Call now: 252-767-6166  
Oracle Training Oracle Support Development Oracle Apps

 
 Home
 E-mail Us
 Oracle Articles
New Oracle Articles


 Oracle Training
 Oracle Tips

 Oracle Forum
 Class Catalog


 Remote DBA
 Oracle Tuning
 Emergency 911
 RAC Support
 Apps Support
 Analysis
 Design
 Implementation
 Oracle Support


 SQL Tuning
 Security

 Oracle UNIX
 Oracle Linux
 Monitoring
 Remote s
upport
 Remote plans
 Remote
services
 Application Server

 Applications
 Oracle Forms
 Oracle Portal
 App Upgrades
 SQL Server
 Oracle Concepts
 Software Support

 Remote S
upport  
 Development  

 Implementation


 Consulting Staff
 Consulting Prices
 Help Wanted!

 


 Oracle Posters
 Oracle Books

 Oracle Scripts
 Ion
 Excel-DB  

Don Burleson Blog 


 

 

 


 

 

 
 

Oracle  Find Latest Row

Oracle Database Tips by Donald BurlesonJune 30, 2015

Question: I have a table that contains columns titled last_row, first_row and latest,.  These columns are intended to help track the last row inserted, the first row inserted and the latest row updated.  

Each of these columns has a value of 1 if the condition is met and 0 otherwise (i.e. the most recently inserted row will have 1 in both the last_row and latest columns.  

Is it possible to get multiple entries in the latest column?  If so, how do I protect against it?

Answer:  You only want one row at a time to have the latest column set to 1.  

What you will need to accomplish this is a function-based index on some identifier and decode for latest.  For example:

create table vehicle_positions (vehicle_id number, longitude number,
   latitude number, insert_time date, latest number);
create unique index
   i 
on vehicle_positions
(
vehicle_id,
decode(latest,1,1)
);

This will ensure that there exists one, and only one, vehicle_id associated with a latest column equal to 1; otherwise, Oracle will throw a constraint violation error.  The constraint violation error should be caught and handled with an PL/SQL stored procedure.

 
Get the Complete
Oracle SQL Tuning Information 

The landmark book "Advanced Oracle SQL Tuning  The Definitive Reference"  is filled with valuable information on Oracle SQL Tuning. This book includes scripts and tools to hypercharge Oracle 11g performance and you can buy it for 30% off directly from the publisher.

 


 

 

Burleson is the American Team

Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.  Feel free to ask questions on our Oracle forum.

Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise. All legitimate Oracle experts publish their Oracle qualifications.

Errata?  Oracle technology is changing and we strive to update our BC Oracle support information.  If you find an error or have a suggestion for improving our content, we would appreciate your feedback.  Just  e-mail:  and include the URL for the page.


                    









Burleson Consulting

The Oracle of Database Support

Oracle Performance Tuning

Remote DBA Services


 

Copyright © 1996 -  2016

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.


 

��  
 
 
Oracle Training at Sea
 
 
 
 
oracle dba poster
 

 
Follow us on Twitter 
 
Oracle performance tuning software 
 
Oracle Linux poster