Cardinality feedback, introduced with Oracle Database 11g, has been significantly enhanced with 12c. Cardinality feedback allows the CBO to learn from a cardinality estimate mistake and re-optimize the execution plan. Learn more in this free SQL Tuning tutorial. See all free Oracle Database tutorials at http://www.skillbuilders.com/free-oracle-tutorials.
Views: 3185 SkillBuilders
What is Cardinality and High Cardinality and Low Cardinality in Oracle SQL Tutorial SQL Tutorial for beginners PLSQL Tutorial PLSQL Tutorial for beginners PL/SQL Tutorial PL SQL Tutorial PL SQL Tutorial for beginners PL/SQL Tutorial for beginners Oracle SQL Tutorial
Views: 1198 TechLake
Tom Kyte introduces adaptive execution plans followed by a demo. "Adaptive Plans" in SQL Tuning Guide" http://www.oracle.com/pls/topic/lookup?ctx=db121&id=TGSQL221 "Controlling Adaptive Optimization" http://www.oracle.com/pls/topic/lookup?ctx=db121&id=TGSQL257 "Generating and Displaying SQL Execution Plans" http://www.oracle.com/pls/topic/lookup?ctx=db121&id=TGSQL271 "Keeping Your Database Secure" http://www.oracle.com/pls/topic/lookup?ctx=db121&id=DBSEG009
Views: 14103 OracleDBVision
This video includes an optional review of the VPD policy execution, then a function is created with intentional errors for learning purposes, and you see how to diagnose, troubleshoot, and correct errors. Prerequisite video: "Using Virtual Private Database with Oracle Database 12c" which contains the setup of the test case. Copyright © 2014 Oracle and/or its affiliates. Oracle® is a registered trademark of Oracle and/or its affiliates. All rights reserved. Oracle disclaims any warranties or representations as to the accuracy or completeness of this recording, demonstration, and/or written materials (the "Materials"). The Materials are provided "as is" without any warranty of any kind, either express or implied, including without limitation warranties of merchantability, fitness for a particular purpose, and non-infringement.
Views: 1287 Oracle Learning Library
In this free tutorial you will learn how to generate and read (interpret) an execution plan in Oracle Databases. See more FREE Oracle Tuning tutorials at http://skillbuilders.com/free-oracle-tutorials. Understanding what the Oracle Database does with your SQL is essential to tuning - and the execution plan is the key. Oracle Certified Master DBA John Watson will provide a brief introduction (4 minutes) - which includes John's tuning methodology, then demonstrate EXPLAIN PLAN, SQL*Plus AUTOTRACE and DBMS_XPLAN.DISPLAY_CURSOR. In the tutorial, John will teach you: - How to read an execution plan - Find the 1st step in the plan - Decipher the order of the steps in the plan - That EXPLAIN PLAN can be very misleading Prerequisites: To get the most from this tutorial, you should: 1 Know how to code SQL 2 Be familiar with SQL*Plus 3 Know - in very general terms - what an execution plan is. 4 Have a basic understanding of the Library Cache (this is where Oracle Database stores parsed SQL statements) 5 Have a basic understanding of the Cost Based Optimizer (this is the part of the database that parses your SQL, creates an execution plan. Hopefully the correct - most efficient - plan).
Views: 66222 SkillBuilders
Anju Garg is an Oracle Ace Associate with over 12 years of experience in IT Industry in various roles. Since 2010, she has been involved in teaching and has trained more than a hundred DBAs from across the world in various core DBA technologies like RAC, Data guard, Performance Tuning, SQL statement tuning, Database Administration etc. She is a regular speaker at Sangam and OTNYathra. She also writes articles for All Things Oracle. She is passionate about learning and has keen interest in RAC and Performance Tuning. She shares her knowledge via her technical blog at http://oracleinaction.com/ ABSTRACT--- To improve optimizer estimates in case of skewed data distribution , histograms can be created. Prior to 12c frequency and height balanced histograms could be created. if no. of buckets >= NDV, frequency histogram is created and the optimizer makes correct estimates. If no. of buckets < NDV, height balanced histogram is created and accuracy of optimizer estimates depends on whether a key value is an endpoint or not. The problem of optimizer misestimates in case of height balanced histograms is resolved to a large extent in Oracle Database 12c by introducing top-frequency and hybrid histograms which are created if no. of buckets < NDV. This webinar explores Pre as well post 12c histograms while highlighting the top-frequency and hybrid histograms introduced in Oracle Database 12c.
