What is normalization? Explain different levels of
normalization?
Answer Posted / a.mohan kumar
To avoid redundancy and to constructing an efficient
database we use normalization.its a concept which is used to
construct efficient database .the types of normalization are:
First Normal form (1NF): A relation is said to be in 1NF if
it has only single valued attributes, neither repeating nor
arrays are permitted.
Second Normal Form (2NF): A relation is said to be in 2NF if
it is in 1NF and every non key attribute is fully functional
dependent on the primary
key.
Third Normal Form (3NF): We say that a relation is in 3NF if
it is in 2NF and has no transitive dependencies.
Boyce-Codd Normal Form (BCNF): A relation is said to be in
BCNF if and only if every determinant in the relation is a
candidate key.
Fourth Normal Form (4NF): A relation is said to be in 4NF if
it is in BCNF and contains no multi valued attributes.
Fifth Normal Form (5NF): A relation is said to be in 5NF if
and only if every join dependency in relation is implied by
the candidate keys of relation.
Domain-Key Normal Form (DKNF): We say that a relation is in
DKNF if it is free of all modification anomalies. Insertion,
Deletion, and update anomalies come under modification
anomalies.
om Namasivaya.
| Is This Answer Correct ? | 41 Yes | 7 No |
Post New Answer View All Answers
Does QTP Support the Propjects which are running in Dot Net? As we are starting with new project in Dot net need to use automation tool?Please advice & let me know what would be the best.
Explain about query and reporting.
The count() function always returns a int value type what should you do if you need to count rows from a query which you know will return a value that is too large for an int value type?
Hi my program is accesing data from two db2 databases.what is the bind card for this program to genarate plan? how to specify the two owners and two qualifiers in bind card
Explain about relational operator join?
You are testing the performance of a query the first time you run the query, the performance is slow. the second time you run the query, the performance is fast. why is this?
Any sample or model question of punjab national bank for deputy manger IT or any sample of PNB.any1 plz do send on
Hi , any one can help me on the same,this is regarding the Informatica Function doc,i want to know how developer is will develop the mapping. pl forwar the any function doc .just for my references. svlc75@yahoo.co.in
How to read and create .LDC data files which are used by linguatic dictionary.
How to replace not in with not exist?
What is the database development process?
How can you log an error to the server event log from a stored procedure?
In which database can extended stored procedures be added?
What is the physical representation for a many-to-many relationship?
Write the fastest query to find out how many rows exist in a table?