SQLPerformance.com - SentryOne Team Blog

SQLPerformance.com

SQLPerformance.com is about providing innovative and practical solutions for improving SQL Server performance. Whether you are running a 3rd party application database where very little can be changed, or you are a DBA at a site where getting the application developers to change anything is next to impossible, industry experts including Paul Randal, Jonathan Kehayias, Erin Stellato and Paul White will cover both the "how" and the "why."
Bert Wagner : Join Elimination

Bert Wagner : Join Elimination

For his first guest post on SQLPerformance.com, Bert Wagner describes the pros and cons of join elimination in SQL Server.

Itzik Ben-Gan : Optimization Thresholds : Grouping & Aggregating Data, Part 3

Itzik Ben-Gan : Optimization Thresholds : Grouping & Aggregating Data, Part 3

Itzik Ben-Gan dissects the Hash Match (Aggregate) algorithm in his latest post in a series on SQL Server optimization thresholds.

Tim Radney : The Importance of Baselines

Tim Radney : The Importance of Baselines

Tim Radney goes into detail about why baselines are important, and how metrics you collect now can help you solve future problems.

Itzik Ben-Gan : Optimizer Thresholds : Grouping & Aggregating, Part 2

Itzik Ben-Gan : Optimizer Thresholds : Grouping & Aggregating, Part 2

Continuing his series on optimization thresholds, Itzik Ben-Gan dives into the costs behind stream aggregates when the data needs to be sorted first.

Glenn Berry : Reasons to Upgrade to SQL Server 2017

Glenn Berry : Reasons to Upgrade to SQL Server 2017

Glenn Berry discusses a number of compelling reasons why, if you are choosing between SQL Server 2016 or SQL Server 2017, you should choose the newer version. Continue reading…

Itzik Ben-Gan : Optimizer Thresholds : Grouping & Aggregating, Part 1

Itzik Ben-Gan : Optimizer Thresholds : Grouping & Aggregating, Part 1

For his first post on SQLPerformance.com, Itzik Ben-Gan shows you how to reverse engineer optimizer costing for a Stream Aggregate operator.

Erin Stellato : Automatic Index Management in Azure SQL Database

Erin Stellato : Automatic Index Management in Azure SQL Database

Following up on her post about automatic plan correction, Erin Stellato talks about a new feature in Azure SQL Database: Automatic Index Management.

Rob Farley : Dealing with date and time instead of datetime

Rob Farley : Dealing with date and time instead of datetime

Rob Farley describes a tactic where adding multiple predicates around separate date and time columns can win you some better performance.

Paul White : Row Goals Part 4 : Anti Join Anti Pattern

Paul White : Row Goals Part 4 : Anti Join Anti Pattern

Paul White continues his series on row goals, treating a redundant and problematic TOP (1) that is added to the inner side of an apply anti join.

Rob Farley : When DISTINCT <> GROUP BY

Rob Farley : When DISTINCT <> GROUP BY

Usually DISTINCT and GROUP BY will yield the same results, but here Rob Farley explains cases that can break the rule.

Paul White : Row Goals Part 3 : Anti Joins

Paul White : Row Goals Part 3 : Anti Joins

Continuing his in-depth series on row goals, Paul White explains both why and how they can impact queries involving anti joins.

Glenn Berry : SQL Server and the Spectre/Meltdown Vulnerabilities

Glenn Berry : SQL Server and the Spectre/Meltdown Vulnerabilities

Glenn Berry explains how the Spectre/Meltdown issues (and their patches!) may affect SQL Server performance, and provides a handy list of mitigation steps to keep your servers protected.

Paul White : Row Goals Part 2 : Semi Joins

Paul White : Row Goals Part 2 : Semi Joins

Continuing his series on row goals, Paul White explains how they can impact certain types of semi joins, and how you can spot these effects in showplan and trace flag output.

Erin Stellato : Automatic Plan Correction in SQL Server

Erin Stellato : Automatic Plan Correction in SQL Server

Erin Stellato gives an overview of Automatic Plan Correction in SQL Server 2017 and Azure SQL Database, and assures us that Microsoft is not trying to code us out of jobs.

Paul White : Setting and Identifying Row Goals in Execution Plans

Paul White : Setting and Identifying Row Goals in Execution Plans

Paul White provides some great information about row goals, explaining why they're important to understand when examining why the query optimizer made a certain choice.