Define views in relational algebra, Database Management System

Assignment Help:

Views in relational algebra: 

 1. Basic expression contains either 

a) A relation in the database.

b) A constant relation.

2.  General expressions are madde out of smaller sub expressions using 

a) σp(E1) select (p a predicate) 

b) ∏s(E1) project (s a list of attributes) 

c) Px(E1)rename (x a relation name) 

d) E1∪E2 union

e) E1- E2 set difference 

f) E1x x E2 cartesian product


Related Discussions:- Define views in relational algebra

Data handling and research methods, Data Handling and Research Methods: ...

Data Handling and Research Methods: The dataset encompassing 130 participants contains several variables measuring detrimental health related behaviours referring to the use o

Explain the reason for keeping legacy system, In order to keep pace with co...

In order to keep pace with competitors, Space Ltd has decided to implement an ERP system in order to replace its old legacy and manual systems. Management does not have much knowle

Give an expression within sql for queries, Consider the following relations...

Consider the following relations:  S (S#, SNAME, STATUS, CITY)  SP (S#, P#, QTY)  P (P#, PNAME, COLOR, WEIGHT, CITY) Give an expression within SQL for each of queries b

Derived horizontal fragmentation, Derived horizontal fragmentation: Some ap...

Derived horizontal fragmentation: Some applications may include a join of two or more relations. If the relations are stored at dissimilar locations, there may be a major overhead

Central database schema, Consider an information system designed for an onl...

Consider an information system designed for an online company which provides IT products and services. These include desktops, laptops, networking products, IT books, parts, and te

Explain the rules for creating a labelled precedence graph, Explain the rul...

Explain the rules for creating a labelled precedence graph for testing view serializability.            Ans: A schedule S is view serializable if it is view equivalent to a ser

Development of an ER diagram and database implementation, i want answers th...

i want answers this assignment now if yiu can maket for me now ?

Modular growth, Modular growth: In distributed environments, it is simple t...

Modular growth: In distributed environments, it is simple to expand. Latest sites can be added to the network without affecting the operations of other sites, as they are somewhat

Key, Q.   Explain the terms key constraints participation constraints and m...

Q.   Explain the terms key constraints participation constraints and mapping caradinalities in ER model.  Participation Constraints :   The participation of an entity set E i

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