Views: 3926 AIOUG North India Chapter
Do you use EXPLAIN PLAN to tune Oracle SQL? Does it always "tell the truth", or does it "lie". (Maybe it's not the whole truth!) In this free tutorial from SkillBuilders' Oracle Certified Master John Watson, you will learn why the execution plan generated by EXPLAIN PLAN can be misleading and what to do about it. After a brief lecture, John demonstrates exactly why. You'll hear about dynamic sampling, adaptive cursor sharing (11g), adaptive execution plans (12c) and of course, bind variables. John demonstrates how bind variables cause misleading execution plans using dbms_xplan.display and dbms_xplan.display_cursor. To get the most from this tutorial, you should have some understanding of hard parse, soft parse, cardinality, histograms. See all SkillBuilders FREE Oracle Database tutorials at http://www.skillbuilders.com/free-oracle-tutorials.
Views: 3481 SkillBuilders
n this video you will understand what is an SQL profile and how does it help in SQL plan generation and execution. The entire course on Interpreting an AWR report is available at udemy https://www.udemy.com/oracle-database-troubleshooting-and-tuning You can use Coupon Code YOUTUBETT for discount Our Upcoming Online Course Schedule is available in the url below https://docs.google.com/spreadsheets/d/1qKpKf32Zn_SSvbeDblv2UCjvtHIS1ad2_VXHh2m08yY/edit#gid=0 Reach us at [email protected]
Views: 2482 Ramkumar Swaminathan
In this video I describe how you can use Oracle's DBMS_XPLAN.DISPLAY_CURSOR to examine the execution plan for a SQL statement that has recently been executed and determine if that plan is optimal or not and where you might be able to optimize it.
Views: 9768 Maria Colgan
For More Tutorials Related To Cisco,CCNA,Microsoft,Oracle,HP,Adobe,IBM,Java And Much More Please Visit This Site http://www.geteveryvideos.com/category/certification-tutorials/
Views: 58152 AllCertifications Tutorials
Oracle Database Release 12cR1's new Automatic Database Optimization (ADO) features now make it possible to automatically locate data within the most appropriate storage tier and at the appropriate compression level based on its usage patterns. Join Oracle Ace Director Jim Czuprynski as he discusses how to take advantage of these features to save crucial Tier 0 and Tier 1 storage space ... and perhaps even improve query and DML performance.
Views: 5526 Database Community
One of the most interesting new features of the Oracle Database Optimizer is the ability to recognize its own mistakes and use execution statistics to automatically improve execution plans. Oracle calls this "Adaptive Optimization" and this talk will focus on how it works. More webinars at: http://www.red-gate.com/oracle-webinars
Views: 7071 Redgate Videos
Learn the new 12c options for creating histograms. See all free video tutorials at http://www.skillbuilders.com/free-oracle-tutorials. In this free tutorial, Oracle Certified Master DBA John Watson demonstrates what histograms do (provide correct cardinality), the difference between histogram types (Frequency and Height Balanced). You will also learn the importance of the auto sample size algorithm in 12c and the new "Hybrid" and "Top Frequency" type histograms.
Views: 3716 SkillBuilders
blog: https://connor-mcdonald.com Want to run your query, but not have the resultant rows come back to your terminal, and slow you down ? Easy in 12.2 with a new setting in SQL Plus ====================================================== Copyright © 2017 Oracle and/or its affiliates. Oracle is a registered trademark of Oracle and/or its affiliates. All rights reserved. Other names may be registered trademarks of their respective owners. Oracle disclaims any warranties or representations as to the accuracy or completeness of this recording, demonstration, and/or written materials (the “Materials”). The Materials are provided “as is” without any warranty of any kind, either express or implied, including without limitation warranties or merchantability, fitness for a particular purpose, and non-infringement.
