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

Max. no. of structures in a table or structure, What is the max. no. Of str...

What is the max. no. Of structures that can be included in a table or structure. Nine.

Describe integrity constraints, Describe integrity constraints? Integr...

Describe integrity constraints? Integrity Constraints - A database is just as excellent as the information stored in it, and a DBMS must therefore help avoid the entry of inc

Ways to suggest the dba, a)  Suppose we updated the catalog tables in real ...

a)  Suppose we updated the catalog tables in real time, that is, after every update, insert, or delete SQL statement were executed-rather than only running RUNSTATS once every few

Data mining, 1.Why we need data mining? Give an example to illustrate your ...

1.Why we need data mining? Give an example to illustrate your answer. 2. Why data mining is considered as "misleading name"? 3. Distinguish the difference between database an

What is outer join, What is Outer join?  They can be employed while we ...

What is Outer join?  They can be employed while we want to keep all the tuples in R, or all those in S or all those in both relations in the result of the JOIN in spite of of w

Explain hashing techniques, Explain Hashing techniques The hashing tech...

Explain Hashing techniques The hashing techniques can be categorized as: Static Hashing Techniques - In this method, the data can be viewed a collection of buckets, along with

Illustrate the deployment diagram, Illustrate the Deployment Diagram A...

Illustrate the Deployment Diagram A deployment diagram shows all nodes on network, their processor execution and interconnections. In a dynamic model, this is used to represen

Define a relation schema, A Relation Schema represented by R(A1, A2, .....

A Relation Schema represented by R(A1, A2, ..., An) is made up of the relation name the list of attributes and R Ai that it contains. A relation is described as a set of tuples

Consistency-transaction , Consistency: This property makes sure that a com...

Consistency: This property makes sure that a complete transaction implementation takes a database from one consistent state to another consistent state. If the transaction fails e

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.

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