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

Memory components of sga, Problem 1. Describe the Oracle Architecture w...

Problem 1. Describe the Oracle Architecture with a neat labeled diagram, Also explain the individual components of the Architecture. 2. Write about the following Oracle 9i o

#, How to use Oracle

How to use Oracle

Explain a data dictionary, What is a data dictionary? Data Dictionary ...

What is a data dictionary? Data Dictionary is a main source of data in a data management system.  Its major function is to carry the creation and management of data definition

Explain the concept of modeling with objects, Explain the concept of Modeli...

Explain the concept of Modeling With Objects A model is a conceptual representation of a specification, design or system from a particular point of view. A modelling language

Logical operators-logical operators, Logical Operators Rules of Preced...

Logical Operators Rules of Precedence: Order evaluated Operator 1 All comparison operators 2

Read-set(t) and timestamps-optimistic concurrency contents, read-set(T) : E...

read-set(T) : Each data items that are read by a transaction T Timestamps : for all transaction T, the start-time and the end time are reserved for all the three phases.

Define the attribute inheritance, Define the Attribute Inheritance The ...

Define the Attribute Inheritance The attributes of a higher level entity set are inherited through a lower level entity set made by specialization-generalization hierarchy. Nam

What are the two types of errors, What are the two types of errors? The...

What are the two types of errors? The two types of errors are: a) Logical error b) System error

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