Views: 506 Connor McDonald
Learn a predictable and repeatable methodology for tuning Oracle SQL statements. Just four steps that you should always follow when tuning an SQL statement. (Note this video does not contain examples of how to apply the four steps, just what the steps are.) Oracle Certified Master John Watson presents. John concludes with a brief overview of how SkillBuilders SQL tuning course provides the information you need to apply the four steps. Learn more about SkillBuilders SQL Tuning course http://skillbuilders.com/oracle-sql-tuning-training 1. What is Oracle doing? (explain plan, trace) 2. Why is Oracle doing it that way? (analyze the execution plan) 3. Is there a better way? Test! 4. If there's a better way, push the CBO towards the better way.
Views: 13641 SkillBuilders
Learn an Oracle Database 12c new performance feature - Adaptive SQL Plans. During execution, Oracle Database can switch the SQL to a new plan. A very powerful corrective measure! But if you don't know about it , how can you possibly tune SQL in Oracle Database 12c? Time to learn 12c!
Views: 5565 SkillBuilders
Lesson 1 in this tuning tutorial Oracle Certified Master DBA John Watson discusses when a SQL should be tuned and why. i.e. Don't waste your time tuning things that will not help.
Views: 802 SkillBuilders
Oracle Database 11g provides a new feature called "feedback based optimization". In this tutorial you will learn what feedback-based optimization is and how it helps Oracle Database 11g performance. One part of nine tutorials dedicated to Oracle 11g Adaptive Cursor Sharing. View all 10 videos for free at SkillBuilders.com/ACS.
Views: 4743 SkillBuilders
Learn how to tune SQL - especially in Data Warehouse environments - with Constraints. Constraints provide critical information to the Cost Based Optimizer in the Oracle Database. Don't drop your constraints for query performance! In these 5 lessons, Oracle Certified Master DBA John Watson will demonstrate how constraints - unique, foreign key, not null - improve the execution plan and thus performance of SQL in an Oracle database. View all 5 lessons, free at http://www.skillbuilders.com/oracle-database-sql-tuning-with-constraints.
Views: 910 SkillBuilders
Learn how and why equivalent SQL statements can have a dramatic effect on performance. Certified Master J Watson demonstrates...See all our free Oracle Database tutorials at http://skillbuilders.com/free-oracle-tutorials. The Oracle Database cost-based optimizer (CBO) should recognize equivalent SQL statements and re-write them into the most efficient form. Well, nothing is perfect - not even Oracle Database. Sometimes the way you write your SQL can have a dramatic effect on performance. Presented by John Watson, Oracle Certified Master DBA. Some experience with SQL tuning is expected.
Views: 1966 SkillBuilders
This Tutorial will explain fundamentals of Oracle AUTOTRACE. Set up & Use AUTOTRACE. Review PLAN & Statistics generated by AUTOTRACE. Understanding Statistics details.
Views: 23281 Anindya Das
Topic: Understanding The Execution Plan In this video (part-1) I have explained - The basics of Oracle Execution Plan - How an Execution Plan Looks from SQL Developer, SQL*Plus - How to use Oracle Explain Plan command - Where else one can find Oracle's Execution Plan apart from PLAN_TABLE - Some Examples of Execution Plan - Using DBMS_XPLAN package to format the output while printing the Execution Plan
Views: 6521 Satish Lodam
To tune a SQL statement, you need to understand the execution plan. Can you identify the 1st step in an execution plan? The 2nd? The 3rd? In this short tutorial, Oracle Certified Master DBA John Watson of SkillBuilders uses a MERGE JOIN to help you understand how to find the order of execution, essential for SQL tuning.
