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 alternate key, What is Alternate Key Alternate Key: This is t...

What is Alternate Key Alternate Key: This is the candidate key which is not taken as the primary key of the table. They are named so because although not the primary key, the

Data dictionary, how to prepare a data dictionary for online examination sy...

how to prepare a data dictionary for online examination system for certified courses?

Sequences-data control, Sequences Sequences: Automatically produ...

Sequences Sequences: Automatically produce unique numbers Are sharable Are typically used to make a primary key value Replace application code Speed up t

Insertion anomaly-data redundancy, Insertion Anomaly: Inability to show ce...

Insertion Anomaly: Inability to show certain information-The primary key of the over relation be (enrolment number, Cno). Any new tuple to be inserted in the relation should have

What is a recursive relationship, What is a recursive relationship? Give an...

What is a recursive relationship? Give an example not used in the text. A recursive relationship is a relationship among an entity and itself. For example, given the entity PER

Candidate keys, Super keys of a relation can have extra attributes. Candida...

Super keys of a relation can have extra attributes. Candidate keys are minimal super key, i.e. such a key have no extraneous attribute. An attribute is known as extraneous if even

Need website hacking security test, We want have a website; we need to test...

We want have a website; we need to test the security of our website. You need to: -Try to bypass our security by simulate a website hacking -Try some hack Techniques like

What is system catalog or catalog relation, What is system catalog or catal...

What is system catalog or catalog relation? How is better known as? A RDBMS maintains a explanation of all the data that it contains, information about every relation and index

Abap/4 statements to access internal tables without header, What should be ...

What should be declared explicitly in the corresponding ABAP/4 Statements to access internal tables without header lines & why? Work Area. This is needed as the Work Area is

Define the concept of design documentation, Design Documentation  The ...

Design Documentation  The Design Document shall be an extension of Requirements Analysis Design. "The Design Document will comprise a revised and much more detailed descrip

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