Lesson 4 - Normalization Flashcards
are a set of rules. It is used to maintain the quality of information.
Integrity Constraints
- ensure that the data insertion, updating, and other processes have to be performed in such a way that data integrity is not affected.
- used to guard against accidental damage to the database.
Integrity Constraints
can be defined as the definition of a valid set of values for an attribute.
Domain Constraints
The data type of this constraint includes string, character, integer, time, date, currency, etc. The value of the attribute must be available in the corresponding of this.
Domain
The _______ ______ constraint states that primary key value can’t be null
Entity Integrity Constraint
A table can contain a null value other than the primary key field.
True
This constraint is specified between two tables.
Referential Integrity Constraint
____are the entity set that is used to identify an entity within its entity set uniquely.
Keys
In the __________ constraints, if a foreign key in Table 1 refers to the Primary Key of Table 2, then every value of the Foreign Key in Table 1 must be null or be available in Table 2
Referential Integrity Constraints
a relationship that exists between two attributes. It typically exists between the primary key and non-key attribute within a table.
Functional Dependency
essentially a set of rules that allows you to organize your database in such a way that your tables are related, where appropriate, and flexible for future growth and relationships.
Database Normalization
The sets of rules used in normalization are called ________
Normal Forms
a prime example of something needing to be normalized.
Flat Table
table is like a spreadsheet with many columns of data.
Flat Table
, there are no relationships between multiple table, as all the data you could possibly want is right there in that single flat table
Flat Table
is not efficient design and will consume more physical space on your hard drive than a set of normalized database tables.
Flat Table
What are the Normal Forms
1NF, 2NF, 3NF, Boyce-Codd Normal Form, 4NF, 5NF
- Ensure that all table contain single type of data (atomic data).
- Eliminate repeating information.
- Create separate tables for related data.
First Normal Form 1NF
- No non-key attributes depend on a portion of the primary key.
- All attributes should be functionally dependent on the primary key(s).
Second Normal Form
Ensures that there is no transitive dependency.
No attributes depend on other non-key attributes.
Third Normal Forms
process of organizing the data in the database.
Normalization
divides the larger table into the smaller table and links them using relationship.
Normalization
what are the integrities
Domain, entity integrity, referential integrity, key
