dcsimg
Login | Register   
RSS Feed
Download our iPhone app
TODAY'S HEADLINES  |   ARTICLE ARCHIVE  |   FORUMS  |   TIP BANK
Browse DevX
Sign up for e-mail newsletters from DevX

By submitting your information, you agree that devx.com may send you DevX offers via email, phone and text message, as well as email offers about other products and services that DevX believes may be of interest to you. DevX will process your information in accordance with the Quinstreet Privacy Policy.


Tip of the Day
Language: Enterprise
Expertise: Advanced
May 16, 2000

WEBINAR:

On-Demand

Application Security Testing: An Integral Part of DevOps


Faster Data Access Using Index-Organized Tables

If you have a table whose columns always are queried together, maybe you should store them as an index-organized table (IOT). An IOT is indexed on one or more columns and all the table data is maintained as a B*tree index. Any manipulation of table data updates the index. The data rows are built on the primary key for the table.

IOTs provide faster data access to queries that involve exact matches or range searches or both. Also, the storage requirement gets reduced because, unlike normal tables, IOTs don't require separate indexes.

A simple statement for creating an IOT is:

 create table table_name ( col1 number primary key, col2 varchar2(20))
	 ORGANIZATION INDEX;
However, IOTs also have some restrictions. They do not support Distribution or Replication, and cannot have UNIQUE constraints on the table.
Jayanta Sengupta
 
Comment and Contribute

 

 

 

 

 


(Maximum characters: 1200). You have 1200 characters left.

 

 

Sitemap
×
We have made updates to our Privacy Policy to reflect the implementation of the General Data Protection Regulation.
Thanks for your registration, follow us on our social networks to keep up-to-date