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

Unix System Administration, What Command You Use What Day of the week were ...

What Command You Use What Day of the week were you born

What are called index-sequential files, What are called index-sequential fi...

What are called index-sequential files? The files that are ordered sequentially with a primary index on the search key are known as index-sequential files

Describe logical data independence, Describe logical data independence ? ...

Describe logical data independence ? Logical Data Independence - It is the capacity to modify the conceptual schema without having to change external schemas or application p

Computing the closure of a set of functional dependency, What is meant by c...

What is meant by computing the closure of a set of functional dependency? The closure of F denoted by F + is the set of functional dependencies logically implied by F.

Set difference, Set Difference If R1 and R2 are two union compatible re...

Set Difference If R1 and R2 are two union compatible relations or relations then result of R3 =R1- R2 is the relation that have only those tuples that are in R1 but not in R2.

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

Explain about database system structure, Explain about database system stru...

Explain about database system structure? Storage manager Authorization and integrity manager Transaction manager File manager Buffer manager Storage manager

Database for Managers, I have to create a database about anything of my cho...

I have to create a database about anything of my choice. It has to contain 4 queries, and 4 forms. It can be anything as simple as a shoe inventory with numbers - is this a service

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