SQL Performance Explained

before: 'Hmm, I need to do the thing with the data'; hack together SQL in Squirrel until it gives the correct answer; copy SQL into program; think 'it worked in dev and test' when it turns out to be horribly slow in production; sprinkle indexes; see moderate improvements; leave alone.now: 'Hmm, I need to do the thing with the data'; write SQL to get data, bearing in mind table indexes, join criteria, and the ease with which the database optimiser will be able to narrow down to the target data; run explain plans and check costs; remember that I need real data volumes for the explain plans to be representative of production, and repeat; copy SQL into program; never hear about it again.And all in less than two hundred pages which--while they could be quickly summarised as 'use indexes effectively'--don't waste any time with history lessons, edge-cases, or other forms of padding. Throughout this, it still manages to highlight the differences between Oracle, SQL Server, MySQL and PostgreSQL.I can't really offer any criticism here, hence the five stars, but if there is ever going to be a follow up then I'd like to see some coverage of DB2.

Essentially the secret is indexing but creating the correct indexes is still a skill. This book clearly explains how indexing works and how to indentify what indexes are required.Performance is often an afterthought but this book should be essential reading for all developers so that performance considered before it becomes an issue.

I purchased this book principally for learning SQL tunning/Performance for oracle database however the book covers several widely used DBMS such as oracle, PostgreSQL, mysql, sql server, MySQL, . . .The domain is quite vast & as a beginner, if you just check the online oracle documentation, you can hardly find your way. This book opens the door. You learn the basic concepts and terminology (what is a BTree index, how it is read and how it can impact performance). There are many interesting examples, each of them, provided with execution plans.At the end of the book there is a summary of how to read an execution plan (dedicated section for each DBMS)The author uses a simple language and in general it seems that the book addresses principally those who almost don't know much about the performance problems. Yet I believe non beginners can also benefit from the interesting scenarios described in the book for investigating and tackling performance problems (very good & classic examples)The accent has been put on indexes. You will learn different type of indexes, how to improve them, how a database read an index, doing different type of index/table scans, how to investigate the cause of a slow query, etc.Personally I liked the book and I recommend it. I would've preferred to see more details in the book about the meaning of each section of an execution plan. Also it would be more helpful if the author gives more details about hash joins and hash group by.My conclusion: Excellent book and I recommend it.

I have a database with 7.5 million records and I was struggling with a query that was taking about 1 minute, 30 seconds to execute. 43 pages in and it is now executing in 3 seconds.This is exactly the result I was looking for.This is a technical book, aimed specifically at application developers, however it is well written and is not too heavy on the guts of databases.The first part of the book explains indexing very clearly and very simply. It then goes on to highlight the finer points of joins, sorting, clustering etc.Worked for me.

Most useful book I've read, taking into account its size.Bought it only for Sql Server explanations, but learned something about Oracle too.Willing to take profiler and improve, improve, improve...Seriously speaking - coherent explanation of tough stuff and putting into system a lot of fragmentary pieces of knowledge.

Seems to be the right present and new owner is really happy with the book content

An absolute must for anybody who cares about database performance, the guy knows what he's talking about and explains everything clearly and concisely. I could not recommend this book enough.

great value and well packaged