BCNF AND 4NF

BCNF AND 4NF - Normalization Why&What 1stNormalForm...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
    Normalization 1st Normal Form 2nd Normal Form 3rd Normal Form Boyce-Codd Normal Form 4th Normal Form
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    Normalization - Why Eliminate anomalies Avoid duplication Increase flexibility and stability Reduce maintenance
Background image of page 2
    Normalization - What?!? Analysis of functional dependencies between  attributes Building several smaller tables from larger ones Decomposing relations with anomalies to  produce smaller, well-structured relations Reducing complexity & increasing stability
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    Normalization - What (2) Series of Steps Recipe for constructing a “good” physical  model of a database from a logical model Applied to all existing tables, including  ones produced by earlier normalization  steps
Background image of page 4
    Example Sales (Order# , Date, CustID, Name, Address,  City, State, Zip, {Product#, ProductDesc,  Price, QuantityOrdered}, Subtotal, Tax,  What are the problems with using a single  table for all order information? Think of it as a single spreadsheet
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    Problems Implementing Repeating Groups address) Unnecessary Data (subtotal, total, tax) Others Normalization is a process to eliminate  these problems.
Background image of page 6
    1st Normal Form Eliminate Repeating Groups 1st Normal Form has no repeating  groups Create definition with all other attributes,  remove the repeat {}, and change the  primary key to include the “key” for the  repeating group.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    Example Sales (Order# , Date, CustID, Name, Address,  City, State, Zip, Product# , ProductDesc,  Price, QuantityOrdered, Subtotal, Tax,  S&H, Total)
Background image of page 8
    2nd Normal Form Remove all partial functional 
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 37

BCNF AND 4NF - Normalization Why&What 1stNormalForm...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online