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: 38532 itversity
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: 64294 SkillBuilders
Oracle tutorial: Explain plan for query optimization in Oracle PLSQL oracle tutorial for beginners using execution plan to optimize query sql query analyzer sql query cost analysis https://techquerypond.wordpress.com This oracle tutorial show you how to use EXPLAIN PLAN in oracle. This video covers how to check cost of the query from DBMS_XPLAN.DISPLAY . You can find the cost of the query using the Using EXPLAIN PLAN FOR and based on the result you can optimize the query for faster performance. Subscribe on youtube: https://www.youtube.com/channel/UCpiyAesWNYOXSz5GPq8lbkA For more tutorial please visit #techquerypond https://twitter.com/techquerypond
Views: 10717 Tech Query Pond
This Tutorial will explain basics of Oracle 11g EXPLAIN Plan by using this ppt & some hands-on in Oracle 11g R2 Database.This tutorial will include below topics. Understanding EXPLAIN plan. Set up & Use EXPLAIN Plan. Explain PLAN_TABLE & related scripts & DBMS_XPLAN.DISPLAY. Generate & View EXPLAIN Plan. Read & Interpret basics of EXPLAIN Plan. EXPLAIN PLAN limitations.
Views: 160603 Anindya Das
Themis Instructor John Mullins presents some details on interpreting Oracle Database Explain Plan output. For more information visit http://www.themisinc.com
Views: 45025 Themis Education
In this tutorial, you'll learn how to compare queries to know the better performance query..
Views: 95999 radhikaravikumar
Presenter: Maria Colgan, Oracle Corporation The execution plan for a SQL statement can often seem complicated and hard to understand. Determining if the execution plan you are looking at is the best plan you could get or attempting to improve a poorly performing execution plan can be a daunting task, even for the most experienced DBA or developer. This session examines the different aspects of an execution plan, from selectivity to parallel execution, and explains what information you should be gleaming from the plan and how it affects the execution. It offers insight into what caused the Optimizer to make the decision it did as well as a set of corrective measures that can be used to improve each aspect of the plan.
Views: 3914 ODTUG
When you're tuning SQL query there's two important questions to keep in mind: * Have my changes made any difference? * If they have, is performance better or worse? In this video we'll look at how you can use SQL Developer to compare execution plans. This will enable you to differences between them and determine which plan performs better. ============================ The Magic of SQL with Chris Saxon Copyright © 2015 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: 14732 The Magic of SQL
Text version of the video http://csharp-video-tutorials.blogspot.com/2017/04/sql-server-query-plan-cache.html Slides http://csharp-video-tutorials.blogspot.com/2017/04/sql-server-query-plan-cache_12.html All SQL Server Text Articles http://csharp-video-tutorials.blogspot.com/p/free-sql-server-video-tutorials-for.html All SQL Server Slides http://csharp-video-tutorials.blogspot.com/p/sql-server.html All SQL Server Tutorial Videos https://www.youtube.com/playlist?list=PL08903FB7ACA1C2FB All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenkat/playlists?view=1&sort=dd All Dot Net and SQL Server Tutorials in Arabic https://www.youtube.com/c/KudvenkatArabic/playlists In this video we will discuss 1. What happens when a query is issued to SQL Server 2. How to check what is in SQL Server plan cache 3. Things to consider to promote query plan reusability What happens when a query is issued to SQL Server In SQl Server, every query requires a query plan before it is executed. When you run a query the first time, the query gets compiled and a query plan is generated. This query plan is then saved in sql server query plan cache. Next time when we run the same query, the cached query plan is reused. This means sql server does not have to create the plan again for that same query. So reusing a query plan can increase the performance. How long the query plan stays in the plan cache depends on how often the plan is reused besides other factors. The more often the plan is reused the longer it stays in the plan cache. How to check what is in SQL Server plan cache SELECT cp.usecounts, cp.cacheobjtype, cp.objtype, st.text, qp.query_plan FROM sys.dm_exec_cached_plans AS cp CROSS APPLY sys.dm_exec_sql_text(plan_handle) AS st CROSS APPLY sys.dm_exec_query_plan(plan_handle) AS qp ORDER BY cp.usecounts DESC As you can see we have sorted the result set by usecounts column in descending order, so we can see the most frequently reused query plans on the top. usecounts - Number of times the plan is reused objtype - Specifies the type of object text - Text of the SQL query query_plan - Query execution plan in XML format To remove all elements from the plan cache use the following command DBCC FREEPROCCACHE In older versions of SQL Server up to SQL Server 6.5 only stored procedure plans are cached. The query plans for Adhoc sql statements or dynamic sql statements are not cached, so they get compiled every time. With SQL Server 7, and later versions the query plans for Adhoc sql statements and dynamic sql statements are also cached. Things to consider to promote query plan reusability For example, when we execute the following query the first time. The query is compiled, a plan is created and put in the cache. Select * From Employees Where FirstName = 'Mark' When we execute the same query again, it looks up the plan cache, and if a plan is available, it reuses the existing plan instead of creating the plan again which can improve the performance of the query. However, one important thing to keep in mind is that, the cache lookup is by a hash value computed from the query text. If the query text changes even slightly, sql server will not be able to reuse the existing plan. For example, even if you include an extra space somewhere in the query or you change the case, the query text hash will not match, and sql server will not be able find the plan in cache and ends up compiling the query again and creating a new plan. Another example : If you want the same query to find an employee whose FirstName is Steve instead of Mark. You would issue the following query Select * From Employees Where FirstName = 'Steve' Even in this case, since the query text has changed the hash will not match, and sql server will not be able find the plan in cache and ends up compiling the query again and creating a new plan. This is why, it is very important to use parameterised queries for sql server to be able to reuse cached query plans. With parameterised queries, sql server will not treat parameter values as part of the query text. So when you change the parameters values, sql server can still reuse the cached query plan. The following query uses parameters. So even if you change parameter values, the same query plan is reused. Declare @FirstName nvarchar(50) Set @FirstName = 'Steve' Execute sp_executesql N'Select * from Employees where [email protected]', N'@FN nvarchar(50)', @FirstName One important thing to keep in mind is that, when you have dynamic sql in a stored procedure, the query plan for the stored procedure does not include the dynamic SQL. The block of dynamic SQL has a query plan of its own. Summary: Never ever concatenate user input values with strings to build dynamic sql statements. Always use parameterised queries which not only promotes cached query plans reuse but also prevent sql injection attacks.
Views: 24068 kudvenkat
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: 6181 Satish Lodam
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: 5454 SkillBuilders
Exclusive range of revision notes & video lessons available on our site |||--- ClicK LINK To ViSiT ---||| http://www.studyyaar.com/index.php/module/28-query-processing-and-optimization This video clip is part of module available at http://www.studyyaar.com/index.php/learning-program/7-database-management-system-part-2
Views: 81678 StudyYaar.com
Explain plan is a wonderful utility in Oracle PL SQL. It helps you to understand how much cost a query takes to perform based on indexed table or table without index. In this oracle tutorial a full description is given on a table containing huge number of rows first based on index on a column and then without index.
Views: 3695 Subhroneel Ganguly
Have you ever wondered what the difference is between the "filter predicates" or "access predicates" steps listed in execution plans - or even what a predicate is? If so, watch this video to find out! Copyright © 2015 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: 4842 The Magic of SQL
This is a short video about a feature in SQL Developer which alllow any DBA or developer to compare different execution plans of a SQL Statement. My Blog: https://navneetupnejadba.wordpress.com/ Slideshare: https://www.slideshare.net/navneetupneja1/sql-developer-powerful-free-tool-for-developers-and-dbas
Views: 230 Navneet Upneja
How to Solve Row Lock Contention in Oracle Database - Performance Tuning - Oracle DBA Solve Row Lock Contention & Long Running Query in Oracle Database - Performance Tuning Oracle DBA - Performance Tuning Row Lock Contention Please Like, Comment, Subscribe and Share... Boxcut Media.
Views: 6323 BoxCut Media
Learn how to generate execution plan in oracle database in many ways
Views: 3426 OrSkl Academy
You will learn from this video how a SELECT statement is processed in an Oracle Database. You will learn about the a Parse, Execute and Fetch phases in a select statement. 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: 25570 Ramkumar Swaminathan
See how to get execution and explain plans, format and views those plans, use AutoTrace, and Real Time SQL Monitoring for your SQL queries in Oracle SQL Developer.
Views: 2292 Jeff Smith
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: 13741 OracleDBVision
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: 8231 Maria Colgan
An overview of the new Query Explain Plan feature included in the Oracle Coherence 3.7.1 release. Coherence 3.7.1 YouTube Playlist: http://www.youtube.com/user/OracleCoherence#grid/user/856A473B14828BF0 The Oracle Coherence Wiki: http://coherence.oracle.com Coherence on OTN: http://www.oracle.com/technology/products/coherence/ The Coherence Incubator: http://coherence.oracle.com/display/INCUBATOR/ Coherence Discussion Forums: http://forums.oracle.com/forums/forum.jspa?forumID=480 Oracle Exalogic: http://www.oracle.com/exalogic
Views: 4346 OracleCoherence
You're up and running with autotrace, looking at the actual execution plan for a query. Now the real work begins! What is it you're actually looking for in the execution plan? This video shows what you need to investigate and how to use the HotSpot feature of SQL Developer 4.1 to highlight parts of the query you need to pay attention to. ============================ The Magic of SQL with Chris Saxon Copyright © 2015 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: 7916 The Magic of SQL
When you're optimizing SQL queries you need to understand what they're actually doing. Explain plan is a commonly used tool with a major flaw - the reported plan and actual plan can be different! This video demonstrates this with a simple query, showing how autotrace reports the correct execution plan for the SQL statement. ============================ The Magic of SQL with Chris Saxon Copyright © 2015 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: 2312 The Magic of SQL
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: 57634 AllCertifications Tutorials
This video is part of LearnItFirst's Transact-SQL Programming: SQL Server 2008/R2 course. More information on this video and course is available here: http://www.learnitfirst.com/Course161 Many of the ideas in this video will be revisited in chapters 5 and 11, so expect mostly basics here - details will come in later videos. Using the query from the last video, trainer Scott Whigham discusses execution plans. How can you uncover the steps SQL Server went through to arrive at the results? What is SHOWPLAN? Highlights from this video: - What does the execution plan tell us? - How can you look at the execution plan? - Estimated Execution Plan vs. Actual Execution Plan - How does SQL Server choose indexes? - Analyzing and understanding graphical execution plans - Determining costs of the components of execution - Using SHOWPLAN and much more...
Views: 84625 LearnItFirst.com
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: 3087 SkillBuilders
Chris Saxon, an SQL Developer Advocate with Oracle, takes to his kitchen to explain the differences between access and filter in an SQL execution plan.
Views: 647 Oracle Developer Community ArchBeat
Presenter: Carlos Sierra, Oracle Corporation In this session, participants will learn about producing a SQL Trace then a summary TKPROF report. A sample TKPROF is navigated with the audience, where the trivial and the not so trivial is exposed and explained. Execution Plans are also navigated and explained, so participants can later untangle complex execution plans and start diagnosing SQL performing badly.
Views: 582 ODTUG
Learn how to tune SQL. If you're going to tune Oracle SQL statements, you will need to learn how to read an execution plan! See all Free lessons in this tutorial at http://www.skillbuilders.com/sql-tuning-for-beginners-free-tutorial .
Views: 2087 SkillBuilders
Learn how to tune Oracle SQL statements! You'll need to know how to read an execution plan. See all FREE lessons http://www.skillbuilders.com/sql-tuning-for-beginners-free-tutorial
Views: 707 SkillBuilders
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: 1179 SkillBuilders
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Views: 881 Durga Software Solutions