Sparse and dense indexes, Database Management System

Assignment Help:

Sparse and Dense Indexes

These indexes in principle are the similar as that of indexes used at the back of the book. The key facts of the indexes are:

  • They are arranged on the order of the index value (ascending or descending) as per the option of the creator.
  • The indexes are logically individual files (just like individual index pages of the book).
  • An index is firstly formed for fast access of information.
  • The primary index is the index on the ordering field of the data file while a secondary index is the index on any other field, therefore, more useful.

 But what are dense and sparse indexes?

 Sparse indices are the indices that do not contain all the available values of a field. An index sets the records as per the index values. A sparse index is where the size of the group is one or more, whereas in a dense index the size of the group is 1. In other words a dense index have one index entry for each value of the indexing attributes, while a sparse index also known as non-dense index have few index entires out of the available indexing attribute values. For instance, the primary index on enrolment number is sparse, whereas secondary index on student name is dense.

 

 


Related Discussions:- Sparse and dense indexes

What is object identity, What is object identity? An object retains its...

What is object identity? An object retains its identity even if some or all the values of variables or explanations of methods change overtime.

What is conceptual model, What is conceptual model ? A conceptual model...

What is conceptual model ? A conceptual model is a independent of both hardware and software.

Advantages of database systems, Problem 1. Describe the following a)...

Problem 1. Describe the following a) Advantages of Database Systems b) Functions of a DBMS Explanation of part (a) and (b) 2. Explain the following concepts w

Relational database, Consider the following relational database: STUDENT (n...

Consider the following relational database: STUDENT (name, student#, class, major) COURSE (course name, course#, credit hours, department) SECTION (section identifier, course#, sem

Descrine an data dictionary, Describe an data dictionary? A data dictio...

Describe an data dictionary? A data dictionary is a data structure which keeps meta data about the structure of the database ie. the schema of the database.

OLAP CUBES, 1) Define a job scheduling strategy that will meet business req...

1) 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 pict

State the definition of association, State the definition of association ...

State the definition of association An association is a structural relationship which specifies that objects of one thing are connected with objects of another. In UML, asso

Creating a view-data control, Creating a view: A query can be embed...

Creating a view: A query can be embedded within the CREATE VIEW STATEMENT A query can have complex select statements containing join, groups and sub- queries A quer

Sources of utilities for a dbms, There are three main sources of utilities ...

There are three main sources of utilities and applications for a DBMS: a. Vendor applications and utilities are given for working with or maintaining the database, and generally

Create data base table apply key and functions, CREATE YOUR DATABASE TABLES...

CREATE YOUR DATABASE TABLES Your database project must have a minimum of four tables. Include the SQL scripts used to create the tables in your documentation. Explain the tables

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