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 DBA's and programmers improve the performance of their databases. It is not an introduction to SQL, nor is it a tuning manual for a particular SQL implementation. It is a guide for users and programmers who want to improve SQL performance no matter what brand of SQL they use. It will provide tuning tips for common situations, such as how to change a query so it will go faster and how to shift work from the server to the client. All the ideas have been tested against the eight leading DBMS applications. Almost all large organizations and companies today run more than one type of database. This is the only book to cover database tuning for them.
Click below for Sample Chapter(s) related to this title:
Sample Chapter 1
You Don't Know that Your DBMS Is Good….
You Know that Even Good Tools Work Better in Skilled Hands….
This Subject Is Important.
The Big Eight.
Terminology and Expectations.
Code for Points.
Dead Code Elimination.
Ensure You Use the Right DBMS.
The Bottom Line: General Tuning.
AND Plus OR.
The Bottom Line: Specific Tuning.
General Sort Considerations.
The ORDER BY Clause.
To Sort or Not to Sort.
The Bottom Line: General Sorts.
Character Sort Support.
The Bottom Line: Character Sorts.
Encouraging Index Use.
The Bottom Line: Other Options.
Optimal GROUP BY Clauses.
Alternatives to GROUP BY.
The Bottom Line: Optimal GROUP BY Clauses.
The Bottom Line: Sorting.
Set Functions and Summary Aggregates.
Multiple Aggregation Levels.
The Bottom Line: Aggregates.
Join Plan Strategies.
Avoid the Join Strategies
The Bottom Line: Avoiding Joins.
Three-Way Joins and Beyond.
Old Style versus ANSI Style.
Join versus Subquery.
The Bottom Line: Join versus Subquery.
IN or EXISTS?
The Bottom Line: Syntax Choices.
How Big Is the Size Factor?
Fixed or Variable?
The Bottom Line: The Size Factor.
Variant Character Sets.
The Bottom Line: Characters.
The Bottom Line: Temporals.
The Bottom Line: Numbers.
The Bottom Line: Bits.
The Bottom Line: LOBs.
The Bottom Line: NULLs.
Column Order Within Rows.
The Bottom Line: Column Order.
The Storage Hierarchy.
The Bottom Line: Storage Hierarchy.
Free Page Space.
The Bottom Line: Heaps.
The Bottom Line: Clusters.
The Normal Forms.
Breaking Normalization Rules.
The Bottom Line: Normalization.
Bottom Line: Views.
Searching a B-tree.
Inserting into a B-tree.
Deleting from a B-tree.
Rebuilding a B-tree.
The Bottom Line: B-trees.
Types of Indexes.
The Bottom Line: Types of Indexes.
The Bottom Line: Bitmap Indexes.
Other Index Variations.
Index Key Values.
The Bottom Line: Index Key Values.
The Bottom Line: NOT NULL Constraints.
The Bottom Line: CHECK Constraints.
The Bottom Line: FOREIGN KEY Constraints.
The Bottom Line: PRIMARY KEY Constraints.
The Bottom Line: UNIQUE Constraints.
The Bottom Line: Triggers.
The Bottom Line: Disabling Constraints.
The Bottom Line: Client Validations.
Redundant SELECT Clauses.
The Bottom Line: Redundant SELECTs.
Advantages of Stored Procedures.
The Bottom Line: Stored Procedures.
Tracing MS Query.
The Bottom Line: SQLPrepare.
The Bottom Line: Fetch Loops.
The Bottom Line: Data-Change Statements.
The Bottom Line: Catalog Functions.
Connections and DBMS Info.
The Bottom Line: Connections.
The Bottom Line: Query Prepping.
How Many Rows?
The Bottom Line: Result Sets.
The Bottom Line: Data Changes.
The Bottom Line: Logs.
The Bottom Line: INSERT.
The Bottom Line: UPDATE.
The Bottom Line: DELETE.
