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

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

Importance of file organisation in database, Importance Of File Organisatio...

Importance Of File Organisation In Database To execute a database efficiently, there are various design tradeoffs needed. One of the most vital ones is the file Organisation. F

Explain forms based and graphical interface, Explain forms based and graphi...

Explain forms based and graphical interface? Forms based and graphical interface: graphical user interface (GUI) is a kind of user interface which permits people to interact

Define value set, Define value set? Value set: It is a set of values. Y...

Define value set? Value set: It is a set of values. You do not always need a user to enter junk free text within all the fields. Therefore, Oracle Apps uses value set to valida

What is difference between truncate and delete, What is difference between ...

What is difference between TRUNCATE and DELETE? - Truncate can't be rolled back whereas Delete can be. - Truncate keeps the lock on table whereas Delete keeps the lock on ea

List the requirements needed to design a trigger, List the requirements nee...

List the requirements needed to design a trigger. The requirements are:- Specifying when a trigger is to be implemented. State the actions to be taken when the trigger im

Explain about database system structure, Explain about database system stru...

Explain about database system structure? Storage manager Authorization and integrity manager Transaction manager File manager Buffer manager Storage manager

Explain interblock gap, Explain Interblock gap? Interblock Gap - A trac...

Explain Interblock gap? Interblock Gap - A track of a disk is separated into equal-sized disk blocks. Blocks are separated through fixed-size gaps, called as interblock gaps th

State about the activity diagram, State about the Activity Diagram Act...

State about the Activity Diagram Activity diagrams show flow from one activity to other. It is an ongoing non atomic execution within a state machine. Activity finally results

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