What is index, Database Management System

Assignment Help:

What is Index?

An index is a physical structure having pointers to the data. Indices are created in an existing table to locate rows more quickly and efficiently. It is possible to create an index on one or more columns of a table, and each index is given a name. The users cannot see the indexes; they are just used to speed up queries. Effective indexes are one of the best ways to improve performance in a database application. A table scan occurs when there is no index available to help a query. In a table scan SQL Server examines every row in the table to satisfy the query results. Table scans are sometimes unavoidable, but on large tables, scans have a terrific impact on performance.

 


Related Discussions:- What is index

Atomicity-transaction , Atomicity: It describes a transaction to be a one ...

Atomicity: It describes a transaction to be a one unit of processing. We can also say either a transaction will be finished completely or not at all. In the transaction example 1

Process of adjustment of inheritance, Process of Adjustment of inheritance ...

Process of Adjustment of inheritance During object design, inheritance is readjusted by rearranging classes and operations, and abstracting common behaviour.

In an e-r diagram an entity set is represent by, In an E-R diagram an entit...

In an E-R diagram an entity set is represent by? In an E-R digram entity set is represted by rectangle.

Explain degree of relation, Explain degree of relation? Degree of a Re...

Explain degree of relation? Degree of a Relation - The degree or arity of a relation is the number of attributes n of its relation schema.

Data warehouse, XYZ is a large chain of home entertainment rental over 100 ...

XYZ is a large chain of home entertainment rental over 100 stores distributed over all states in Australia. XYZ lends entertainment products such as movies, TV shows and games on v

C PROBLEMS, how to solve the C type problems?

how to solve the C type problems?

multiple-mode locks, Multiple-mode locks : It offers two locks: exclusive ...

Multiple-mode locks : It offers two locks: exclusive locks and shared locks. But why do we require these two locks? There are a lot of transactions in the database system that neve

Write the sql queries using data manipulation language, Problem 1. Writ...

Problem 1. Write the SQL queries using Data Manipulation Language (DML) statements. Insert values into student table with field names using insert command Display the

Entities, Entities Let us first be aware of the question: What are e...

Entities Let us first be aware of the question: What are entities? An entity is an object of concern used to show the things in the actual world, e.g., table, car, bo

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