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Oracle Hints Tutorial for improving performance
 
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Oracle Hints Tutorial for improving performance APPEND PARALLEL JOIN INDEX NO_INDEX SELECT /*+ FIRST_ROWS(10) */ * FROM emp WHERE deptno = 10; SELECT /*+ ALL_ROWS */ * FROM emp WHERE deptno = 10; SELECT /*+ NO_INDEX(emp emp_dept_idx) */ * FROM emp, dept WHERE emp.deptno = dept.deptno; SELECT /*+ INDEX(e,emp_dept_idx) */ * FROM emp e WHERE e.deptno = 10; -- SELECT /*+ INDEX(scott.emp,emp_dept_idx) */ * FROM scott.emp; SELECT /*+ AND_EQUAL(e,emp_dept_idx) */ * FROM emp e; SELECT /*+ INDEX_JOIN(e,emp_dept_idx) */ * FROM emp e; SELECT /*+ PARALLEL_INDEX(e,emp_dept_idx , 8) */ * FROM emp e; SELECT /*+ LEADING (dept) */ * FROM emp, dept WHERE emp.deptno = dept.deptno; SELECT /*+ PARALLEL(8) CACHE (e) FULL (e) */ * FROM emp e ; SELECT /*+ PARALLEL FULL (e) */ * FROM emp e ; SELECT /*+ PARALLEL USE_MERGE (emp dept) */ * FROM emp, dept WHERE emp.deptno = dept.deptno; -- SORT Merge Join SELECT /*+ PARALLEL USE_HASH (emp dept) */ * FROM emp, dept WHERE emp.deptno = dept.deptno; -- Hash Join SELECT /*+ PARALLEL */ * FROM emp e ; INSERT /*+ APPEND */ INTO mytmp select /*+ CACHE (e) */ *from emp e; commit;
Views: 9375 TechLake
Oracle 11g Hints Overview
 
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In this Video tutorial we will discuss about Optimizer hints in Oracle. What is optimizer hint, when & why its needed. Different Category of hints. Description of mostly used hints. Demonstrate how query plan can change with the influence of hint.
Views: 53690 Anindya Das
Oracle || Indexes Part-1 by dinesh
 
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DURGASOFT is INDIA's No.1 Software Training Center offers online training on various technologies like JAVA, .NET , ANDROID,HADOOP,TESTING TOOLS ,ADF,INFORMATICA,TABLEAU,IPHONE,OBIEE,ANJULAR JS, SAP... courses from Hyderabad & Bangalore -India with Real Time Experts. Mail us your requirements to [email protected] so that our Supporting Team will arrange Demo Sessions. Ph:Call +91-8885252627,+91-7207212428,+91-7207212427,+91-8096969696. http://durgasoft.com http://durgasoftonlinetraining.com https://www.facebook.com/durgasoftware http://durgajobs.com https://www.facebook.com/durgajobsinfo......
B*Tree Index Fundamentals(Indexes in Oracle-1)
 
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Part -1 : Introduction to Indexes, B*Tree Indexes, Index scan methods. Part -2 : B*Tree Index Types(different types of B*Tree indexes) Part -3: Using B*Tree Indexes(When use B*Tree indexes, factors related to B*Tree Access) Part -4 : Index Organized Table Part -5 : Bitmap Indexes Part -6: Partitioned Indexes Part- 7: Other type of Indexes based on characteristics & use. Part -8: Managing Indexes
Views: 49799 Anindya Das
B*Tree Index Types (Indexes in Oracle-2)
 
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This video will cover different types of B-tree indexes: Descending index,Reverse key index,Key Compressed Index B-tree cluster index,Index Organized Table(IOT):
Views: 15551 Anindya Das
Hints
 
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Hints watch more videos at https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Parth Panjab, Tutorials Point India Private Limited
Oracle Hints explained
 
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Oracle Hints
Views: 578 FAKE News
Oracle Hints Tutorial for improving performance with examples
 
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Oracle Hints Tutorial for improving performance with examples Oracle Hints Oracle Tutorial for beginners SQL Tutorial for beginners SQL Hints SQL Performance tuning
Views: 4313 TechLake
Oracle Indexes - Live Demonstration
 
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When is a Full Table Scan faster than an Index Scan? Watch Ross and Jordan act out an Oracle database reading and caching data via both methods, explaining the costs and benefits in simple and easy to understand terms. The demonstration is part of a talk by Ross Leishman of DWS Ltd on the principles of Understanding Indexes for SQL Tuning. The full lecture is at this link: https://www.youtube.com/watch?v=Z4hKomnGHFA DWS Ltd is a leading publicly listed Australian IT Services company, providing services to blue chip organisations since 1991. With a business philosophy based upon integrity, reliability and professional service delivery, DWS provides end to end IT solutions. www.dws.com.au
Views: 2719 DWS Ltd
Which Order Should Columns Go in an Index?: Finding All the Red Sweets Part 4
 
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When you create an index on multiple columns there's an important question you need to answer: In which order should you list the columns? This video looks at some of the factors you should consider to help answer this question. ============================ 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: 4494 The Magic of SQL
Using B*Tree Indexes-When to use B*Tree Indexes(Indexes in Oracle-3)
 
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 This video will cover  When B*Tree Index should be used. We will try to understand some of the situations when the optimizer will use B*Tree Index.  Index Clustering Factor .  Influence of parameter Optimizer_Mode and Optimizer_index_cost_adj on using B*Tree Index.
Views: 13423 Anindya Das
Oracle Database Performance Tuning - Optimizer Statistics Gathering - 11g, 12c
 
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Oracle Database Performance Tuning - Optimizer Statistics Gathering - 11g, 12c In this video we explain how to gather the database optimizer statistics #performancetuning, #oracledatabase, #oracle, #database, #optimizerstatistics, #learning, About Optimizer Statistics Collection In Oracle Database, optimizer statistics collection is the gathering of optimizer statistics for database objects, including fixed objects. The database can collect optimizer statistics automatically. You can also collect them manually using the DBMS_STATS package. Oracle Database Performance Tuning - Optimizer Statistics Gathering - 11g, 12c Purpose of Optimizer Statistics Collection The contents of tables and associated indexes change frequently, which can lead the optimizer to choose suboptimal execution plan for queries. To avoid potential performance issues, statistics must be kept current. To minimize DBA involvement, Oracle Database automatically gathers optimizer statistics at various times. Some automatic options are configurable, such enabling AutoTask to run DBMS_STATS. Oracle Database Performance Tuning - Optimizer Statistics Gathering - 11g, 12c Stats collection Stats gathering database performance tuning, 10g, 11g 12c database administration
Views: 491 KINGS TUBE
Oracle Database Indexes: Myths, Tips and Tricks
 
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In this tutorial, OCM John Watson will - via demonstrations - debunk these myths: Myth #1: Oracle Database does not index NULL Myth #2: A search that includes wildcards can't use an index if the wildcard precedes the string. Myth #3: Oracle will not use a function-based index unless the FBI is coded in the predicate. Myth #4: Indexes always help. The more indexes the better. See http://skillbuilders.com/free-oracle-tutorials for gigabytes of free Oracle video tutorials.
Views: 16386 SkillBuilders
What do you mean the Oracle Optimizer won't use my Index
 
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Learn some details about how the Oracle optimizer works with Themis instructor John Mullins.
Views: 725 Themis Education
Oracle Database 12c: Partitioning Improvements with Tom Kyte
 
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Tom Kyte introduces the new partitioning improvements in Oracle Database 12c, followed by a demo of global index maintenance. For more information: "Asynchronous Global Index Maintenance for Dropping and Truncating Partitions" http://www.oracle.com/pls/topic/lookup?ctx=db121&id=VLDBG14107 "Changes for Very Large Databases and Partitioning in Oracle Database 12c Release 1" http://www.oracle.com/pls/topic/lookup?ctx=db121&id=VLDBG14100 "ALTER INDEX COALESCE Clause" http://www.oracle.com/pls/topic/lookup?ctx=db121&id=SQLRF52782 "DBMS_PART.CLEANUP_GIDX Procedure" http://www.oracle.com/pls/topic/lookup?ctx=db121&id=ARPLS74409
Views: 13945 OracleDBVision
Oracle Interview Question oracle index related questions
 
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Description: Oracle Interview Question - oracle index related questions 1. What is Index? How to create index? 2. What are the types of index? 3. How to find the list of indexes for a given table? 4. Explain B-tree index 5. Explain Bitmap index 6. Explain "Function based" index 7. Explain "Reverse Key" index 8. When to choose what type of index? 9. How to know index is being used? 10. How to monitor index usage? 11. What are the advantages/drawbacks of indes? List of all the SQL and PLSQL interview questions @ https://easy-learning-tech.blogspot.com/p/oracle-sql-plsql-interview-questions.html
Views: 1907 Siva Academy
How Reverse Key B*Tree Index Helps in Certain Cases
 
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When to use Reverse B * Tree Index For Full Course Experience Please Go To http://mentorsnet.org/course_preview?course_id=6 Full Course Experience Includes 1. Access to course videos and exercises 2. View & manage your progress/pace 3. In-class projects and code reviews 4. Personal guidance from your Mentors
Views: 10771 Oresoft LWC
How can I speed up a query if an index cannot help?
 
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blog: connor-mcdonald.com Highlights from the April DBA Office Hours session. Office Hours is 100% free Q&A sessions held every month by Oracle experts to help you succeed with the Oracle suite of technologies. Music: Smells Like Summer - Del (Vlog Music No Copyrighted) Video Link: https://youtu.be/IrkMsqcOjGU
Views: 1390 Connor McDonald
Oracle Hints - FIRST_ROWS - Example
 
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Excerpt from "Oracle sql tuning-advanced" video tutorial training. www.dbvidya.com/course/sql-tuning-advanced/ [email protected] +91 991 2323 000 Oracle Performance Tuning Online Training : http://www.dbvidya.com/course/performance-tuning-for-dba/ Oracle SQL Performance Tuning Training Online : http://www.dbvidya.com/course/sql-tuning-advanced/ Oracle Performance Tuning Videos Tutorial for DBA and Developers : http://www.dbvidya.com/oracle-performance-tuning-videos/ Oracle AWR Tutorial: http://www.dbvidya.com/course/oracle-awr/ Erwin Tool Online Training : http://www.dbvidya.com/course/erwin-tool/ ER Data Modeling Course : http://www.dbvidya.com/course/er-modeling/ Dimensional Modeling Training Online : http://www.dbvidya.com/course/dimensional-modeling/ Oracle Database Blogs : http://www.dbvidya.com/blog/
Views: 265 DbVidya
4  When composite index would be used by Oracle
 
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If there is a composite index on any columns then will oracle use it if we give only few of these columns in where clause?
Partitioning in Oracle Explained with Real project Examples : Introduction
 
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This Video series will explain partitioning and its use cases referencing real project examples from different domain. It will explain what when and why of partitioning in a simple but elaborate manner. This is the 1st video which explains why partitioning is required and what are the advantages we gain from it. The following videos will explain when should we do it and how.
Views: 30013 Tech Coach
SQL: Types of Indexing
 
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In this tutorial, you'll learn how to make use of different indexes...
Views: 33722 radhikaravikumar
SQL: Optimizer Hints Part-1
 
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In this tutorial, you'll learn...what are optimizer hints and how to use it.. SQL (pronounced "ess-que-el") stands for Structured Query Language. SQL is used to communicate with a database. According to ANSI (American National Standards Institute), it is the standard language for relational database management systems.
Views: 20727 radhikaravikumar
Why Use Parallel Processing?
 
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This video compares the use of parallel and serial processing for the same SQL query. 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.
Tune Your Oracle SQL Without Hints or Indexes! - Preview Introduction
 
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“But I can’t change the queries that run in my database,” you say. Not a problem! This webinar we explore the underutilized art of rewriting a SQL query in order to make it run faster. I'll show you how to make your SQL query performance skyrocket simply by changing the SQL text. But even if you truly can't change the SQL, I'll also demonstrate how you can hurdle this issue too. This webinar will be presented by our most active OraPub SLACK member, Kaley Crum! Go Kaley!! This webinar will be on Wed Sept 12th 2018 at 7am PT. For details on how you can see the full webinar or webinar recording post date, go to www.orapub.com
Views: 32 OraPub, Inc.
Why Is My Query Slow? More Reasons Storing Dates as Numbers Is Bad
 
