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

Linear commit protocol, With the linear commit protocol, sites are connecte...

With the linear commit protocol, sites are connected in a chain, and the subtransaction at the left-hand end of the chain initiates the protocol. Propose a crash recovery protocol

When are they useful justify with an example, When are they useful? Justify...

When are they useful? Justify with an example. The temporary tables are commonly used to support specialized rollups or exact application processing needs. Unlike a permanent t

Objectives of data management, The traffic data mgmt. systems infrastructur...

The traffic data mgmt. systems infrastructure plan describes the software, hardware, data network, and other elements that will support the TDMS. The infrastructure plan is based o

List the types of authorization, List the types of authorization. A) R...

List the types of authorization. A) Read authorization B) Write authorization C) Update authorization D) Drop authorization

Describe the benefits of OOD techniques, Describe the benefits of OOD techn...

Describe the benefits of OOD techniques OOD techniques are very useful for development of large and complex systems. It has been noted that large projects that are developed u

The locking protocol, The Locking Protocol: To manage concurrency related ...

The Locking Protocol: To manage concurrency related problems we use locking. A lock is mainly a variable that is associated with a data item in the database. A lock can be located

What is meant by physical blocks, What is meant by Physical blocks? The...

What is meant by Physical blocks? The input and output operations are completed in block units. The blocks residing on the disk are referred to as physical blocks.

Data model in DBMS, how many types of data model in DBMS? explain data abst...

how many types of data model in DBMS? explain data abstraction with its different level

Reasons for the growing popularity of data mining, Question: Data Minin...

Question: Data Mining is the process of extracting knowledge hidden from large volumes of raw data. (a) Using a suitable example, illustrate how Data Mining can be useful t

Command line interfaces, Command Line Interfaces: These are interactive int...

Command Line Interfaces: These are interactive interfaces, character-based that let you use the complete power and functionality of the DBMS query language directly. They permit yo

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