Category: Execution Plans

Execution plans are an important part of understanding database performance.
Jonathan Kehayias starts a new blog series where he tests the impact that a specific plan shape might have on ASYNC_NETWORK_IO waits.
Erin Stellato discusses the performance impact of a predominately adhoc workload in SQL Server.
Paul White explains why the IGNORE_DUP_KEY index option on a clustered index can result in much poorer performance than for a nonclustered unique index.
Aaron Bertrand introduces Scalar UDF Inlining, a long-awaited feature in SQL Server 2019 that will improve the performance of some workloads.
January 22, 2019 | | Execution Plans 0
Jonathan Kehayias shares insight about new UDF information in showplan, and shows that only some tools will show it (SSMS 17+ & SentryOne Plan Explorer).
In the conclusion of his series on grouping and aggregation costs, Itzik Ben-Gan reveals some of the math behind seek vs. scan decisions.
In the fourth installment of his series on optimization thresholds, Itzik Ben-Gan looks at how SQL Server applies costs to parallel operations.
Itzik Ben-Gan dissects the Hash Match (Aggregate) algorithm in his latest post in a series on SQL Server optimization thresholds.
Continuing his series on optimization thresholds, Itzik Ben-Gan dives into the costs behind stream aggregates when the data needs to be sorted first.
For his first post on, Itzik Ben-Gan shows you how to reverse engineer optimizer costing for a Stream Aggregate operator.
Rob Farley describes a tactic where adding multiple predicates around separate date and time columns can win you some better performance.
March 29, 2018 | | Execution Plans, T-SQL 0
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.
March 19, 2018 | | Execution Plans 0
Usually DISTINCT and GROUP BY will yield the same results, but here Rob Farley explains cases that can break the rule.
March 13, 2018 | | Execution Plans, T-SQL 0
Continuing his in-depth series on row goals, Paul White explains both why and how they can impact queries involving anti joins.
March 7, 2018 | | Execution Plans 0

Top Categories

See all
1 2 3 4 5

Get the best SQL query analysis and optimization tool – free!

  • Index Analysis Sandbox
  • Statistics Analysis with Histogram
  • Management Studio Add-in
  • Plan Diagram
  • Deadlocks
  • History and Comments
Free Download Learn More