Join Adam Wilbert for an in-depth discussion in this video Exploring the fourth and fifth normal form (4NF) (5NF), part of Database Foundations: Storage.
- Most database experts would say…that if all of your table satisfy the requirements…of Third Normal Form,…then you're in pretty good shape.…There are additional Normal Forms beyond Three…that deal with the Fringe problems…that can arise in the storage of complex data.…And there are important to know about,…but will be used far less often.…Fourth Normal Form says to…isolate independent multiple relationships.…That sounds a bit complex,…so let's take a look at an example.…Consider a table that has products…and their sizes and colors.…Each of the three columns combine…to create the unique identifier for the row.…
In every combination of color and size…is available in the product line.…In this case, we can move this table…into a Fourth Normal Form…and simplify the data structure…by breaking out the two independent multiple relationships.…In this case, Item and Color get put into one table…and the Item and Size go into another.…This reduces the number of cells that store data…from 18 down to 10.…Now we can still piece the original data back together…
Note: This course will also prepare certification candidates for the "Understanding data storage" domain of the Microsoft Technology Associate (MTA) Exam 98-364, Database Administration Fundamentals. Find out more at https://www.microsoft.com/learning/en-us/exam-98-364.aspx.
- Reducing redundancy with normalization
- Fixing partial dependencies
- Creating primary keys
- Linking tables with foreign keys
- Creating clustered and nonclustered indexes
Skill Level Beginner
1. Creating Normalized Tables
2. Adding Key Fields
3. Indexing Records
Adding a clustered index3m 46s
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