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

Query optimization, what is meant semantic query optimization? how does it ...

what is meant semantic query optimization? how does it differ from other query optimization techniques?

What is e-r model, What is E-R model? This data model is based on real ...

What is E-R model? This data model is based on real world that having of basic objects called entities and of relationship between these objects. Entities are explained in a da

Define the wait for graph, Define the Wait for graph Ans: The wait-for-...

Define the Wait for graph Ans: The wait-for-graph is a directed graph and consist of nodes and directed arcs; the nodes of the graph are active transactions. An arc of the grap

Fragmentation, let us consider a table having 2200 records and the fixed si...

let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation

What is identity, What is Identity? Identity (or AutoNumber) is a colum...

What is Identity? Identity (or AutoNumber) is a column that automatically produces numeric values. A start and increment value can be set, but most DBA leave these at 1. A GUID

What is trigger, What is trigger?  Triggers are statements that are exe...

What is trigger?  Triggers are statements that are executed automatically by the system as the side effect of a modification to the database.

Assignment topic, assume we have the following apllicationthat model sccer ...

assume we have the following apllicationthat model sccer team the games they play and the players inv each teamin the design we want to capture

Which data manipulation command combines the records, Which data manipulati...

Which data manipulation command combines the records from one or more tables ? JOIN data manipulation command combines the records from one or more tables.

What is mysql, What is MySQL? MySQL is a relational database management...

What is MySQL? MySQL is a relational database management system which has eleven million installations. It can be used for both Linux and Window. Managing database includes add

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