What is the importance of normalizing a database? What types of problems are avoided?

Answer 1

normalizing a db is only important if it will help you. raw data is often more meaningful. you'll need to decide this for yourself.

Answer 2

it makes sure the data is corretly formatted and can compress the size for example with standard lookups for the words Road, street, male,femals etc it also ensures numbers dates and ages are in correct format. a date entered in american format in an english database would give the wrong results!!