Sparse and dense indexes, Database Management System

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.

 

 

Posted Date: 3/8/2013 6:09:55 AM | Location : United States







Related Discussions:- Sparse and dense indexes, Assignment Help, Ask Question on Sparse and dense indexes, Get Answer, Expert's Help, Sparse and dense indexes Discussions

Write discussion on Sparse and dense indexes
Your posts are moderated
Related Questions
Haw does it work one database application

Explain the term High level DML? High level DML A high-level or non-procedural DML permit the user to specify what data is needed without specifying how it is to be acquired.

To do the division operation R1 ÷ R2, R2 should be a correct subset of R1. In the following example R1 have attributes A and B and R2 have only attribute B so R2 is a correct subse

What are stored-procedures? And what are the advantages of using them? Stored procedures are database objects that perform a user defined operation. A stored procedure can have

For your chosen project, you need to identify the current problem that you wish your project to solve.  Produce a Problem Statement.  The Problem Statement should explain the purpo

What is Management System? A management system is a set of rules and process which help us to create organize and manipulate the database. It also helps us to add, change delet

Express types of information available in MySQL? Information as regards the result of queries:  This includes number of records affected by any SELECT or UPDATE or DELETE st

Q.   Explain  data aggregatio n and discuss different design constraints. Sol. Aggregation   One limitation of the E-R model is that it cannot express relationships amon

Which data manipulation command combines the records from one or more tables ? JOIN data manipulation command combines the records from one or more tables.

Explain the Exec statement in SQL Ans: Exec statement has the structure    EXEC SQL END-EXEC   Embeded SQl statements are of a form identical to non embedded SQL statem