Db Chapter 4

Front 1

What are the steps for taking a table and splitting it up for use in a database?

Back 1

Follow the steps of normalization!

Front 2

How do you determine the number of rows in a database using SQL

Back 2

SELECT COUNT(*) as NumOfRows
FROM Inventory

Front 3

How do you show all columns and rows of a table using SQL?

Back 3

SELECT *
FROM Inventory

Front 4

How do you use the top/limit clause in SQL?

Back 4

SELECT *
FROM Inventory
LIMIT 10;

Front 5

What are the advantages of normalization?

Back 5

-Greater overall database organization
-Reduction of redundant data
-Data consistency within the database
-A much more flexible database design
-A better handle on database security

Front 6

What are the disadvantages of normalization?

Back 6

-It requires much more storage space.
-Requires more joins to get certain data displayed.
-More data = more tables (i.e. more work).

Front 7

Why would you denormalize a set of tables?

Back 7

To maintain a history and/or to improve performance.

Front 8

What is the multivalue, multicolumn problem?

Back 8

The number of items ends up being fixed (i.e. have columns for 3 children but someone has 4), and it presents the problem of having to write a more complicated query.

Front 9

What is a null value, and what problems does it present in database design?

Back 9

Null technically means "unknown" so it really can't be considered a value. It can present problems if a table contains mathematical operations b/c null has an unknown value and therefore you cannot complete the operation. It can also adversely effect aggregate functions like COUNT.

Front 10

What is the problem with general purpose remarks in SQL?

Back 10

They typically contain inconsistent data. What one person thinks may be very different from another or they may choose different keywords. This causes a major quandry for someone who may be writing a query.