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

What is an object id, What is an object ID? Each class-derived table ha...

What is an object ID? Each class-derived table has an ID for primary key, one or more object IDs form primary key for association derived tables. An object ID is equivalent dat

Distributed database management system, Question (a) Differentiate betw...

Question (a) Differentiate between the following terms: (i) Distributed Database v/s Distributed Database management System (ii) Homogeneous Distributed Database v/s Hete

Explain the two constraints check and foreign key in sql, Explain the two c...

Explain the two constraints, check and foreign key in SQL along with an example for each. Give the syntax. CHECK constraint - CHECK constraint specifies an expression which

Data base model, why are older data base model are being replaced by new da...

why are older data base model are being replaced by new data model

Define deadlock detection, Define Deadlock detection If a system does ...

Define Deadlock detection If a system does not employ a few protocols that make sure deadlock freedom, after that a detection and recovery scheme should be used. An algorithm

Design and build a data mart, You are required to design and build a data m...

You are required to design and build a data mart/data warehouse using Oracle. A national bank allocates funding every year for its local branches to provide temporary staff cove

Describe object relational model, Describe Object Relational model ? O...

Describe Object Relational model ? Object Relational Model - This model combines the characteristics of both relational model and object oriented model. It extends the tradit

Nested relational model, what is Nested relational model? Explain with exam...

what is Nested relational model? Explain with examples.

How is concurrency identified, How is concurrency identified? Concurren...

How is concurrency identified? Concurrency in objects can be identified by the way they alter their state. Current objects can change their state independently. Aggregation imp

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