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Storing dates as numbers can cause unexpected problems. In this video Chris looks at one possible issue: inconsistent query performance. He then shows methods you can use to improve performance, including function-based indexes and histograms. ============================ 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: 7577 The Magic of SQL
Oracle Performance Tips - Indexes
 
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Learn about index and types of indexes.
Views: 2372 Saurabh Kumar
[Oracle SQL Performance Tuning: 4/4] Basic Hints and their Usage
 
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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: 11160 anilkumar ghorakavi
Oracle SQL Tutorial : Using execution plan to optimize query in oracle
 
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Oracle SQL Tutorial Oracle tutorial: Explain plan for query optimization in Oracle PLSQL explain plan in oracle performance tuning in oracle oracle tutorial for beginners explain plan in oracle 11g 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: 14228 Tech Query Pond
Oracle: Tune Your SQL Without Hints or Indexes! - Long Introduction
 
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"But I can’t change the queries that run in my database,” you say. Not a problem! This webinar we explore the underutilized art of rewriting a SQL query in order to make it run faster. I'll show you how to make your SQL query performance skyrocket simply by changing the SQL text. But even if you truly can't change the SQL, I'll also demonstrate how you can hurdle this issue too. This webinar will be presented by our most active OraPub SLACK member, Kaley Crum! To watch the full webinar go to www.oraoub.com/webinars
Views: 58 OraPub, Inc.
SQL: Optimizer Hints Part-2
 
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In this tutorial, you'll learn...what are optimizer hints and how to use it.. SQL (pronounced "ess-que-el") stands for Structured Query Language. SQL is used to communicate with a database. According to ANSI (American National Standards Institute), it is the standard language for relational database management systems.
Views: 11962 radhikaravikumar
Partitioning in Oracle - Performance Basics
 
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This is the 2nd video from " Partitioning in Oracle " series, It explains how oracle stores and manages data. What is single Block IO and Multi Block IO ? Why full table scan is better than index access in few cases. The video is very elaborate, I have tried my level best to keep it as simple as possible
Views: 12149 Tech Coach
Oracle || Indexes Part-3 by dinesh
 
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DURGASOFT is INDIA's No.1 Software Training Center offers online training on various technologies like JAVA, .NET , ANDROID,HADOOP,TESTING TOOLS ,ADF,INFORMATICA,TABLEAU,IPHONE,OBIEE,ANJULAR JS, SAP... courses from Hyderabad & Bangalore -India with Real Time Experts. Mail us your requirements to [email protected] so that our Supporting Team will arrange Demo Sessions. Ph:Call +91-8885252627,+91-7207212428,+91-7207212427,+91-8096969696. http://durgasoft.com http://durgasoftonlinetraining.com https://www.facebook.com/durgasoftware http://durgajobs.com https://www.facebook.com/durgajobsinfo......
Stop Rebuilding Global Indexes! Oracle 12c Global Index Maintenance
 
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Stop rebuilding Global Indexes! Stop worrying about invalidating Global Indexes! Oracle 11g gave us "UPDATE GLOBAL INDEXES". 12c provides a huge improvement: orphaned_entries! In this tutorial, Oracle Certified Master John Watson demonstrates how 11g and 12c handle Global Index maintenance with orphaned entries and overnight maintenance job PMO_DEFERRED_GIDX_MAINT_JOB.
Views: 2613 SkillBuilders
SQL: Optimizer Hints Part-3
 
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In this tutorial, you'll learn...what are optimizer hints and how to use it.. SQL (pronounced "ess-que-el") stands for Structured Query Language. SQL is used to communicate with a database. According to ANSI (American National Standards Institute), it is the standard language for relational database management systems.
Views: 10719 radhikaravikumar
Oracle SQL Performance Tuning  1
 
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Oracle SQL Performance Tuning and tips Cost Based Optimizer (CBO) Rule Based Optimizer (RBO) SQL Explain Plan Oracle Explain Plan
Views: 16808 TechLake
SQL Server Index Internals – Multiple Index Hints by SSMS - by Amit Bansal
 
