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

Explain odbc, Explain ODBC? ODBC - Open DataBase Connectivity (ODBC) e...

Explain ODBC? ODBC - Open DataBase Connectivity (ODBC) enable the integration of SQL along with a general-reasons programming language.

Define functional and multivalued dependencies, Define functional and multi...

Define functional and multivalued dependencies.       Ans:  A functional dependency is a assets of the semantics of the attributes in a relation. The semantics point out how at

Explain the concept of qbe, Explain the concept of QBE? Query-by-exampl...

Explain the concept of QBE? Query-by-example represents a visual/graphical approach for accessing information in a database by the use of query templates called as skeleton tab

Draw an er diagram with primary key for a farm, Draw an ER diagram that rep...

Draw an ER diagram that represents the information described below. Show all entity sets, relationship sets, primary keys, and the mapping cardinality of the relationship sets.

Differance between join and outer join, Differentiate between join and oute...

Differentiate between join and outer join? Outer joins return all rows from at least one of the tables or views mentioned within the FROM clause, as long as those rows get toge

What is the use of group by clause, What is the use of group by clause?  ...

What is the use of group by clause?  Group  by  clause  is  used to apply  aggregate  functions  to a  set  of  tuples. The attributes given in the group by clause are used to

What is a primary index, What is a primary index? A primary index is an...

What is a primary index? A primary index is an index whose search key also explains the sequential order of the file.

Define the concept of aggregation, Define the concept of aggregation.  Give...

Define the concept of aggregation.  Give two examples where this concept is useful. Ans: Aggregation transforms a relationship among the objects into a higher-level object. A

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