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

Explain the use of constraints in functional model, Explain the use of cons...

Explain the use of constraints in functional model with suitable example. A constraint shows relationship between two objects at same time, or   among various values of the sam

What is a relationship called when it is maintained entities, What is a rel...

What is a relationship called when it is maintained between two entities? A relationship is called Binary relationship when it is maintained between two entities.

Differentiate between a global and a local temporary table, Differentiate b...

Differentiate between a Global and a Local temporary table? - A local temporary table exists only for the duration of a connection or if defined inside a compound statement, fo

Sql iis setup and admin - maybe tfs, I want a good Microsoft Admin experien...

I want a good Microsoft Admin experienced in IIS and SQL Server. They require being able to set it up and administer from then onwards. Experience in Team Foundation Server a

ERD, A student entity type has the following attributes,name..

A student entity type has the following attributes,name..

Explain the systems development life cycle, Explain the systems development...

Explain the systems development life cycle. This is the traditional method to develop, maintain, and replace information systems that contains the project identification and se

Insertion anomaly-data redundancy, Insertion Anomaly: Inability to show ce...

Insertion Anomaly: Inability to show certain information-The primary key of the over relation be (enrolment number, Cno). Any new tuple to be inserted in the relation should have

What is a view, What is a view? A view is a logical view on one or more...

What is a view? A view is a logical view on one or more tables.  A view on one or more tables i.e., the data from a view is not actually physically kept instead being derived f

Describe query evaluation engine, Describe Query evaluation engine? Que...

Describe Query evaluation engine? Query Evaluation engine: Vehicle executes low-level instructions obtained through the DML compiler. The Storage Manager Components gives 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