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

Unit database integrity, Relations create the database. They must satisfy v...

Relations create the database. They must satisfy various properties, like no duplicate tuples, no ordering of tuples, and atomic attributes, etc. Relations that satisfy these basic

Types of online analytical processing tools, Describe the various types of ...

Describe the various types of Online Analytical Processing (OLAP) tools and briefly discuss how the support common analytical operations.

Dataware house, ) Define a job scheduling strategy that will meet business ...

) Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a picto

C PROBLEMS, how to solve the C type problems?

how to solve the C type problems?

ER Diagram, A database will be made to store information about patients in ...

A database will be made to store information about patients in a hospital. On arrival, each patient’s personal details (name, address, and telephone number) are recorded where poss

Relational algebra and calculus, Q.  What is relational algebra and calcul...

Q.  What is relational algebra and calculus? Explain the relational algebra operators :- Selection and predicate, set operation, joins and division. Sol. Relational Algebra

Execute sql queries, Consider the relations described below: PHYSICIAN (re...

Consider the relations described below: PHYSICIAN (regno, name, telno, city) PATIENT (pname, street, city) VISIT (pname, regno, date_of_visit, fee) Where the regno and pname ide

What are the disadvantages of relational data, What are the disadvantages o...

What are the disadvantages of relational data ? Disadvantages • Performance - If the number of tables among that relationships to be established are large and the tables t

Physical records, Physical Records These are the records that are store...

Physical Records These are the records that are stored in the secondary storage devices. For the database relation, physical records are the group of fields kept in adjacent me

Explain cursors in sql, Explain cursors in SQL? Cursors in SQL - An o...

Explain cursors in SQL? Cursors in SQL - An object used to store the output of a query for row-through-row processing through the application programs. Cursors are constructs

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