Tags » SQL Performance

Bug with STATISTICS TIME?

I love the STATISTICS IO and STATISTICS TIME commands. They are such a powerful and easy way to be able to measure improvements when performance tuning ( 775 more words

SQL Performance

Simple Use of TVD$XTAT

Today, I used the TVD$XTAT tool from Christian Antognini to demonstrate to a developer the real reason that their queries were running slow. 534 more words

SQL Performance

10 Cool SQL Optimisations That do not Depend on the Cost Model

Cost Based Optimisation is the de-facto standard way to optimise SQL queries in most modern databases. It is the reason why it is really really hard to implement a complex, hand-written algorithm in a… 8,543 more words

Sql

Setting the Sample Rate for Auto Stats updates

SQL Server functionality can move on pretty quickly sometimes, and it’s not always all about the big features but the many little enhancements the SQL team implements to make the product better and easier to use. 550 more words

Viewing the Statistics Objects Used to Create an Execution Plan

A while ago now I was running some Performance Tuning workshops and was asked how you can find out which Statistics objects SQL Server has used in the generation of an execution plan (for cardinality estimation). 684 more words

Automatic Sample Sizes for Statistics Updates

I mentioned in my previous post about manually updating statistics that you can specify whether they’re updated using a full scan, or you can specify an amount of data to sample, either a percentage of the table size, or a fixed number of rows. 583 more words

Manually updating Statistics

Even though SQL Server automatically updates statistics in the background for you, you may find there are times when you want to manage updating them yourself. 841 more words

SQL Performance