If a table column has is UNIQUE and has NOT NULL, is it
equivalent to a PRIMARY KEY column?

Answer Posted / dibya tara shakya

It will same but in case of primary key we can create the
master child relationship with other child table as foreign
key but in case of unique and not null we cannot.

another major difference is that Primary key constraint
applied Cluster index on that
column and unique key constraint non clustered index on
that column.

Is This Answer Correct ?    1 Yes 1 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

what is the use of triggers in Java program? I mean where do we use triggers in Java programming?

1696


How to connect the oracle server as sysdba?

633


what are bitmap indexes? How does they work?

1720


What is Library Cache in Oracle?

645


What are the different windows events activated at runtime ?

2410






What is the use of aggregate functions in oracle?

581


How to start your 10g xe server?

597


What are the uses of a database trigger?

521


Name the three major set of files on disk that compose a database in Oracle?

635


How to pass a parameter to a cursor in oracle?

597


How do I recompile a procedure in oracle?

527


Explain the use of consistent option in exp command.

554


How to turn on or off recycle bin for the instance?

611


What is blob datatype?

571


What are operators in oracle?

532