Book Image

Microsoft SQL Server 2012 Performance Tuning Cookbook

Book Image

Microsoft SQL Server 2012 Performance Tuning Cookbook

Overview of this book

As a DBA you must have encountered a slow running application on SQL Server, but there are various factors that could be affecting the performance. If you find yourself in this situation, don't wait, pick up this book and start working towards improving performance of your SQL Server 2012. SQL Server 2012 Performance Tuning Cookbook is divided into three major parts -- Performance Monitoring, Performance Tuning, and Performance Management--that are mandatory to deal with performance in any capacity. SQL Server 2012 Performance Tuning Cookbook offers a great way to manage performance with effective, concise, and practical recipes. You will learn how to diagnose performance issues, fix them, and take precaution to avoid common mistakes. Each recipe given in this book is an individual task that will address different performance aspects to take your SQL Server's Performance to a higher level.The first part of this book covers Monitoring with SQL Server Profiler, DTA, System statistical function, SPs with DBCC commands, Resource Monitor & Reliability, and Performance Monitor and Execution Plan. The second part of the book offers Execution Plan, Dynamic Management Views, and Dynamic Management Functions, SQL Server Cache and Stored Procedure Recompilations, Indexes, Important ways to write effective TSQL, Statistics, Table and Index Partitioning, Advanced Query tuning with Query Hints and Plan Guide, Dealing with Locking, Blocking and Deadlocking and Configuring SQL Server for optimization to boost performance.The third and final part gives you knowledge of performance management with help of Policy Based Management and Management with Resource Governor.
Table of Contents (28 chapters)
Microsoft SQL Server 2012 Performance Tuning Cookbook
Credits
About the Authors
Acknowledgement
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

How to find unused indexes


By this time, it is crystal clear that an index can boost up performance, but it comes at a price. Indexes need space in your desk to accommodate their own B-Tree and get updated each time a DML statement gets executed, so it is a good idea to check for any unused indexes in every business cycle.

Getting ready

Before executing the query to find the unused index, remember that we are going to use a sys.dm_db_index_usage_stats dynamic management view that removes all the data at every restart of a SQL Server instance and starts collecting data from scratch again.

If we just restart the server or SQL Server instance and look for the statistics, it will show that no index is used and will suggest dropping (DROP) all indexes; this is not right. So, keep your SQL Server running for at least one business cycle, and then check for the statistics.

Tip

Business cycles differ from case tocase. Some tables and queries could be in use every day, but some queries for some reports...