Category : T-SQL - SentryOne Team Blog

Category: T-SQL

Itzik Ben-Gan : Special Islands

Itzik Ben-Gan : Special Islands

Itzik Ben-Gan explains the mechanics behind some different approaches to solving gaps and islands problems in T-SQL.

T-SQL Tuesday #106 : INSTEAD OF triggers

T-SQL Tuesday #106 : INSTEAD OF triggers

For this month's T-SQL Tuesday, Aaron Bertrand shows that when triggers are necessary, in some cases INSTEAD OF triggers can be better for performance than AFTER triggers.

Itzik Ben-Gan : Optimization Thresholds : Grouping and Aggregating Data, Part 5

Itzik Ben-Gan : Optimization Thresholds : Grouping and Aggregating Data, Part 5

In the conclusion of his series on grouping and aggregation costs, Itzik Ben-Gan reveals some of the math behind seek vs. scan decisions.

Itzik Ben-Gan : Optimization Thresholds : Grouping & Aggregating Data, Part 4

Itzik Ben-Gan : Optimization Thresholds : Grouping & Aggregating Data, Part 4

In the fourth installment of his series on optimization thresholds, Itzik Ben-Gan looks at how SQL Server applies costs to parallel operations.

T-SQL Tuesday #104 : Code I Would Hate to Live Without

T-SQL Tuesday #104 : Code I Would Hate to Live Without

For this month's T-SQL Tuesday, Aaron Bertrand talks about his methods for metadata discovery in new versions of SQL Server.

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.

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.

T-SQL Tuesday #102 : Giving Back

T-SQL Tuesday #102 : Giving Back

Aaron Bertrand gives some scattered thoughts about how he has contributed to the SQL Server community throughout his career.

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.

SQLSaturday #724 – Madison, WI

SQLSaturday #724 – Madison, WI

Two of our favorite Andys are gearing up for this weekend's #SQLSatMadison. Here Andy Yun talks about the event, the sessions that he will be presenting, and also talks about Andy Mallon's session.

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.

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.

Bad Habits Revival

Bad Habits Revival

Aaron Bertrand (@AaronBertrand) breathes some new life into his long-running SQL Server series on bad habits and best practices. The latest installment discusses the various impacts of choosing GUIDs over numeric types for keys.

Photo credit: badgreeb_records

T-SQL Tuesday #99: Missing Indexes and Index Key Order

T-SQL Tuesday #99: Missing Indexes and Index Key Order

Don't take SQL Server Missing Index recommendations at face value. They have numerous limitations. In this blog post, Andy Yun explores one of these: Index Key Order.