Accurate statistics about the data held in tables are used to provide the best execution strategy for SQL queries. but if the statistics don't accurately reflect the current contents of the table you'll get a poorly-performing query. How do you find out if statistics are correct, and what can you do if the automatic update of statistics isn't right for the way a table is used?  Read more...

If you need to optimise SQL Server performance, it pays to understand SQL Server Statistics. Grant Fritchey answers some frequently-asked questions about SQL Server Statistics: the ones we somehow feel silly asking in public, and think twice about doing so.  Read more...

If you need to optimise SQL Server performance, it pays to understand SQL Server Statistics. Grant Fritchey answers some frequently-asked questions about SQL Server Statistics: the ones we somehow feel silly asking in public, and think twice about doing so.  Read more...

In their third live 'Oracle vs. SQL Server' discussion, Jonathan Lewis (Oracle Ace Director, OakTable Network) and Grant Fritchey (Microsoft SQL Server MVP) will look at statistics in Oracle and SQL Server. Expect a lively debate on Oracle vs. SQL Server from two leading RDBMS experts on Jan 23, 2013.  Read more...

In their third live 'Oracle vs. SQL Server' discussion, Jonathan Lewis (Oracle Ace Director, OakTable Network) and Grant Fritchey (Microsoft SQL Server MVP) will look at statistics in Oracle and SQL Server. Expect a lively debate on Oracle vs. SQL Server from two leading RDBMS experts on Jan 23, 2013.  Read more...

In their third live 'Oracle vs. SQL Server' discussion, Jonathan Lewis (Oracle Ace Director, OakTable Network) and Grant Fritchey (Microsoft SQL Server MVP) will look at statistics in Oracle and SQL Server. Expect a lively debate on Oracle vs. SQL Server from two leading RDBMS experts on Jan 23, 2013.  Read more...

In their third live 'Oracle vs. SQL Server' discussion, Jonathan Lewis (Oracle Ace Director, OakTable Network) and Grant Fritchey (Microsoft SQL Server MVP) will look at statistics in Oracle and SQL Server. Expect a lively debate on Oracle vs. SQL Server from two leading RDBMS experts on Jan 23, 2013.  Read more...

How can I find out which statistics are outdated in my SQL Server database?  Read more...

Don't blame SQL Server if your SQL Statements perform badly! But where do you start to investigate the problem? This article is a primer on were to start looking when your SQL runs slowly.  Read more...

It comes as rather a shock to find out that one of the commonest circumstances in an OLTP database, an ascending primary key with most querying on the latest records, can throw the judgement of the Query Optimiser to the extent that perfomance nose-dives. Fabiano Amorim once again dons snorkel and goggles to explore the murky depths of execution plans to find out why.  Read more...

Fabiano Amorim was asked a couple of questions about SQL Server Distribution Statistics. Having given an answer based on his current knowledge, he then decided to find out for himself whether what he'd said was right, and started an epic journey of exploration into Distribution Statistics and the way that the Query Optimiser uses them.  Read more...

Fabiano Amorim was asked a couple of questions about SQL Server Distribution Statistics. Having given an answer based on his current knowledge, he then decided to find out for himself whether what he'd said was right, and started an epic journey of exploration into Distribution Statistics and the way that the Query Optimiser uses them.  Read more...

I have a database which has several tables that have very heavy write operations. These table are very large and some are over a hundred gigabytes. I noticed performance of this database is getting slower and after some investigation we suspect that the Auto Update Statistics function is causing a performance degradation.  Read more...

SQL Server Statistics assist the query optimiser to calculate the best way of running the query. Holger describes every common way that things can go wrong with statistics, and how to put matters right.   Read more...

A free virtual chapter presentation by Andy Warren on Sept 7, 2010 at 12:00EDT. This beginner to intermediate level session will introduce you to statistics, including how to create, manage, troubleshoot, and more!  Read more...

Unlike fine wine, database statistics do not improve with age. I recently helped out with a client who was having...  Read more...

Don't blame SQL Server if your SQL Statements perform badly! But where do you start to investigate the problem? This article is a primer on were to start looking when your SQL runs slowly.  Read more...

Fabiano launches into a sound technical explanation of the way that the query optimiser works in SQL Server with a mention of Brazilian Soccer stars and young ladies on Copacabana beach. You'll never quite think of statistics, execution plans, and the query optimiser the same way again after reading this, but we think you'll understand them better.  Read more...

An in-depth look at index statistics and how they are used by the optimizer by Josef Richberg.   Read more...

With SQL Server 2005 DMVs, we can easily find query performance statistics. Every DBA has a favorite script to find query performance stats. I also have one. But, are all the queries captured by the DMVs? In this tip I will walk through capturing some of this data and show what is capture and what is not captured by the DMVs.  Read more...