Golgappa.net | Golgappa.org | BagIndia.net | BodyIndia.Com | CabIndia.net | CarsBikes.net | CarsBikes.org | CashIndia.net | ConsumerIndia.net | CookingIndia.net | DataIndia.net | DealIndia.net | EmailIndia.net | FirstTablet.com | FirstTourist.com | ForsaleIndia.net | IndiaBody.Com | IndiaCab.net | IndiaCash.net | IndiaModel.net | KidForum.net | OfficeIndia.net | PaysIndia.com | RestaurantIndia.net | RestaurantsIndia.net | SaleForum.net | SellForum.net | SoldIndia.com | StarIndia.net | TomatoCab.com | TomatoCabs.com | TownIndia.com
Interested to Buy Any Domain ? << Click Here >> for more details...

What is the difference between primary key & unique index ?

Answer Posted / palash ghosh

1)Primary key creates an implicit culstered index on a
table, unique key does not create any implicit index.
2)Columns defined as primary key does not allow null values,
where as columns defined as unique can allow null values.
3)A table can have just one primary key (can be a composite
key) where as there can be multiple unique columns (keys).
4)Primary key is a unique key with the above mentioned
features.

Is This Answer Correct ?    9 Yes 1 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Can we delete records from view?

974


How do you simulate the explain of an embedded sql statement in spufi/qmf?

1094


What is a plan and package in db2?

1110


What is table space in db2?

1026


How to restart a DB2 program?

1912


How to fetch the last row from the table in SQL (db2)?

1660


Explain how can you do the explain of a dynamic sql statement?

1130


On which levels locks can be applied?

1145


What is the difference between cursor stability and repeatable read isolation levels?

1186


How to get the ddl of a table in db2?

1134


What is reorg and runstats in db2?

1226


How will you return the number of records in table?

945


What is collection in db2 bind?

1022


Highlight all the advantages that are attached to a package.

1124


Mention the various locks that are available in db2.

1050