Views: 1232 SkillBuilders
This presentation explains how to use basic hints of Oracle. The series of SQL tuning videos presents performance tuning tips for developers. For presentation used in this video, please visit: https://drive.google.com/drive/folders/0B6EDqGZwjejmWng5VWM3ZEtaNzA?usp=sharing
Views: 10938 anilkumar ghorakavi
Connect with me or follow me at https://www.linkedin.com/in/durga0gadiraju https://www.facebook.com/itversity https://github.com/dgadiraju https://www.youtube.com/c/TechnologyMentor https://twitter.com/itversity
Views: 31798 itversity
This presentation explains how to read explain plans. The series of SQL tuning videos presents performance tuning tips for developers. For presentation used in this video, please visit: https://drive.google.com/drive/folders/0B6EDqGZwjejmWng5VWM3ZEtaNzA?usp=sharing
Views: 6444 anilkumar ghorakavi
Learn Oracle 12c PL/SQL Security features. In this lesson OCM John Watson provides a brief review (including demonstration) of definer and invokers rights. All lessons are Free at https://www.skillbuilders.com/free-oracle-database-tutorials/oracle-database-12c-inherit-privileges-privilege-plsql-security-tutorial-12c-bequeath-views/oracle-database-12c-inherit-privileges-privilege-plsql-security-tutorial-agenda
Views: 296 SkillBuilders
Overview and demo of using a unified audit policy to audit database behaviors, database components, and database users. "Monitoring Database Activity with Auditing" in Oracle Database Security Guide: http://www.oracle.com/pls/topic/lookup?ctx=db121&id=CCHEHCGI "Auditing Database Activity" in Oracle Database 2 Day + Security Guide: http://www.oracle.com/pls/topic/lookup?ctx=db121&id=BCGGIAIC "Keeping Your Oracle Database Secure" in Oracle Database Security Guide: http://www.oracle.com/pls/topic/lookup?ctx=db121&id=CHDCEBFA
Views: 2597 OracleDBVision
In this tutorial you will learn how to tune the oracle 11g performance.
Views: 18307 DBA Pro
Oracle Database SQL Tuning tutorial. Learn what direct and indirect reads are and what impact they have on tuning SQL in Oracle Database. In this free tutorial from www.SkillBuilders.com, Oracle Master DBA John Watson will explain and demonstrate what direct / indirect reads are, pros and cons, why they can cause instability in the performance of your SQL (unpredictable response time), why stored outlines, SQL plan baselines and hints usually don't help. Perhaps most importantly, John will tell you what you can do about it. Intended Audience: Experience Oracle DBA's, developers and anyone with Oracle SQL tuning experience.
Views: 1665 SkillBuilders
Oracle ASM Clustered File system is the next generation file system from Oracle Corp. Besides clustering, it supports replication. In this free tutorial from SkillBuilders and Oracle Certified Master John Watson, John will demonstrate how to configure (and test) ACFS replication. See all 7 lessons in this tutorial, free, at http://www.skillbuilders.com/what-is-oracle-acfs.
Views: 1362 SkillBuilders
This video is an introduction to Oracle SQL Performance Tuning for Developers: http://www.informit.com/store/oracle-sql-performance-tuning-for-developers-livelessons-9780134117027 6+ Hours of Video Instruction The focus of Oracle SQL Performance Tuning for Developers LiveLessons is to illustrate coding techniques that ensure a consistent response time between instances and releases of the Oracle database. This course works closely with performance tuning of actual SQL statements. Description In this video training, Dan Hotka starts out with a complete overview of the Oracle architecture so students can get an understanding how their SQL and applications can take advantage of the computing environment. This course then goes in-depth on understanding and controlling the Explain Plan, which is how and in what order Oracle retrieves data. The discussion includes considerable detail, with SQL examples, on how the optimizers--both rule-based and cost-based, but mostly cost-based--make their decisions. Students will work with a variety of SQL statements, reviewing Explain Plans and making changes to make these SQL statements perform better. Lectures include index design, using hints and coding style to control the Explain Plans, and how to use useful tools such as index monitoring, SQL Trace, and the PL/SQL profiler. This LiveLessons course takes a close look at indexes: how Oracle selects them, why they are sometimes not used, and how to tell if indexes are being used. This course includes Oracle10g, Oracle11g, and Oracle12c SQL tuning topics. Skill Level Intermediate Learn How To Read and understand Explain Plan content Review an Explain Plan and tell quickly if this is a good plan Understand a good index column candidate from a not-so-good candidate Quickly tell the likelihood if your SQL will use an existing index Use coding and a variety of Hints (directives) that can produce better performing SQL Execute and interpret SQL trace output Who Should Take This Course Oracle programmers Oracle database administrators who need additional training on SQL tuning Course Requirements Working knowledge of the SQL query language http://www.informit.com/store/oracle-sql-performance-tuning-for-developers-livelessons-9780134117027
