What is primary index, Database Management System

Assignment Help:

Primary Index

In primary index, there is a one-to-one relationship among the entries in the index table and the records in the major table. Primary index can be of two types:

Dense primary index: the number of entries in the index table is the similar as the number of entries in the major table. In other words, each and every record in the major table has an entry in the index.

Sparse or Non-Dense Primary Index:

For large tables the Dense Primary Index itself starts to grow in size. To keep the size of the index smaller, instead of pointing to each and every record in the major table, the index points to the records in the main table in a gap.

 


Related Discussions:- What is primary index

What is dml query langauge, What is DML Query Langauge? Data Manipulati...

What is DML Query Langauge? Data Manipulation Language (DML) - A data manipulation language is a language in which enables users to access or manipulate data as organized throu

Dirty reads-problems of concurrent transactions, Dirty Reads: T10 reads a ...

Dirty Reads: T10 reads a value which is updated by T9. This update has not been committed and T9 aborts. T9 T10 Value of x old value = 200

Create a view that finds the student name, Section A:  Use the following ta...

Section A:  Use the following tables to create a database called College.  Use SQL commands. Student stuid(primary) lastName firstName

Main difference between read-only and update methods, What is the main diff...

What is the main difference between read-only and update methods? A read-only method does not affect the values of a variable in an object, whereas an update method may alter t

Provide examples of different types of time and date formats, Provide Examp...

Provide Examples of different types of Time and Date formats.  It's most common store dates using a dash (-) as a colon (:)and the delimiter as the time delimiter. The given fo

Normalization, in case of functional dependencies how we get the higher nor...

in case of functional dependencies how we get the higher normal form.

Define direct file organization, Define Direct file organization? The d...

Define Direct file organization? The direct file organization is employed to enhance the performance in accessing the records than sequential file organization. In direct file

E-r diagram, Let us now make the E-R diagram for the student database as pe...

Let us now make the E-R diagram for the student database as per the explanation given in the previous section. We can also states the overall logical structure of a database usi

Describe participation constraints, Describe Participation Constraints? ...

Describe Participation Constraints? Participation Constraints - The participation constraint exacts whether the existence of an entity depends on its being related to another

Explain the shadow paging recovery technique, Explain the shadow paging rec...

Explain the shadow paging recovery technique.  Ans: Shadow paging is a method used to acquire atomic and durable transactions, and provides the capability to manipulate pages i

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