are used in the database design phase of the Database Life Cycle.

Answer 6

Data Model

Question 7

One of three types of nodes used in the Hadoop Distributed File System (HDFS). The ??? ??? stores fixed-size data blocks (that could be replicated to other data nodes).

Answer 7

Data Node

Question 8

A row in a relational table.

Answer 8

entity instance / entity occurence

Question 9

A data model that describes relationships (1:1, 1:M, and M:N) among entities at the conceptual level with the help of ER diagrams. The model was developed by Peter Chen.

Answer 9

ERM

Question 10

A model for database consistency in which updates to the database will propagate through the system so that all data copies will be consistent eventually.

Answer 10

Eventual Consistency