Views: 3181 LiveLessons
Oaktable World 2014 Jonathan Lewis on Calculating Selectivity
Views: 1051 kyle Hailey
Sometimes a poor clustering factor is the cause when Oracle Database cost based optimizer does not choose to use an index. With Oracle 12c (188.8.131.52 EE) offers a new feature that can really help - "Atrribute Clustering". This is implemented with a new keyword on CREATE TABLE - "CLUSTERING BY LINEAR ORDER". In this Free Tutorial from SkillBuilders and Oracle Certified Master DBA John Watson, you'll get a brief refresher on clustering factor and a demonstration of CREATE TABLE - "CLUSTERING BY LINEAR ORDER" - so the CBO will use your index! In this first lesson, John will provide a brief review of clustering factor. See all 6 lessons - FREE - at http://www.skillbuilders.com/12c-attribute-clustering
Views: 385 SkillBuilders
See www.skillbuilders.com/12c-plsql-security for all free modules in this tutorial. It is now in Oracle Database 12c possible to grant roles to the stored program units. Remember this didn't apply to anonymous PL/SQL. Anonymous PL/SQL as always executed with the enabled roles of the invoker. But we can now grant role to a stored procedure. There are a couple of conditions. The role granted must be directly granted to the owner. I'm not sure if this is documented or not or it could've been issues I had during my own testing but certainly the last time I tested this thoroughly I found that if I granted roles to roles to roles to roles as I go down to three, it no longer functions. So that could've been just me or it may be documented. But certainly to be sure, the role granted must be granted directly to the person who's writing the code. Also and it is documented, the owner still needs direct privileges on the object that the code references. That make perfect sense because the role might be disabled at the time that he happens to be creating the object. So you need the role, you need direct privileges on the object referenced by the code. [pause] The invoker however needs absolutely nothing. The invoker now needs nothing, no roles, no privileges. All he needs is execute on the procedure. The invoker will then take on that role during the course of the call. This will tighten up the definer's rights problem and that our user doesn't have much at all. He needs the bare minimum and then only that role will be available, only the role is available to the invoker during the call. Not everything else that the owner happens to have. You can combine this as well with invoker's rights and either way we are controlling privilege inheritance. Invoker's rights plus roles restrict the ability of definer's to inherit privileges from invokers and invokers inherits privileges from definers, both of which raise that ghastly possibility of privilege escalation associated typically to SQL injection. [pause] Grant create session, create procedure to dev, and that will give him select on scott.emp to dev. I've given dev the minimum he needs to write code that hits that table. Then create a role. [pause] Create role r1 and that'll grant select on scott.emp to r1. Finally, grant r1 to dev. It has met the requirements. The role is granted to the owner, the owner does have direct privileges. [pause] So connect as dev/dev and create my favorite procedure. [pause] The same procedure has executed definer's rights and query scott.emp. But now what we can do this new is I can grant r1 to procedure list_emp. [pause] I'll create a very low privileged user now. I need to connect as sysdba and create user low identified by low, and all I shall give him is create session. [pause] And execute on that procedure. [pause] Grant execute on dev.list_emp to low. That's all he's got. He can log on and he can run, run one procedure. What actually is going to happen to him? Let me try to log on. Connect sys low/low set server output on and see if he can run that thing. Just to check, if he tries to select star from scott.emp he is the lowest of the low is my user low. But then execute dev.list_emp, trying to retrieve the CLARKs and it works. And because my user low has virtually no privileges at all, there's no possible danger of the malicious developer being able to inherit dangerous privileges from him. [pause] The final step, that functioned because of the privilege that I mentioned earlier - the privilege that we saw on the previous slide which was inheriting privileges. If I revoke that - and this is what you should be doing in all your systems after upgrade - revoke inherit privileges on user low from public, connect there, and it fails. So the final bit of tightening up the security is to grant the privilege specifically we grant inherit privileges on user low to dev. Now we have a totally secure system and that my low privilege user dev can do that. [pause] And nothing more. My low privileged developer dev can't grab anything in his too as well. That tightens things up totally.
