What is normalization and what are the different forms of
normalizations?
Answer Posted / swapna
Normalization is the process of efficiently organizing data
in a database. There are two goals of the normalization
process: eliminate redundant data (for example, storing the
same data in more than one table) and ensure data
dependencies make sense (only storing related data in a
table). Both of these are worthy goals as they reduce the
amount of space a database consumes and ensure that data is
logically stored.
First normal form (1NF) sets the very basic rules for an
organized database:
? Eliminate duplicative columns from the same table.
? Create separate tables for each group of related data and
identify each row with a unique column or set of columns
(the primary key).
Second normal form (2NF) further addresses the concept of
removing duplicative data:
? Meet all the requirements of the first normal form.
? Remove subsets of data that apply to multiple rows of a
table and place them in separate tables.
? Create relationships between these new tables and their
predecessors through the use of foreign keys.
Third normal form (3NF) goes one large step further:
? Meet all the requirements of the second normal form.
? Remove columns that are not dependent upon the primary
key.
Finally, fourth normal form (4NF) has one additional
requirement:
? Meet all the requirements of the third normal form.
? A relation is in 4NF if it has no multi-valued
dependencies
| Is This Answer Correct ? | 28 Yes | 3 No |
Post New Answer View All Answers
What is a mutating table error and how can you get around it?
Which data types generate inaccurate results if used with an = or <> comparison in a where clause of a sql statement?
do you know what is a deadlock and what is a live lock? How will you go about resolving deadlocks? : Sql server database administration
Why can there be only one clustered index and not more than one?
Explain the cursor lock types?
What is the process of normalising?
Define inner join in sql server joins?
How to how to convert numeric expression data types using the convert() function??
What is scheduled job and how to create it?
How to replace given values with null using nullif()?
What are temporal tables in sql server 2016?
How to convert numeric expression data types by assignment operations?
What are the extra roles available in msdb? : sql server security
Explain the difference between cross join and full outer join?
What is the main difference between ‘between’ and ‘in’ condition operators?