INSY 3304 Exam 2 QUESTIONS AND
ANSWERS 100% CORRECT
Normalization - ANSWER-process of assigning attributes to the entities to which they
belong
Reduces data anomalies
Assigns attributes to tables based on determination
Goal: eliminate unnecessary redundancy
normal forms - ANSWER-1NF, 2NF, 3NF
1NF - ANSWER-Table format
No repeating groups
Primary key identified
2NF - ANSWER-Meets reqs for 1NF
No partial dependencies
3NF - ANSWER-Meets reqs for 2NF
No transitive dependencies
dependencies - ANSWER-functional
full functional
partial
transitive
Functional - ANSWER-one attribute determines another
Full Functional - ANSWER-Best dependency to have
The whole table can be determined only by the primary key
Exists if all non-key attributes are determined by the key, the whole key, and nothing but
the key
Goal of 3NF is full functional dependency
Partial - ANSWER-functional dependence in which the determinant is only part of the
primary key
Assumption: 1 candidate key
Straight forward
Easy to identify
Allowed in 1NF
Not allowed in 2NF
, Transitive - ANSWER-attribute is dependent on another attribute that is not part of
primary key
More difficult to identify
Occur when a functional dependence exists among nonprime attributes
Allowed in 1NF
Allowed in 2NF
CREATE SCHEMA AUTHORIZATON - ANSWER-ansi standard, more common is
create db
CREATE TABLE - ANSWER-creates a new table in user's db schema
ALTER TABLE - ANSWER-modifies a table's def
add columns, delete columns, add constraints
DROP TABLE - ANSWER-permanently deletes a table & its data
CREATE TABLE AS - ANSWER-creates a new table based on a query in user's db
schema
INSERT - ANSWER-inserts rows into a table
Syntax: INSERT INTO TABLE VALUES(0,'Chars',0);
SQL - ANSWER-structured query lang
Non procedural, all commands
All commands have semicolon at end
Utility functions have no semicolons
2 types of commands - ANSWER-DDL - data definition lang
DML - data manip lang
DDL - ANSWER-data definition lang
Allow u to define db
Written to disk automatically
DDL examples - ANSWER-CREATE TABLE
NOT NULL
UNIQUE
PRIMARY KEY
FOREIGN KEY
CREATE INDEX
CREATE VIEW
ALTER TABLE
DROP TABLE
DROP INDEX
ANSWERS 100% CORRECT
Normalization - ANSWER-process of assigning attributes to the entities to which they
belong
Reduces data anomalies
Assigns attributes to tables based on determination
Goal: eliminate unnecessary redundancy
normal forms - ANSWER-1NF, 2NF, 3NF
1NF - ANSWER-Table format
No repeating groups
Primary key identified
2NF - ANSWER-Meets reqs for 1NF
No partial dependencies
3NF - ANSWER-Meets reqs for 2NF
No transitive dependencies
dependencies - ANSWER-functional
full functional
partial
transitive
Functional - ANSWER-one attribute determines another
Full Functional - ANSWER-Best dependency to have
The whole table can be determined only by the primary key
Exists if all non-key attributes are determined by the key, the whole key, and nothing but
the key
Goal of 3NF is full functional dependency
Partial - ANSWER-functional dependence in which the determinant is only part of the
primary key
Assumption: 1 candidate key
Straight forward
Easy to identify
Allowed in 1NF
Not allowed in 2NF
, Transitive - ANSWER-attribute is dependent on another attribute that is not part of
primary key
More difficult to identify
Occur when a functional dependence exists among nonprime attributes
Allowed in 1NF
Allowed in 2NF
CREATE SCHEMA AUTHORIZATON - ANSWER-ansi standard, more common is
create db
CREATE TABLE - ANSWER-creates a new table in user's db schema
ALTER TABLE - ANSWER-modifies a table's def
add columns, delete columns, add constraints
DROP TABLE - ANSWER-permanently deletes a table & its data
CREATE TABLE AS - ANSWER-creates a new table based on a query in user's db
schema
INSERT - ANSWER-inserts rows into a table
Syntax: INSERT INTO TABLE VALUES(0,'Chars',0);
SQL - ANSWER-structured query lang
Non procedural, all commands
All commands have semicolon at end
Utility functions have no semicolons
2 types of commands - ANSWER-DDL - data definition lang
DML - data manip lang
DDL - ANSWER-data definition lang
Allow u to define db
Written to disk automatically
DDL examples - ANSWER-CREATE TABLE
NOT NULL
UNIQUE
PRIMARY KEY
FOREIGN KEY
CREATE INDEX
CREATE VIEW
ALTER TABLE
DROP TABLE
DROP INDEX
