Skip to Content
Oracle SQL Tuning with Oracle SQLTXPLAIN: Oracle Database 12c Edition, Second Edition
book

Oracle SQL Tuning with Oracle SQLTXPLAIN: Oracle Database 12c Edition, Second Edition

by Stelios Charalambides
April 2017
Intermediate to advanced
436 pages
12h 7m
English
Apress
Content preview from Oracle SQL Tuning with Oracle SQLTXPLAIN: Oracle Database 12c Edition, Second Edition

© Stelios Charalambides  2017

Stelios Charalambides, Oracle SQL Tuning with Oracle SQLTXPLAIN, 10.1007/978-1-4842-2436-6_12

12. Directives and Statistics Feedback

Stelios Charalambides1 

(1)New Hampton, New Hampshire, USA

In 11g there was a feature called Cardinality Feedback. This reoptimized (hard parsed) a query if the Cardinality Estimate of the final result was more than a certain factor out from the actual result. This was a nice simple feature that was easy to understand. If you saw this note at the end of an execution plan, you knew that Cardinality Feedback had been used.

SQL> select * from table(dbms_xplan.display_cursor(null,null,'ALLSTATS LAST'));PLAN_TABLE_OUTPUTSQL_ID  gtukt6kw8yjm6, child number 3------------------------------------- ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

AirBnbBlueOriginElectronic ArtsHomeDepotNasdaqRakutenTata Consultancy Services
QuotationMarkO’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
QuotationMarkI wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
QuotationMarkI’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
QuotationMarkI'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Mark W.
Embedded Software Engineer

You might also like

Practical Oracle SQL: Mastering the Full Power of Oracle Database

Practical Oracle SQL: Mastering the Full Power of Oracle Database

Kim Berg Hansen
Oracle Database 11g Oracle Real Application Clusters Handbook, 2nd Edition, 2nd Edition
Advanced Oracle PL/SQL Developer's Guide (Second Edition) - Second Edition
Pro Oracle Database 12c Administration, Second Edition

Publisher Resources

ISBN: 9781484224359Purchase book