Data normalization (A3.2 Database design)

0.0(0)
studied byStudied by 0 people
0.0(0)
full-widthCall Kai
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
GameKnowt Play
Card Sorting

1/5

encourage image

There's no tags or description

Looks like no tags are added yet.

Study Analytics
Name
Mastery
Learn
Test
Matching
Spaced

No study sessions yet.

6 Terms

1
New cards

Data normalization

Process of organizing data to reduce data redundancy and improve data integrity

  • = smaller tables with less info per row = v input/output/transfers = CPU can work at full capacity (v chance CPU activities being suspended)

2
New cards

I. Functional dependency

Relationship: one set of attributes (determinant) determines values of another set and table (dependent)

  • Relationship between PK attribute and non-key attribute

3
New cards

Full functional dependency (I)

Dependent attributes are COMPLETELY determined by determinant attributes

  • E.g StudentID fully determines student’s attributes

<p><span style="background-color: transparent;"><span>Dependent attributes are COMPLETELY determined by determinant attributes</span></span></p><ul><li><p><span style="background-color: transparent;"><span>E.g StudentID fully determines student’s attributes</span></span></p></li></ul><p></p>
4
New cards

Partial functional dependency (I)

Dependent attributes are PARTIALLY determined by determinant attributes

  • E.g. StudentID could partially determine STUDENTS table’s FirstName, LastName, DateOfBirth, but not course instructor or club

<p><span style="background-color: transparent;"><span>Dependent attributes are PARTIALLY determined by determinant attributes</span></span></p><ul><li><p><span style="background-color: transparent;"><span>E.g. StudentID could partially determine STUDENTS table’s FirstName, LastName, DateOfBirth, but not course instructor or club</span></span></p></li></ul><p></p>
5
New cards

Transitive dependency (I)

Dependent attributes determined by set of attributes not included in determinant attributes

  • E.g. EMPLOYEES table’s EmployeeID determines DEPARTMENTS EmployeeDepartment which determines SALARY salary

<p><span style="background-color: transparent;"><span>Dependent attributes determined by set of attributes not included in determinant attributes</span></span></p><ul><li><p><span style="background-color: transparent;"><span>E.g. EMPLOYEES table’s EmployeeID determines DEPARTMENTS EmployeeDepartment which determines SALARY salary</span></span></p></li></ul><p></p>
6
New cards

First normal form (1NF)

  • Traits: 

    • Primary key

    • No duplicate attributes from same table

    • No repeated groups of attributes

    • Data in each field must be atomic (as necessary) - attribute contains indivisible values (can’t be broken down further)

  • Create separate tables