Define partial key and primary key, Database Management System

Assignment Help:

Define Partial Key and Primary Key

A partial key, also known as discriminator, is the set of attributes which can uniquely identify weak entities that are related to similar owner entity. Primary key is a unique key but not comprise null values. An entity set can comprise at most one primary key.


Related Discussions:- Define partial key and primary key

Create an entity relationship diagram, Cyber Transit Ltd keeps up-to-date i...

Cyber Transit Ltd keeps up-to-date information on the processing and current position of each dispatched item. Dispatched items are the main concern of the Cyber Transit product tr

Cartesian product, If R1 and R2 are two relations or functions, then the re...

If R1 and R2 are two relations or functions, then the result of R3 = R1 × R2 is the combination of tuples that are in R1 and R2. The product is associative and commutative. Degr

Create records in a table - data structures, In this exercise you will crea...

In this exercise you will create ten records, each containing the following fields: student name, class:  Freshman, Sophomore, Junior or Senior, Major:  Liberal Arts or General Sci

What is called a query -execution engine, What is called a query -execution...

What is called a query -execution engine? The query implementation engine takes a query evaluation plan, implements that plan, and returns the answers to the query.

Database system design and Implementation, Consider a typical sales invoice...

Consider a typical sales invoice that would include the following information. Design a single table to hold all of the information required to store an invoice including this info

In the architecture of a database system which external leve, In the archit...

In the architecture of a database system which external level used? In the architecture of a database system view external level used.

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