What are the general transformation rules, Database Management System

Assignment Help:

What are the General Transformation Rules for Relational operations? 

Ans: The transformation rules transform one relational algebra expression to AN

EQUIVALENT ONE 

1. Employed by the query optimizer to optimize query tree 

2. Any type of rule, if applied, ensures that the resultant tree is equivalent → resulting execution plan is equivalent 

 General Transformation Rules is as follow:

1. Commutativity of s: The s operation is commutative: 

  • sc1 (sc2(R)) = sc2 (sc1(R))
  • More selective selections first

Related Discussions:- What are the general transformation rules

Define database management system, Define database management system? D...

Define database management system? Database management system (DBMS) is a set of interrelated data and a combination of programs to access those data.

Update anomaly-data redundancy, Update Anomaly : This anomaly is occurred d...

Update Anomaly : This anomaly is occurred due to data redundancy. Redundant information makes updates more complex since, for example, varying the name of the instructor of MCS-014

Develop motel point of sale software, Project Description: I need a poin...

Project Description: I need a point of sale for motels. It needs to run on windows and requires being network able so that we can have more than one computer using it at once.

ER diagram, #question. acompani datdbase needs to store information about e...

#question. acompani datdbase needs to store information about employees (identified by a social security number,with salary and phone as attributes) and departments (identified by

School portal design and development, Project Description: This is going...

Project Description: This is going to be a School portal to handle each activities in school such as, School fees payment, online registration and every other payment, course re

Explain the term- periodic recomputation, Explain the term- Periodic recomp...

Explain the term- Periodic recomputation Periodic recomputation:  Base values are often updated in bunches. Sometimes, it is possible to just recompute all derived attributes p

Load - unload utilities, These permit the user to unload a database or part...

These permit the user to unload a database or parts of a database and reload the data on the similar machine, or on another machine in a dissimilar location. This can be useful in

Entity integrity constraint - relational constraints, It defines that no pr...

It defines that no primary key value can be null. This is as the primary key is used to recognize individual tuple in the relation. So we will not be able to recognize the records

Describe the term- state diagram, Describe the term- State Diagram Sta...

Describe the term- State Diagram State Diagram: An object could receive a sequence of the input instructions. The state of the object can differ depending upon sequence of in

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