The Bottom Line: Ugly Updates.
FETCH and Data Changes.
The Bottom Line: FETCH and Data Changes.
COMMIT and ROLLBACK.
The Bottom Line: COMMIT and ROLLBACK.
What Is a Lock?
The Bottom Line: Locks.
Concurrency Problems and Isolation Levels.
READ UNCOMMITTED Transactions.
READ COMMITTED Transactions.
REPEATABLE READ Transactions.
READ ONLY or FOR UPDATE.
The Bottom Line: Isolation Levels.
The Bottom Line: Index Locks.
The Bottom Line: Hot Spots.
The Bottom Line: Optimistic Locking.
The Scan Trick.
The Bottom Line: Middleware.
Server Processes and Threads.
Separateness and Parallelism.
The Bottom Line: Server Processes and Threads.
What Should the Client Do?
The Bottom Line: Client Tips.
Statistics and Histograms.
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.
The purpose of this book is to help you improve the performance of your SQL database. It is not an introduction to SQL syntax, not a tuning manual for a specific SQL implementation, and not a guide to design or data modelling. Instead, we've written it for users and programmers who want to improve SQL performance, no matter what brand of SQL they use. In this book, you'll find tuning tips for common situations. Topics that will give you the flavor include: "How to change a query so it will go faster", "What an index does", and "Shifting work from the server to the client."
Rather than exploiting the unique features of a single DBMS, we're going to give you ideas that are good for all of the major SQL DBMSs. Client/server programmers and consultants need to appreciate what can happen when the DBMS changes, or--the most challenging situation--the DBMS is unknown. So we tested all the ideas in this book on eight well-known DBMSs.
A good DBMS already contains a good optimizer. Yet you have picked up a book that promises to help you do your own tuning. That means that either you don't know something ... or you do know something:
You don't know that your DBMS is good ...
That would be true if you're a student, or new on the job. That would especially be true if you're writing queries or programs that should work on more than one DBMS. You're most likely to encounter one of the DBMSs with the largest market shares (based on figures for the year 2000):
Data from: Gartner Dataquest (May 2001)
You might also run into DBMSs that are popular for web work (like MySQL), for work with Borland products (like InterBase), for desktops (like Access), for mobile and Java interfacing (like Cloudscape), for embedded systems (like Solid), or a host of small fry (like mSQL and gadfly). This book tries to be useful for the common denominator in all products. To use automotive analogies, it's not a "mechanic's guide to tuning the 1999 Cadillac" book, it's a "driver's guide to optimizing performance of modern cars" book—even if you have a manual transmission.
You know that even good tools work better in skilled hands ...
Everybody has heard of sluggish SQL queries, or even whole systems, that some hero(ine) improved with small effort. Usually the improvement is small too, so we will avoid extravagant promises. But we will make you the following guarantees:
One accusation that could be levelled, and to which we plead guilty, is that some of our material is ad-hoc instead of general principles. Of course! There are only a few general principles in DBMS optimization:
Instead of general principals, we will be looking at what can be done with what's likely to be at hand. If we descend sometimes to mere tips and warnings about traps, that's because we've seen over the years that examples of real situations can help people realize what the general rules are. As has often been observed, tips should be based on principles.
The DBMSs that we looked at while preparing this book include IBM DB2, Informix, Ingres II, InterBase, Microsoft SQL Server, MySQL, Oracle, and Sybase (MS-WindowsNT versions). Each was installed and tested using the default switches recommended in the vendors' instructions. To avoid favoring any vendor's idiosyncrasies, all SQL examples in this book are written in ANSI/ISO Standard SQL:1999. Host-language examples are written in C plus ODBC, or Java plus JDBC.
Your DBMS is your pal. We won't counsel you to subvert it, be paranoid about it, or insult it by assuming it's stupid. Rather, as you would with a pal, you should try to get to know it better, and help it to help you.
Click below to download the Index file related to this title: