SQL Tuning

Generating Optimal Execution Plans

Author: Dan Tow

Publisher: "O'Reilly Media, Inc."

ISBN: 9780596552367

Category: Computers

Page: 338

View: 9973

A poorly performing database application not only costs users time, but also has an impact on other applications running on the same computer or the same network. SQL Tuning provides an essential next step for SQL developers and database administrators who want to extend their SQL tuning expertise and get the most from their database applications.There are two basic issues to focus on when tuning SQL: how to find and interpret the execution plan of an SQL statement and how to change SQL to get a specific alternate execution plan. SQL Tuning provides answers to these questions and addresses a third issue that's even more important: how to find the optimal execution plan for the query to use.Author Dan Tow outlines a timesaving method he's developed for finding the optimum execution plan--rapidly and systematically--regardless of the complexity of the SQL or the database platform being used. You'll learn how to understand and control SQL execution plans and how to diagram SQL queries to deduce the best execution plan for a query. Key chapters in the book include exercises to reinforce the concepts you've learned. SQL Tuning concludes by addressing special concerns and unique solutions to "unsolvable problems."Whether you are a programmer who develops SQL-based applications or a database administrator or other who troubleshoots poorly tuned applications, SQL Tuning will arm you with a reliable and deterministic method for tuning your SQL queries to gain optimal performance.
Posted in Computers

SQL Performance Tuning

Author: Peter Gulutzan,Trudy Pelzer

Publisher: Addison-Wesley Professional

ISBN: 9780201791693

Category: Computers

Page: 495

View: 3074

A very practical guide to making databases run faster and better. A poorly performing database application can cost each user time, and have an impact on other applications running on the same computer or the same network. This book will help DBAUs and programmers improve the performance of their databases.
Posted in Computers

Oracle SQL Tuning with Oracle SQLTXPLAIN

Oracle Database 12c Edition

Author: Stelios Charalambides

Publisher: Apress

ISBN: 1484224361

Category: Computers

Page: 408

View: 2900

Learn through this practical guide to SQL tuning how Oracle's own experts do it, using a freely downloadable tool called SQLTXPLAIN. This new edition has been expanded to include AWR, Oracle 12c Statistics, interpretation of SQL Monitor reports, Parallel execution, and Exadata-related features. Reading this book and using SQL helps you learn to tune even the most complex SQL, and you'll learn to do it quickly, without the huge learning curve usually associated with tuning as a whole. Firmly based in real-world problems, this book helps you reclaim system resources and avoid the most common bottleneck in overall performance, badly tuned SQL. You'll learn how the optimizer works, how to take advantage of its latest features, and when it's better to turn them off. Best of all, the book is updated to cover the very latest feature set in Oracle Database 12c. Covers AWR report integration Helps with SQL Monitor Report Interpretation Provides a reliable method that is repeatable Shows the very latest tuning features in Oracle Database 12c Enables the building of test cases without affecting production What You'll Learn Identify how and why complex SQL has gone wrong Correctly interpret AWR reports generated via SQLTXPLAIN Collect the best statistics for your environment Know when to invoke built-in tuning facilities Recognize when tuning is not the solution Spot the steps in a SQL statement's execution plan that are critical to performance of that statement Modify your SQL to solve performance problems and increase the speed and throughput of production database systems Who This Book Is For divAnyone who deals with SQL and SQL tuning. Both developers and DBAs will benefit from learning how to use the SQLTXPLAIN tool, and from the problem solving methodology in this book.
Posted in Computers

SQL Server Execution Plans

Author: Grant Fritchey

Publisher: Red Gate Books

ISBN: 9781906434939

Category: Computers

Page: 344

View: 8194

Every day, out in the various online forums devoted to SQL Server, and on Twitter, the same types of questions come up repeatedly: Why is this query running slowly? Why is SQL Server ignoring my index? Why does this query run quickly sometimes and slowly at others? My response is the same in each case: have you looked at the execution plan? An execution plan describes what's going on behind the scenes when SQL Server executes a query. It shows how the query optimizer joined the data from the various tables defined in the query, which indexes it used, if any, how it performed any aggregations or sorting, and much more. It also estimates the cost of all of these operations, in terms of the relative load placed on the system. Every Database Administrator, developer, report writer, and anyone else who writes T-SQL to access SQL Server data, must understand how to read and interpret execution plans.My book leads you right from the basics of capturing plans, through how to interrupt them in their various forms, graphical or XML, and then how to use the information you find there to diagnose the most common causes of poor query performance, and so optimize your SQL queries, and improve your indexing strategy.
Posted in Computers

Microsoft SQL Server 2014 Query Tuning & Optimization

Author: Benjamin Nevarez

Publisher: McGraw Hill Professional

ISBN: 0071829431

Category: Computers

Page: 416

View: 7409

Optimize Microsoft SQL Server 2014 queries and applications Microsoft SQL Server 2014 Query Tuning & Optimization is filled with ready-to-use techniques for creating high-performance queries and applications. The book describes the inner workings of the query processor so you can write better queries and provide the query processor with the quality information it needs to produce efficient execution plans. You’ll also get tips for troubleshooting underperforming queries. In-Memory OLTP (Hekaton), a key new feature of SQL Server 2014, is fully covered in this practical guide. Understand how the query optimizer works Troubleshoot queries using extended events, SQL trace, dynamic management views (DMVs), the data collector, and other tools Work with query operators for data access, joins, aggregations, parallelism, and updates Speed up queries and dramatically improve application performance by creating the right indexes Understand statistics and how to detect and fix cardinality estimation errors Maximize OLTP query performance using In-Memory OLTP (Hekaton) features, including memory-optimized tables and natively compiled stored procedures Monitor and promote plan caching and reuse to improve application performance Improve the performance of data warehouse queries using columnstore indexes Handle query processor limitations with hints and other methods
Posted in Computers

SQL Server Query Performance Tuning

Author: Sajal Dam,Grant Fritchey

Publisher: Apress

ISBN: 1430267429

Category: Computers

Page: 612

View: 8630

Queries not running fast enough? Wondering about the in-memory database features in 2014? Tired of phone calls from frustrated users? Grant Fritchey’s book SQL Server Query Performance Tuning is the answer to your SQL Server query performance problems. The book is revised to cover the very latest in performance optimization features and techniques, especially including the newly-added, in-memory database features formerly known under the code name Project Hekaton. This book provides the tools you need to approach your queries with performance in mind. SQL Server Query Performance Tuning leads you through understanding the causes of poor performance, how to identify them, and how to fix them. You’ll learn to be proactive in establishing performance baselines using tools like Performance Monitor and Extended Events. You’ll learn to recognize bottlenecks and defuse them before the phone rings. You’ll learn some quick solutions too, but emphasis is on designing for performance and getting it right, and upon heading off trouble before it occurs. Delight your users. Silence that ringing phone. Put the principles and lessons from SQL Server Query Performance Tuning into practice today. Covers the in-memory features from Project Hekaton Helps establish performance baselines and monitor against them Guides in troubleshooting and eliminating of bottlenecks that frustrate users
Posted in Computers

Refactoring SQL Applications

Author: Stephane Faroult,Pascal L'Hermite

Publisher: "O'Reilly Media, Inc."

ISBN: 9780596551773

Category: Computers

Page: 298

View: 8219

What can you do when database performance doesn't meet expectations? Before you turn to expensive hardware upgrades to solve the problem, reach for this book. Refactoring SQL Applications provides a set of tested options for making code modifications to dramatically improve the way your database applications function. Backed by real-world examples, you'll find quick fixes for simple problems, in-depth answers for more complex situations, and complete solutions for applications with extensive problems. Learn to: Determine if and where you can expect performance gains Apply quick fixes, such as limiting calls to the database in stored functions and procedures Refactor tasks, such as replacing application code by a stored procedure, or replacing iterative, procedural statements with sweeping SQL statements Refactor flow by increasing parallelism and switching business-inducted processing from synchronous to asynchronous Refactor design using schema extensions, regular views, materialized views, partitioning, and more Compare before and after versions of a program to ensure you get the same results once you make modifications Refactoring SQL Applications teaches you to recognize and assess code that needs refactoring, and to understand the crucial link between refactoring and performance. If and when your application bogs down, this book will help you get it back up to speed.
Posted in Computers

Oracle SQL Performance Tuning and Optimization

It's All about the Cardinalities

Author: Kevin Meade

Publisher: CreateSpace

ISBN: 9781501022692

Category: Computers

Page: 568

View: 7576

Written by a Senior Database Administrator who has worked with the Oracle RDBMS for thirty years, this is a book which teaches the skill of SQL Tuning for the Oracle Database. Not a list of one-off tricks or tips, nor a glossing over of topics; this book offers an in-depth process covering discovery, analysis, and problem resolution. Learn the science behind SQL Tuning. Learn and apply the FILTERED ROWS PERCENTAGE Cardinality based method of tuning Determine a query's Driving Table and Join Order Construct Query Diagrams, Data Models, and Join Trees Build and use Count / Filter / and Reconstruction Queries Identify Waste in a Query Execution Plan Zero in on Cardinality Divergence using Estimated vs. Actuals Use the ACCESS / FILTER / COVERAGE strategy to build indexes for Problem Queries Exploit THE 2% RULE in analyzing Access method and Join method Classify queries as Precision Style or Warehouse Style Understand Hash Join mechanics and make Hash Joins go faster Make HINTS work as Detection Tools rather than clubs Avoid early Database Design flaws Manage Statistics and deal with common Statistics problems (NDV, Uniform Distribution, Independence, Dynamic Sampling) (Staleness, Skew, Dependence, Defaulting, Out-Of-Bounds, Transiency, Bloat) Perfect your Question Based Analyis Technique and more Included are: a special chapter for EXADATA, a LAB which demonstrates the cardinality based process of SQL Tuning, and twenty three magical SQL scripts that make the process of SQL Tuning easy to do. Learn the skill of SQL Tuning as taught by an expert who does it for a living, and become the go-to specialist in your company. Chapter 1: DRIVING TABLE and JOIN ORDER Chapter 2: Ways to Use a Query Execution Plan Chapter 3: The Best Indexes for a Query Chapter 4: JOINS Chapter 5: HINTS Chapter 6: BASICS Chapter 7: ROW COUNTS and RUN TIMES Chapter 8: EXADATA LAB: Reverse Engineering the QEP Appendix: Know Your Scripts Scripts for analyzing queries and plans Scripts for examining an active database Scripts for looking at metadata showplan showplanshort showplanconstraints showplancountqueries showplandatamodel showplandrivingtable showplanfilterqueries showplanfrpspreadsheetcode showplanindexes showplannumrows showplanquerydiagram showplantables showplantablesunique loadplanfromcache loadplanfromhist showtopcpu showowner showindexes showconstraints showcolstats showhistograms showallscanrates showallworkareas It's all about the Cardinalities
Posted in Computers

Oracle Performance Survival Guide

A Systematic Approach to Database Optimization

Author: Guy Harrison

Publisher: Pearson Education

ISBN: 0137000502

Category: Computers

Page: 768

View: 7922

Oracle Performance Survival Guide A Systematic Approach to Database Optimization The fast, complete, start-to-finish guide to optimizing Oracle performance Oracle Performance Survival Guide offers a structured, systematic, start-to-finish methodology for optimizing Oracle performance as efficiently as possible. Leading Oracle expert Guy Harrison shows how to maximize your tuning investment by focusing on causes rather than symptoms, and by quickly identifying the areas that deliver the greatest “bang for the buck.” Writing for DBAs and developers with all levels of experience, Harrison covers every area of Oracle performance management, from application design through SQL tuning, contention management through memory and physical IO management. He also presents up-to-the-minute guidance for optimizing the performance of the Oracle 11g Release 2. You’ll start by mastering Oracle structured performance tuning principles and tools, including techniques for tracing and monitoring Oracle execution. Harrison illuminates the interaction between applications and databases, guides you through choosing tuning tools, and introduces upfront design techniques that lead to higher-performance applications. He also presents a collection of downloadable scripts for reporting on all aspects of database performance. Coverage includes • “Tuning by layers,” the most effective, highest-value approach to Oracle performance optimization • Making the most of Oracle’s core tools for tracing, monitoring, and diagnosing performance • Highly efficient database logical and physical design, indexing, transaction design, and API use • SQL and PL/SQL tuning, including the use of parallel SQL techniques • Minimizing contention for locks, latches, shared memory, and other database resources • Optimizing memory and physical disk IO • Tuning Real Application Cluster (RAC) databases guyharrison.net informit.com/ph
Posted in Computers

The Art of High Performance SQL Code

SQL Server Execution Plans

Author: Grant Fritchey

Publisher: N.A

ISBN: 9781906434021

Category: Computers

Page: 242

View: 4600

Execution plans show you what's going on behind the scenes in SQL Server. They can provide you with a wealth of information on how your queries are being executed by SQL Server, including: Which indexes are being used, and where no indexes are being used at all. How the data is being retrieved, and joined, from the tables defi ned in your query. How aggregations in GROUP BY queries are put together. The anticipated load and the estimated cost that all these operations place upon the system. Grant Fritchey's book is the only in-depth look at how to improve your SQL query performance through careful design of execution plans. Sample chapters of the ebook have garnered stunning reviews, such as: "All I can say is WOW. This has to be the best reference I have ever seen on Execution Plans in SQL Server. My hats off to Grant Fritchey" Jonathan Kehayias.
Posted in Computers

SQL Performance Explained

Everything Developers Need to Know about SQL Performance

Author: Markus Winand

Publisher: N.A

ISBN: 9783950307825

Category: Database management

Page: 196

View: 8938

Posted in Database management

Oracle SQL Tuning Pocket Reference

Write Efficient SQL

Author: Mark Gurry

Publisher: "O'Reilly Media, Inc."

ISBN: 9780596552138

Category: Computers

Page: 110

View: 7132

One of the most important challenges faced by Oracle database administrators and Oracle developers is the need to tune SQL statements so that they execute efficiently. Poorly tuned SQL statements are one of the leading causes of substandard database performance and poor response time. SQL statements that perform poorly result in frustration for users, and can even prevent a company from serving its customers in a timely manner. In this book, Mark Gurry shares his in-depth knowledge of Oracle's SQL statement optimizers. Mark's knowledge is the result of many hard-fought tuning battles during his many years of providing Oracle tuning services to clients. Mark provides insights into the workings of the rule-based optimizer that go well beyond what the rules tell you. Mark also provides solutions to many common problems that occur with both the rule-based and cost-based optimizers. In addition to the specific problem/solution scenarios for the optimizers, Mark provides a number of handy SQL tuning tips. He discusses the various optimizer hints, telling you when they can be used to good effect. Finally, Mark discusses the use of the DBMS_STATS package to manage database statistics, and the use of outlines to specify execution plans for SQL statements in third-party applications that you can't otherwise modify.
Posted in Computers

Oracle Database 12c Release 2 Performance Tuning Tips & Techniques

Author: Richard Niemiec

Publisher: McGraw Hill Professional

ISBN: 1259589692

Category: Computers

Page: 848

View: 2775

Proven Database Optimization Solutions―Fully Updated for Oracle Database 12c Release 2 Systematically identify and eliminate database performance problems with help from Oracle Certified Master Richard Niemiec. Filled with real-world case studies and best practices, Oracle Database 12c Release 2 Performance Tuning Tips and Techniques details the latest monitoring, troubleshooting, and optimization methods. Find out how to identify and fix bottlenecks on premises and in the cloud, configure storage devices, execute effective queries, and develop bug-free SQL and PL/SQL code. Testing, reporting, and security enhancements are also covered in this Oracle Press guide. • Properly index and partition Oracle Database 12c Release 2 • Work effectively with Oracle Cloud, Oracle Exadata, and Oracle Enterprise Manager • Efficiently manage disk drives, ASM, RAID arrays, and memory • Tune queries with Oracle SQL hints and the Trace utility • Troubleshoot databases using V$ views and X$ tables • Create your first cloud database service and prepare for hybrid cloud • Generate reports using Oracle’s Statspack and Automatic Workload Repository tools • Use sar, vmstat, and iostat to monitor operating system statistics
Posted in Computers

Formal SQL Tuning for Oracle Databases

Practical Efficiency - Efficient Practice

Author: Leonid Nossov,Hanno Ernst,Victor Chupis

Publisher: Springer

ISBN: 3662504170

Category: Computers

Page: 109

View: 4535

The target of SQL tuning is the improvement of the existing execution plan. The authors discuss the removal of brakes in the execution plan. Such "brakes" or bottlenecks can be recognized by a formal analysis of the execution plan. For this purpose no data model knowledge is needed. This is especially beneficial for database administrators because they are usually not or insufficiently familiar with the data model. The book presents numerous practical examples with this method.
Posted in Computers

High Performance SQL Server

The Go Faster Book

Author: Benjamin Nevarez

Publisher: Apress

ISBN: 1484222717

Category: Computers

Page: 201

View: 2418

Design and configure SQL Server instances and databases in support of high-throughput applications that are mission-critical and provide consistent response times in the face of variations in user numbers and query volumes. Learn to configure SQL Server and design your databases to support a given instance and workload. You’ll learn advanced configuration options, in-memory technologies, storage and disk configuration, and more, all toward enabling your desired application performance and throughput. Configuration doesn’t stop with implementation. Workloads change over time, and other impediments can arise to thwart desired performance. High Performance SQL Server covers monitoring and troubleshooting to aid in detecting and fixing production performance problems and minimizing application outages. You'll learn a variety of tools, ranging from the traditional wait analysis methodology to the new query store, and you'll learn how improving performance is really an iterative process. High Performance SQL Server is based on SQL Server 2016, although most of its content can be applied to prior versions of the product. This book is an excellent complement to performance tuning books focusing on SQL queries, and provides the other half of what you need to know by focusing on configuring the instances on which mission-critical queries are executed. Covers SQL Server instance-configuration for optimal performance Helps in implementing SQL Server in-memory technologies Provides guidance toward monitoring and ongoing diagnostics What You Will Learn Understand SQL Server's database engine and how it processes queries Configure instances in support of high-throughput applications Provide consistent response times to varying user numbers and query volumes Design databases for high-throughput applications with focus on performance Record performance baselines and monitor SQL Server instances against them Troubleshot and fix performance problems Who This Book Is For SQL Server database administrators, developers, and data architects. The book is also of use to system administrators who are managing and are responsible for the physical servers on which SQL Server instances are run.
Posted in Computers

Inside the SQL Server Query Optimizer

Author: Benjamin Nevarez

Publisher: N.A

ISBN: 9781906434601

Category: Computers

Page: 272

View: 4605

The SQL Server Query Optimizer is perceived by many to be a magic black box, transforming SQL queries into high performance execution plans in the blink of an eye through some unknowable process. The truth is that, while the Query Optimizer is indeed the highly-complex result of decades of research, learning how it works its magic is not only possible, but immensely useful to DBAs and Developers alike. A better understanding of what the Query Optimizer does behind the scenes can help you to improve the performance of your databases and applications, and this book explains the core concepts behind how the SQL Server Query Optimizer works. With this knowledge, you'll be able to write superior queries, provide the Query Optimizer with all the information it needs to produce efficient execution plans, and troubleshoot the cases when the Query Optimizer is not giving you the best plan possible. With over 15 years of experience in the use of Relational Databases (including SQL Server since version 6.5), Benjamin has watched the SQL Server Query Optimizer grow and evolve. His insight will leave you with an excellent foundation in the practicalities of the Query Optimizer, and everything you need to know to start tuning your queries to perfection.
Posted in Computers

Optimizing Oracle Performance

A Practitioner's Guide to Optimizing Response Time

Author: Cary Millsap,Jeff Holt

Publisher: "O'Reilly Media, Inc."

