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 are the benefits of prepared statements, What are the benefits of prep...

What are the benefits of prepared statements and place holders? Parameter binding operations automatically handle escaping of characters Encourage Statement reuse

Define the term domain, Define the term Domain. For each n every attrib...

Define the term Domain. For each n every attribute there is a set of permitted values known as the domain of that attribute.

Differences among the candidate keys and the primary key, Discuss the diffe...

Discuss the differences among the candidate keys and the primary key of a relation. Give instance to describe your answer? A candidate key is one that can be used as primary ke

Replicating data, Replicating Data One approach that may support effici...

Replicating Data One approach that may support efficient access to dissimilar applications as above may be to give access to every of the applications from dissimilar replicate

Why does a dbms query language is designed, Why does a DBMS query language ...

Why does a DBMS query language is designed? A DBMS query language is designed to support end users who use English-like commands. support in the development of complex applicat

Explain authorization and integrity manager, Explain Authorization and Inte...

Explain Authorization and Integrity Manager ? Authorization and Integrity Manager: Tests for the satisfaction of integrity constraints and checks the authority of users to acce

What is a value, What is a value? A data value is used for identity. Th...

What is a value? A data value is used for identity. This form of identity is used in relational systems.eg: The primary key value of a tuple recognize the tuple.

Create table to evaluating websites-reasoning, Have a look around the site,...

Have a look around the site, and at some of the sites they have featured. These are all examples of bad design, and also offer an explanation about why they fall into this category

Explain in detail about collaboration diagrams, Explain in detail about Col...

Explain in detail about Collaboration Diagrams Collaboration diagrams are interaction diagrams which emphasize structural organisation of an object that transmit and receive m

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