22-25 April 2026 
SQLBits 2015
Estimation and Statistics : The Basis of query optimization
This will be a deep dive into how the optimizer makes its decisions to give you a plan, the things that can go wrong and how you can have influence over these choices.
At the heart of SQL Server is the cost based optimizer. Stop and think about that a minute, the optimizer attempts to give the “best plan” based on the cost of the work undertaken.
How does it know the cost of the work before its done the work ? This isn’t a conundrum, it doesn’t. It estimates! How does it estimate ? That is statistics.
This will be a deep dive into how the optimizer makes its decisions to give you a plan, the things that can go wrong and how you can have influence over these choices.
How does it know the cost of the work before its done the work ? This isn’t a conundrum, it doesn’t. It estimates! How does it estimate ? That is statistics.
This will be a deep dive into how the optimizer makes its decisions to give you a plan, the things that can go wrong and how you can have influence over these choices.
Speakers
Dave Ballantyne's previous sessions
Estimation and Statistics : The Basis of query optimization
This will be a deep dive into how the optimizer makes its decisions to give you a plan, the things that can go wrong and how you can have influence over these choices.
SQL2014 : The all new cardinality estimator
In SQL Server 2014, there have been many changes aimed at giving a more accurate number of rows, and therefore better plans. This session will be a look at these changes, comparing and contrasting with SQL2012/2008 to see how they help.
Query Optimizer Internals : Traceflag fun
The query optimizer is at the heart of SQL Server. Much of the its' internal workings are hidden from the user, but can be revealed by using a selection of undocumented trace flags. This session will be a deep dive into the these internals.
Estimation, Statistics and “Oh My!”
At the heart of SQL Server is the cost based optimizer. This is driven by estimates and they in turn are driven by statistics.
This will be a deep dive into how the optimizer makes its decisions to give you a plan, the things that can go wrong.
SSIS Custom Components
Writing your first SSIS custom components can seem like a very steep learning curve. In this session i shall walk you through a simple skeletal one to start you on your way.
Whats new in Denali-TSQL
A look at the new TSQL functionality within denali
TSQL Techniques - Why and how to tune a routine
An overview of some everyday TSQL tuning techniques.