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In this video, you will see that SQL Server can, sometimes, recommend more than one index hint for a given query, but it is not so evident. Video resources including presentation, demo files, code snippets and more learning material is available on http://www.dataplatformgeeks.com/ (Join for free and access all the resources) Connect With The Speaker (Amit Bansal) -Follow on Twitter: https://twitter.com/A_Bansal -Follow on FaceBook at http://www.facebook.com/amit.r.bansal -Follow on LinkedIN: http://www.linkedin.com/in/amitbansal2010 -Facebook Page: https://www.facebook.com/AmitRSBansal/ Connect with SQLMaestros: http://sqlmaestros.com/ -http://www.twitter.com/SQLMaestros -https://www.facebook.com/SQLMaestros -Email us: [email protected] Have technical questions? Join the largest SQL group on FB www.facebook.com/groups/theSQLGeeks Our LinkedIn group https://www.linkedin.com/groups/6753546 DataPlatformGeeks (DPG) Community Join the fastest growing community of data & analytics professionals Why Join DPG? http://www.dataplatformgeeks.com/ -Attend all events hosted by DPG, including SQLMaestros Special Events -Get access to free videos, labs, magazines and host of learning resources -Download all events & conference material -Learn new skills. Sharpen existing skills -Be part of Asia’s Largest Data/Analytics Community -Opportunity to be a regional mentor & speaker at our events -Immense technical & professional development Do you know about Data Platform Summit? http://www.DPS10.com
Views: 723 SQLMaestros
07 06 Index Skip Scan Operations
 
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ORACLE
Views: 928 oracle ocm
Table Partitioning in Oracle Sql|Hash Partitioning|Range Partitioning|List Partitioning|Partitioning
 
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skip_unusable_indexes is NOT skipping unusable indexes!
 
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blog: connor-mcdonald.com Highlights from the April DBA Office Hours session. Office Hours is 100% free Q&A sessions held every month by Oracle experts to help you succeed with the Oracle suite of technologies. Music: Smells Like Summer - Del (Vlog Music No Copyrighted) Video Link: https://youtu.be/IrkMsqcOjGU
Views: 327 Connor McDonald
Using the qb_name Hint in Oracle Database
 
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Oracle ACE Ric Van Dyke shares a tip on using the qb_name hint in Oracle Database, and on how naming query blocks can make debugging a lot easier.
Views: 139 ArchBeat Archive
Oracle Partitioning
 
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Oracle Partitioning watch more videos at https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Parth Panjab, Tutorials Point India Private Limited
What is a Partition in Oracle and Type of Partitions , Range Partition
 
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What is Partition in Oracle and Type of Partitions Range Partition 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: 2953 TechLake
SQL Tutorial For Beginners SQL INDEXES  BITMAP and B-Tree
 
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Oracle SQL Index types with examples. Simple Index, Composite Index, Unique Index, Non Unique Index, Bitmap Index, B-tree Index. SQL Tutorial SQL Tutorial for beginners Oracle SQL Tutorial for beginners
Views: 20934 TechLake
20 Essential Oracle SQL and PL/SQL Tuning Tips
 
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SQL and PL/SQL are powerful languages used to access an Oracle database. Today's databases contain mountains of data which presents itself as a challenge when trying to get to the data we want to in a timely fashion. In this FREE Webinar, OCP DBA John Mullins will present 20 valuable tips to help your SQL or PL/SQL perform better. The tips cover every angle regarding SQL and PL/SQL performance, making the presentation suitable for all job roles. Demonstrations will be used to support many of the tips and Oracle 11g and 12c will be covered.
Views: 41679 Themis Education
Using Parallel and Cardinal Hint
 
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This is a demo on using Parallel and Cardinal Hint to tune queries in ILM.
Views: 1330 Informatica Support
How to create Virtual Columns in Oracle Database
 