ISBN: 1449366783

Category: Computers

Page: 418

View: 1334

Oracle system performance inefficiencies often go undetected for months or even years--even under intense scrutiny--because traditional Oracle performance analysis methods and tools are fundamentally flawed. They're unreliable and inefficient.Oracle DBAs and developers are all too familiar with the outlay of time and resources, blown budgets, missed deadlines, and marginally effective performance fiddling that is commonplace with traditional methods of Oracle performance tuning. In this crucial book, Cary Millsap, former VP of Oracle's System Performance Group, clearly and concisely explains how to use Oracle's response time statistics to diagnose and repair performance problems. Cary also shows how "queueing theory" can be applied to response time statistics to predict the impact of upgrades and other system changes.Optimizing Oracle Performance eliminates the time-consuming, trial-and-error guesswork inherent in most conventional approaches to tuning. You can determine exactly where a system's performance problem is, and with equal importance, where it is not, in just a few minutes--even if the problem is several years old.Optimizing Oracle Performance cuts a path through the complexity of current tuning methods, and streamlines an approach that focuses on optimization techniques that any DBA can use quickly and successfully to make noticeable--even dramatic--improvements.For example, the one thing database users care most about is response time. Naturally, DBAs focus much of their time and effort towards improving response time. But it is entirely too easy to spend hundreds of hours to improve important system metrics such as hit ratios, average latencies, and wait times, only to find users are unable to perceive the difference. And an expensive hardware upgrade may not help either.It doesn't have to be that way. Technological advances have added impact, efficiency, measurability, predictive capacity, reliability, speed, and practicality to the science of Oracle performance optimization. Optimizing Oracle Performance shows you how to slash the frustration and expense associated with unraveling the true root cause of any type of performance problem, and reliably predict future performance.The price of this essential book will be paid back in hours saved the first time its methods are used.
Posted in Computers

Oracle Tuning: The Definitive Reference

Author: Donald K. Burleson

Publisher: Rampant Techpress

ISBN: 9780982306130

Category: Computers

Page: 828

View: 9639

Oracle has become the world's most flexible and robust database and along with great power comes great complexity. This complexity requires that the DBA have expert knowledge of Oracle internals. This book provides a thorough step-by-step approach for holistic Oracle tuning in this challenging information technology era. It represents the knowledge accumulated from tuning thousands of Oracle databases. Oracle tuning has always been a complex task; however, it has become even more complex as Oracle evolves and yields new techniques for achieving optimal performance in the stressed production environment of today's high-tech world. Oracle STATSPACK and AWR has introduced a revolution in database tuning. By understanding these time-series tables, we can develop time-series tuning models to predict upcoming outages and dynamically change the instance to accommodate the impending resource changes. Database tuning efforts must become as sophisticated as the databases themselves. This book strives to show you how to leverage upon the wealth of Oracle performance information so that you can create a robust Oracle database engine, one that maximizes computing resources while minimizing overhead. If you are seeking theory, this is not the book for you. This book encapsulates the combined knowledge of over a century of hands-on DBA tuning experience, a pragmatic, practical approach for the professional Oracle DBA. This is not a book for beginners. Targeted at the senior Oracle DBA, this comprehensive book gives you all of the knowledge you need to be successful in tuning even the most complex Oracle database. The code download for this book is packed with ready-to-run scripts to monitor and identify even the most challenging performance issues.
Posted in Computers

Senior Leadership Teams

What It Takes to Make Them Great

Author: Ruth Wageman,Debra A. Nunes,James A. Burruss,J. Richard Hackman

Publisher: Harvard Business Review Press

ISBN: 1633692043

Category: Business & Economics

Page: 272

View: 3934

An organisation's fate hinges on its CEO—right? Not according to the authors of Senior Leadership Teams. They argue that in today's world of neck-snapping change, demands on leaders in top roles are rapidly outdistancing the capabilities of any one person - no matter how talented. Result? Chief executives are turning to their enterprise's senior leaders for help. Yet many CEOs stumble when creatinga leadership team. One major challenge is that senior executives often focus more on their individual roles than on the top team's shared work. Without the CEO's careful attention to setting the team up correctly, these high-powered managers often have difficulty pulling together to move their organisation forward. Sometimes they don't even agree about what constitutes the right path forward.The authors explain how to determine whether your organisation needs a senior leadership team. Then, drawing on their study of 100+ top teams from around the world, they explain how to create a clear and compelling purpose for your team, get the right people on it, provide structure and support, and sharpen team members' competencies - and your own. Timely and practical, this book enables you to create and sustain a leadership team whose members learn from one another while collaborating to pursue your company's objectives.
Posted in Business & Economics