patilpravin_1981

 Profile Answers by patilpravin_1981 

• Jan 29th, 2008

 

A person can have same name in database therfore it is difficult to identify the records thats why DBMS provide data integrity to enter valid data & unique data enter into database. which is use to avoid data redudancey in database.

artbria

 Profile Answers by artbria 

• Aug 25th, 2008

 

A table is said to be redundant (that is data is repeated) if it is in a denormalized format. For ex, we have a table, which displays item, item no, item cost etc. which is denormalized. To avoid redundancy, we normalize it and add some more fields like sub-item, sub item no, sub item cost etc.

Now, if we write a query to retrive data from this normalized table(which dont have redundant data), it will take take a long time for the query to get executed as the no of fields increase.

hence, redundancy of data is benifical, that is query processing time will be minimal.