Explain weak and strong entity type, Database Management System

Assignment Help:

Explain weak and strong entity type ?

Weak and Strong entity type: An entity set which does not have a primary key is referred to as a weak entity set. The existence of a weak entity set depends on the existence of a strong entity set; it must associate to the strong set via a on-to-many relationship set. A discriminator of a weak entity set is the set of attributes that distinguishes between all the entities of a weak entity set. The primary key of a weak entity set is formed by the primary key of the strong entity set on that the weak entity set is existence depends, plus the weak entity set's discriminator.


Related Discussions:- Explain weak and strong entity type

What do you mean by correlated subquery, What do you mean by Correlated sub...

What do you mean by Correlated subquery? Subqueries, or nested queries, are used to bring back a set of rows to be used by the parent query. Depending on how the subquery is writ

Attributes and tuple, Before we talk about the relational model in more det...

Before we talk about the relational model in more detail, let us first define some very basic terms used in this model. Tuple Every row in a table shows a record and is cal

Student, explain exhausitively the problems associated with er diagrams wit...

explain exhausitively the problems associated with er diagrams with ellustrations

Describe the capabilities offered via mysql client apis, Describe the capab...

Describe the capabilities offered via MySQL client APIs? . • Checking for errors. . • Connecting to the MySQL server, selecting a database, disconnecting from the server

Student database, tell me the functionality,advantages and disadvantages of...

tell me the functionality,advantages and disadvantages of student database

Define the terms - physical schema and logical schema, Define the terms  1)...

Define the terms  1) physical schema 2) logical schema.  Physical schema:  The physical schema explains the database design at the physical level, which  is  the  lowest  lev

What is recovery?, What Is Recovery?  During the life of a transaction, ...

What Is Recovery?  During the life of a transaction, i.e., a after the start of a transaction but before the transaction commits, various changes may be made in a database state

Describe the algorithm for updating indices, Describe the algorithm for upd...

Describe the algorithm for updating indices for a single level index when a record is    (i) Inserted  (ii)  deleted What will be the modification if there are multilevel in

Distributed and client server databases, Distributed And Client Server Data...

Distributed And Client Server Databases Introduction This unit tells the distributed database systems which are primarily relational and one important execution model: the

What is database files , The database files accept the actual data and ...

The database files accept the actual data and are typically the biggest in size. Depending on their shape, the tables for all the user operation can go in one database file-but

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