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

Windows 8 Administrative Tools, Which two tools are used to administer user...

Which two tools are used to administer users for Active Directory?

Explain the exists and unique functions of sql, Explain the EXISTS and UNIQ...

Explain the EXISTS and UNIQUE functions of SQL. Give an example for each? EXISTS: The EXISTS function takes one parameter that is a SQL statement. If any records exist which

Constraints violation during insertion, If the insertion violates one or mo...

If the insertion violates one or more constraints, then two alternatives are available: Default option: - Insertion can be discarded and the reason of refusal can also be ex

Increased overheads on update-data replication, Increased overheads on upda...

Increased overheads on update : On the drawbacks side, it will need the system to ensure that all replicas of a relation are consistent. This shows that all the replicas of the rel

Create a company database, Company Database: a-)Here is the ER Model ...

Company Database: a-)Here is the ER Model b-)Here is the Relational Model:     IMPORTANT NOTICE FOR SOLUTION TYPE: ***THIS ASSIGNMENT WILL BE SOLVED BY THE

Define multivalued dependency, Define multivalued dependency.  What do unde...

Define multivalued dependency.  What do understand by trivial multivalued dependency?  Ans: A multivalued dependency is a full constraint among two sets of attributes in a rela

Fragmentation, let us consider a table having 2200 records and the fixed si...

let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation

What is enterprise resource planning, What is Enterprise Resource Planning ...

What is Enterprise Resource Planning (ERP), and what kind of a database is used in an ERP application? Enterprise Resource Planning (ERP) is an information system used in manuf

Cartisian product, Explain the cartesian product in Database Management Sys...

Explain the cartesian product in Database Management System

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