Differentiate between a unique key and a primary key, Database Management System

Assignment Help:

Differentiate between a unique key and a primary key.

- By default, clustered index on column are created by primary key while nonclustered index are created by unique key.

- Primary key doesn't allow NULLs however unique key allows one NULL.

 


Related Discussions:- Differentiate between a unique key and a primary key

Inheritance, what is relationship inheritance and attribute inheritance

what is relationship inheritance and attribute inheritance

Consider relational schema and construct algebra query, Consider the follow...

Consider the following relational schema: PERSON (SS#, NAME, ADDRESS) CAR (REGISTRATION_NUMBER, YEAR, MODEL) ACCIDENT (DATE, DRIVER, CAR_REG_NO) OWNS (SS#, LICENSE) Constru

Logical operators-logical operators, Logical Operators Rules of Preced...

Logical Operators Rules of Precedence: Order evaluated Operator 1 All comparison operators 2

Physical location of record is determined by which formula, The physical lo...

The physical location of a record is determined by which mathematical formula that transforms a file key into a record location? The physical location of a record is determined

What is a data dictionary, What is a data dictionary?  A data dictionar...

What is a data dictionary?  A data dictionary is a data structure which keeps Meta data about the structure of the database i.e.  the schema of the database.

Relational database integrity, A database is a set of data. But, is the dat...

A database is a set of data. But, is the data kept in a database trustworthy? To answer that query we must first answer the question. What is integrity? Integrity simply means t

Define access time, Define access time. Access time is the time from wh...

Define access time. Access time is the time from when a read or write request is issued to when data transfer starts.

What is rdbms terminology for a row, What is RDBMS terminology for a row? ...

What is RDBMS terminology for a row? A tuple is a RDBMS terminology for a row

Explain what is aggregation, Explain what is Aggregation? Aggregation:...

Explain what is Aggregation? Aggregation: Aggregation is an significant concept in database design whereas composite objects could be modelled during the design of database a

What is index, What is Index? An index is a physical structure having p...

What is Index? An index is a physical structure having pointers to the data. Indices are created in an existing table to locate rows more quickly and efficiently. It is possibl

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd