What is meant by heuristic optimisation, Database Management System

Assignment Help:

What is meant by heuristic optimisation?  Discuss the main heuristics that are applied during query optimisation. 

Ans:  In heuristic optimization, heuristics are employed to reduce the cost of optimization in place of analyzing the number of different plans to make out the optimal plan. For instance, a heuristic optimizer would make use of the rule 'Perform selection operation as early as possible' without finding out whether the cost is reduced by this transformation. Heuristics approach generally assists to reduce the cost but not all the time. The major heuristics that are applied throughout query optimization are:

  • Pushes the selection and projection operations down the query tree
  • Left-deep join trees - convenient for pipelined evaluation
  • Non-left-deep join trees

Related Discussions:- What is meant by heuristic optimisation

advantages of database over file system, Q.   Why would you choose a datab...

Q.   Why would you choose a database system instead of simply storing data in operating system file? Define  at a base concept in details. Sol. Advantages of Database over Fil

Whenever the limit clause will be used, Whenever the LIMIT clause will be u...

Whenever the LIMIT clause will be used? LIMIT is used for the following kinds of problems: 1) Answering questions about first or last and largest or smallest 2) Splitting

Cartisian product, Explain the cartesian product in Database Management Sys...

Explain the cartesian product in Database Management System

Analyzing association traversal, Analyzing Association Traversal Assoc...

Analyzing Association Traversal Association Traversal shall be understood properly for the association design explanation.  Analyzing association traversal means analyzing tra

Php optimization on iis 8, Project Description: We have purchased facebo...

Project Description: We have purchased facebook style chat software which we are using with our site. It is prepared in PHP but the rest of the site is developed asp.net. Iss

What is bankers algorithm, What is banker's algorithm?  Banker's algori...

What is banker's algorithm?  Banker's algorithm is a deadlock avoidance algorithm that is applicable to a resource-allocation system with multiple instances of each resource ty

Explain the relational completeness, Explain the Relational Completeness ...

Explain the Relational Completeness Codd described the term relational completeness to consider to a language that is complete with respect to first-order predicate calculus ex

Which is another name for weak entity, Which is another name for weak entit...

Which is another name for weak entity? Child is another name of weak entity.

Explain the disadvantages of file oriented approach, Explain the disadvanta...

Explain the disadvantages of file oriented approach? In the oriented approach Applications are designed in isolation. Design of application is optimized for one application. 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