Views: 2874 SkillBuilders
Bulk processing (FORALL and BULK COLLECT), along with the function result cache, are the "big ticket" items when it comes to performance optimization with PL/SQL. But there's still more we can do to tweak our code for even better response times for our users. This third webast in the series starts with the automatic compiler optimization, showcases the extraordinary speediness of PGA data manipulation (a.k.a., package variables), and demonstrates the effect of the simple NOCOPY hint. We finish up with an introduction to pipelined table functions and some thoughts on optimizing your algorithms.
Views: 10680 ODTUG
Learn how to tune SQL with Constraints! In this lesson (3 of 5), OCM John Watson from SkillBuilders demonstrates how to improve query performance by adding not null constraints. See all lessons, free at http://www.skillbuilders.com/oracle-database-sql-tuning-with-constraints.
Views: 404 SkillBuilders
How do you move a datafile in an Oracle Database? Well, it just got a lot easier in 12c! Watch this free video tutorial where OCM John Watson of SkillBuilders will demonstrate both techniques, 11g and 12c. http://skillbuilders.com/free-oracle-tutorials There are many reasons to move a datafile in an Oracle database. Here are just a few: Renaming datafiles to a standard Moving from one file system to another Converting from file system storage to ASM Changing from SAN to NFS storage In 11g, we need to take the tablespace offline, meaning downtime. Argh! In 12c, all that is required is ALTER DATABASE MOVE DATAFILE; this is an online operation with zero downtime (in 11g we use ALTER DATABASE RENAME DATAFILE). Even "critical" files such as the files associated with the SYSTEM tablespace can be moved online. Consider the ease of moving to ASM this provides! This also functions in an Active Data Guard standby environment. And, there are syntax options that allow you to keep or delete the original file. Very cool stuff.
Views: 526 SkillBuilders
Oracle Database Development Web Series is a weeky 1 hour information session. During the session, Oracle Experts will introduce topics ranging from SQL, PL/SQL, JAVA, Node, .NET and how to improve productivity by utilizing Development Tools like SQL Developer, Application Express and much more. Join us every Wednesday at Noon EST. PL/SQL Anti-Patterns We tend to write the same (kind of) code over and over again. Sometimes those patterns are good. Sometimes they are problematic - and then we call them an “anti-pattern”. In this weekly talk (OR WHATEVER YOU CALL IT), Steven will offer up a few anti-patterns, invite attendees to identify the problem, and then shows how to get rid of the “anti”.
Views: 1968 Jeff Smith
Oracle 12c Multi-Threaded Database (parameter threaded_execution=true) provides an fantastic performance improvement by reducing the number of background processes. In this free tutorial, Oracle Certified Master John Watson of SkillBuilders demonstrates how to enable this feature and the resulting performance benefit - in John's demo, a doubling of performance! See all free Oracle 12c tutorials at http://www.skillbuilders.com/free-oracle-tutorials.
Views: 3750 SkillBuilders
This video is the first in a two-part presentation on how to use the Auto DOP feature of Oracle Database 11g, Release 2. Copyright © 2012 Oracle and/or its affiliates. Oracle® is a registered trademark of Oracle and/or its affiliates. All rights reserved. Oracle disclaims any warranties or representations as to the accuracy or completeness of this recording, demonstration, and/or written materials (the "Materials"). The Materials are provided "as is" without any warranty of any kind, either express or implied, including without limitation warranties of merchantability, fitness for a particular purpose, and non-infringement.
Views: 3480 Oracle Learning Library