What is the difference between Primary key and
unique index?

Answer Posted / sunny kalra

Primary key: a relational database constraint. Primary key consists of one or more
columns that uniquely identify a row in the table. For a normalized relation, there
is one designated primary key.

Unique index: a physical object that stores only unique values. There can be one
or more unique indexes on a table.

Is This Answer Correct ?    0 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

what is db2 restart?

1691


What is nvl in db2?

626


List out the buffer pools in db2

628


What is bind plan?

610


What is the difference between dbm cfg and db cfg file in db2 ?

1005






How is the value function used?

600


What does runstats do in db2?

607


What is the use of runstats in db2?

577


What are the bind parameters ibm db2?

623


What is the role of the data page in the db2 database?

587


What is a db2 cursor?

624


Following a db2 update statement, what is the quickest way to compute the total number of updated rows?

624


What is the use of db2 optimizer?

611


Why do we use cursor?

599


What do you mean by commit and rollback?

592