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

What is the use of unique function, What is the use of unique function? ...

What is the use of unique function? UNIQUE function: If UNIQUE is specified then only unique values are used to computed the mean.

Illustrate how customer relationship is promoted, FitAll Ltd is a company t...

FitAll Ltd is a company that manufactures clothes. Its processes are manual and there are stand-alone Information Systems that aid to manage them. The Information Systems were purc

What is a b+-tree index, What is a B+-Tree index? A B+-Tree index takes...

What is a B+-Tree index? A B+-Tree index takes the form of a balanced tree in which each path from the root of the root of the root of the tree to a leaf of the tree is of the

What is a cascading update, What is a cascading update? Referential int...

What is a cascading update? Referential integrity constraints needs that foreign key values in one table correspond to primary key values in another. If the value of the primar

Attributes and tuple, Before we talk about the relational model in more det...

Before we talk about the relational model in more detail, let us first define some very basic terms used in this model. Tuple Every row in a table shows a record and is cal

Which operator is used to compare a value to a list literals, Which operato...

Which operator is used to compare a value to a list of literals values that have been specified? BETWEEN operator is used to compare a value to a list of literals values that h

Database, . Ashutosh Dubey who is the director of Gyan Gurukul want a three...

. Ashutosh Dubey who is the director of Gyan Gurukul want a three-level schema architecture for the Gyan Gurukul Company that provide better security also design a data abstraction

What features relational dbms contribute level of integrity, A well-maintai...

A well-maintained relational DBMS has a high level of data integrity. What features of a relational DBMS contribute towards this level of integrity? Relational DBMS gives high

Er diagrams, in an organization several projects are undertaken. Each proje...

in an organization several projects are undertaken. Each project can employ one or more employees. Each employee can work on one or more projects. Each project is undertaken on the

Non-redundant cover and canonical cover, Given the following set of functio...

Given the following set of functional dependencies {cf?bg, g?d, cdg?f, b?de, d?c} defined on R(b,c,d,e,f,g) a.Find a non-redundant cover. b.Find a canonical cover.

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