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How to create Virtual Columns in Oracle Database 12c When queried, virtual columns appear to be normal table columns, but their values are derived rather than being stored on disc. The syntax for defining a virtual column is listed below. column_name [datatype] [GENERATED ALWAYS] AS (expression) [VIRTUAL] If the datatype is omitted, it is determined based on the result of the expression. The GENERATED ALWAYS and VIRTUAL keywords are provided for clarity only. The script below creates and populates an employees table with two levels of commission. It includes two virtual columns to display the commission-based salary. The first uses the most abbreviated syntax while the second uses the most verbose form. CREATE TABLE employees ( id NUMBER, first_name VARCHAR2(10), last_name VARCHAR2(10), salary NUMBER(9,2), comm1 NUMBER(3), comm2 NUMBER(3), salary1 AS (ROUND(salary*(1+comm1/100),2)), salary2 NUMBER GENERATED ALWAYS AS (ROUND(salary*(1+comm2/100),2)) VIRTUAL, CONSTRAINT employees_pk PRIMARY KEY (id) ); INSERT INTO employees (id, first_name, last_name, salary, comm1, comm2) VALUES (1, 'JOHN', 'DOE', 100, 5, 10); INSERT INTO employees (id, first_name, last_name, salary, comm1, comm2) VALUES (2, 'JAYNE', 'DOE', 200, 10, 20); COMMIT; Querying the table shows the inserted data plus the derived commission-based salaries. SELECT * FROM employees; ID FIRST_NAME LAST_NAME SALARY COMM1 COMM2 SALARY1 SALARY2 ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- 1 JOHN DOE 100 5 10 105 110 2 JAYNE DOE 200 10 20 220 240 2 rows selected. SQL The expression used to generate the virtual column is listed in the DATA_DEFAULT column of the [DBA|ALL|USER]_TAB_COLUMNS views. COLUMN data_default FORMAT A50 SELECT column_name, data_default FROM user_tab_columns WHERE table_name = 'EMPLOYEES'; COLUMN_NAME DATA_DEFAULT ------------------------------ -------------------------------------------------- ID FIRST_NAME LAST_NAME SALARY COMM1 COMM2 SALARY1 ROUND("SALARY"*(1+"COMM1"/100),2) SALARY2 ROUND("SALARY"*(1+"COMM2"/100),2) 8 rows selected. SQL Notes and restrictions on virtual columns include: 1)Indexes defined against virtual columns are equivalent to function-based indexes. 2)Virtual columns can be referenced in the WHERE clause of updates and deletes, but they cannot be manipulated by DML. 3)Tables containing virtual columns can still be eligible for result caching. 4)Functions in expressions must be deterministic at the time of table creation, but can subsequently be recompiled and made non-deterministic without invalidating the virtual column. In such cases the following steps must be taken after the function is recompiled: a)Constraint on the virtual column must be disabled and re-enabled. b)Indexes on the virtual column must be rebuilt. c)Materialized views that access the virtual column must be fully refreshed. d)The result cache must be flushed if cached queries have accessed the virtual column. e)Table statistics must be regathered. 5)Virtual columns are not supported for index-organized, external, object, cluster, or temporary tables. 6)The expression used in the virtual column definition has the following restrictions: a.It cannot refer to another virtual column by name. b.It can only refer to columns defined in the same table. c.If it refers to a deterministic user-defined function, it cannot be used as a partitioning key column. e.The output of the expression must be a scalar value. It cannot return an Oracle supplied datatype, a user-defined type, or LOB or LONG RAW.
Views: 547 OracleDBA
Why Has an Index Broken My Query?
 
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Sometimes Oracle can give unexpected exceptions. This often happens when working with dates stored as strings. In this video, Chris investigates why adding an index to a varchar storing dates could cause a query to fail. He explains why this happens. Then he shows workaround to avoid this. You can download the scripts in this video from LiveSQL at: https://livesql.oracle.com/apex/livesql/file/content_CVN82PZQWQSUFYMOVKG0VI19T.html ============================ 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: 2996 The Magic of SQL
Oracle ||  Index Organized Tables by siva
 
25:46
DURGASOFT is INDIA's No.1 Software Training Center offers online training on various technologies like JAVA, .NET , ANDROID,HADOOP,TESTING TOOLS , ADF, INFORMATICA,TABLEAU,IPHONE,OBIEE,ANJULAR JS, SAP... courses from Hyderabad & Bangalore -India with Real Time Experts. Mail us your requirements to [email protected] so that our Supporting Team will arrange Demo Sessions. Ph:Call +91-8885252627,+91-7207212428,+91-7207212427,+91-8096969696. http://durgasoft.com http://durgasoftonlinetraining.com https://www.facebook.com/durgasoftware http://durgajobs.com https://www.facebook.com/durgajobsinfo............

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