Performance Tuning

Optimize Your SQL by Reformulating the Spec

• by Phil Jacobs

• SQLServerCentral

• Aggregates
• Arithmetic
• arithmetic expression
• CTE
• math
• Performance Tuning
• PerformanceTuning
• Query Optimization
• Query performance
• Query Tuning
• queryperformance

• Article

As SQL developers, we tend to think of performance tuning in terms of crafting the best table indices, avoiding scalar and table valued functions, and analyzing query plans (among other things). But sometimes going back to the spec and applying some properties of elementary math can be the best way to begin to improve performance of SQL queries which implement mathematical formulas. This article is a case study of how I used this technique to optimize my SQL implementation of the Inverse Simpson Index.

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2019-09-12

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The Basics - Level 1 of the Stairway to Query Store

• by Carlos Robles

• SQLServerCentral

• Performance Tuning
• Query Data Store (QDS)
• Stairway Series

• Stairway Step

Introduction Instead of going straight into the topic of the Query Store, I would like to start this Stairway Series by mentioning a few performance tuning scenarios that are very common to production DBAs. I think most of us have been in one of these situations at some time: An application experiencing slowness after a […]

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2019-05-13

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IGNORE_DUP_KEY slower on clustered indexes

• by DaveConvery

• SQLServerCentral

• Performance Tuning

• DatabaseWeekly

The IGNORE_DUP_KEY option for unique indexes specifies how SQL Server responds to an attempt to INSERT duplicate values: It only applies to tables (not views) and only to inserts. Any insert portion of a MERGE statement ignores any IGNORE_DUP_KEY index setting.

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2019-04-05

Indexed Views – Performance Panacea or Plight

• by DaveConvery

• SQLServerCentral

• Performance Tuning

• DatabaseWeekly

Far too often, an indexed view is created without consideration for the costs of the indexed view. In this article, Jason Brimhall covers some of the more important costs that are frequently overlooked when considering an indexed view as a performance panacea.

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2019-04-05

WhoIsActive In SSMS

• by administrator

• SQLServerCentral

• Performance Tuning

• DatabaseWeekly

Kevin Feasel provides three SSMS keyboard shortcuts for the sp_whoisactive calls he uses most often in day-to-day database development and query tuning work.

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2019-04-02

How to Determine Activity on Each Processor in SQL Server

• by DaveConvery

• SQLServerCentral

• Performance Tuning

• DatabaseWeekly

The contents of the SELECT, WHERE and ORDER BY clauses are all a matter of determining the story you need to tell. I was asked to look into an issue recently where a 40-core SQL Server instance was fully utilizing a one node over all others...

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2019-03-30

Tracking the number of active sessions on a database using SQL Monitor

• by DaveConvery

• SQLServerCentral

• Performance Tuning

• DatabaseWeekly

It’s surprisingly useful to know the number of active sessions on each of the databases on your servers. With a bit of SQL, we can create a custom metric to track how many sessions recently performed reads or writes on a database.

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2019-03-30

Can You Force A Parallel Plan in Query Store?

• by DaveConvery

• SQLServerCentral

• Performance Tuning

• DatabaseWeekly

I love the questions I get when presenting: Can You Force a Parallel Plan in Query Store. I haven’t a clue. The trick I think is going to be in setting up the test. Let’s try it out.

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2019-03-30

An Experiment with Deadlocks

• by DaveConvery

• SQLServerCentral

• Performance Tuning

• DatabaseWeekly

Everything can be fixed with a query hint (*cough* directive), right? If a certain process is consistently causing deadlocks, a simple ROWLOCK hint can be added to prevent it, right?

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2019-03-30

Comparing plans in Management Studio

• by DaveConvery

• SQLServerCentral

• Performance Tuning

• DatabaseWeekly

Previously Gail Shaw looked at using Query Store to compare execution plans, but it’s not the only way that two execution plans can be compared. The other method requires a saved execution plan and the Management Studio execution plan viewer.

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2019-03-30