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

Data fragmentation-use of partial data by applications, Use of partial data...

Use of partial data by applications : In common, applications work with views rather than whole relations. Thus, it may be more appropriate to work with subsets of relations rather

What are the various symbols used to draw an e-r diagram, What are the vari...

What are the various symbols used to draw an E-R diagram? Explain with the help of an example how weak entity sets are represented in an E-R diagram. Various symbols used to d

Write short notes on domain relational calculus, Write short notes on domai...

Write short notes on domain relational calculus   The domain relational calculus uses domain variables that take on values from an attribute domain rather than values for whole

Define union compatibility, Define union compatibility? Explain why INTERSE...

Define union compatibility? Explain why INTERSECTION of two relations cannot be performed if they are not union compatible? Two relations R(A1, A2,-------, An) and S(B1, B2,--

ERD DIAGRAM, Law Associates is a large legal practice based in Sydney. You...

Law Associates is a large legal practice based in Sydney. You have been asked to design a data model for the practice based upon the following specification: The practice employs

Mysql, he SQL query that will return the order number, quantity ordered, pr...

he SQL query that will return the order number, quantity ordered, price each and total cost of an order (quantity * price each) from the order details table. Label the calculated c

What is a database graph, What is a database graph? The partial orderin...

What is a database graph? The partial ordering implies that the set D may now be viewed as a directed acyclic graph, known as a database graph.

Determine the persistent object, Determine the Persistent object Persis...

Determine the Persistent object Persistent object can be stored in one of the following: Files Cheap, permanent, simple storage Low level (Write, Read) Ap

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