Join operation, Database Management System

Assignment Help:

The JOIN operation is applied on two relations. When we want to choose related tuples from two given relation join is used. The join operation need that both the joined relations must have at least single domain compatible attributes.

Syntax:

R1 R2 is used to join related tuples from two relations R1 and R2 into a single tuple.

is of the form:

ANDAND..............AND.

  • Degree of Relation:

Degree (R1   R2) <= Degree (R1) + Degree (R2).

  • There are three types of joins:

a)   Theta join

When every condition is of the form A θ B, A is an attribute of R1 and B is an attribute of R2 and have the similar domain, and θ is one of the comparison operators { ≤, ≥, ≠, =, <, <}.


Related Discussions:- Join operation

Distributed query and transaction processing, Distributed query and transac...

Distributed query and transaction processing a.  Construct a query around any one of the functional divisions you made in 4a such that if executed in the distributed design of 4

Sequential file organisation, Sequential File Organisation The most nec...

Sequential File Organisation The most necessary way to organise the collection of records in a file is to use sequential Organisation. Records of the file are stored in series

ERD, The entity type STUDENT has the following attributes: Student Name, Ad...

The entity type STUDENT has the following attributes: Student Name, Address, Phone, Age, Activity, and No of Years. Activity represents some campus-based student activity, and No o

Describe the iterative and incremental life cycle, Describe the iterative a...

Describe the iterative and incremental life cycle For an iterative and incremental life cycle, two criteria are process and time. The main components of showing a project devel

Domain constraints, Domain Constraints Domain constraints are primarily...

Domain Constraints Domain constraints are primarily formed for defining the logically correct values for an attribute of a relation. The relation allows attributes of a relatio

Which product produces the relation that has attributes, Which product prod...

Which product produces the relation that has attributes of R1 and R2 ? Cartesian product produce the relation which has attributes of R1 and R2

Oracle/sql, can you create a database for me in oracle/sql

can you create a database for me in oracle/sql

Data aggregation, Q.   Explain  data aggregatio n and discuss differen...

Q.   Explain  data aggregatio n and discuss different design constraints. Sol. Aggregation   One limitation of the E-R model is that it cannot express relationships amon

Explain the cartesian product, Explain the Cartesian product:  The Cart...

Explain the Cartesian product:  The Cartesian product operation does not need relations to union-compatible.  The meaning of this is that the involved relations may have dissim

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