Define outer union operation of the relational algebra, Database Management System

Assignment Help:

Define outer union operation of the relational algebra. Compute the outer union for the relations R and S given below.

932_outer union.png


Outer Join - If there are any values in one table which do not have corresponding value(s) within the other, in an equi-join that will not be chosen. Such rows could be forcefully selected through using the outer join. The corresponding columns for in which row will have NULLs. There are actually three forms of the outer-join operation: left outer join ( X), right outer join (X ) and full outer join ( X ).

1770_outer union 1.png


Related Discussions:- Define outer union operation of the relational algebra

Large Project, Can you help me with the following: Drop statements for all...

Can you help me with the following: Drop statements for all objects in the lab project. Create statements for all objects of the lab project Create indexes for foreign keys Cre

Security-drawbacks of data distribution, Security: In a centralised system...

Security: In a centralised system, access to the data can be simply controlled. Though, in a distributed DBMS not only does access to replicated data have to be controlled in many

Database, why are older data models are being replaced by new data models

why are older data models are being replaced by new data models

Compare wait-die deadlock prevention with wait-wound scheme, Compare wait-d...

Compare wait-die deadlock prevention scheme with wait-wound scheme   Ans:  Wait-Die Scheme  a) Based upon a nonpreemptive technique.  b) If Pi requests a resource present

Explain the difference between drop and delete, Explain the Difference betw...

Explain the Difference between DROP and DELETE DELETE deletes one or more than one tuples of a particular relation from the database. DROP is employed to remove a table from th

Write short notes on transaction state, Write short notes on transaction st...

Write short notes on transaction state? A transaction may not always complete its implementation successfully such a transaction is termed aborted A transaction must be in o

Briefly describe the different kinds of users of a dbms, Briefly describe t...

Briefly describe the different kinds of users of a DBMS.  Ans: Different sorts of DBMS users are: (a)  Software Engineers: These are the people accountable for developing ap

Function module and a normal abap/4 subroutine, What is the difference betw...

What is the difference between the function module and a normal ABAP/4 subroutine? In contrast to normal subroutines function modules have uniquely exact interface.  Declaring da

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