Lesson 12: Maximize Database Integrity and Performance

Question 1

Constraints

Answer 1

Defined rules specified for the data in a database table

Question 2

DEFAULT Constraint

Answer 2

Used to provide a default value for a column. If no other value is specified, the default value will be added to the column in a new row.

Question 3

CHECK Column Constraint

Answer 3

Used to limit the value range that can be placed in a column. Only certain values can be added to the column.

Question 4

CHECK Table Constraint

Answer 4

A CHECK constraint on a table limits the values based on values in other columns in the row.

Question 5

NULL Constraint

Answer 5

The column default is to allow NULL values. A row can be added to the table without a value in the column.

Question 6

NOT NULL Constraint

Answer 6

A rule that enforces a column to not accept NULL values. A row cannot be added to the table without a value in the column.

Question 7

Primary Key (PK) Constraint

Answer 7

The unique column in a table.

Question 8

Index

Answer 8

An index is used to help the query process performance when retrieving data.