Distinct Rows, And The Columns You Choose
Footnote I have two queries. They return the same number of rows. The only difference is one column in the…
2019-05-20
Database Performance
Should Optimistic Be The Default Isolation Level?
Two Words Alright, I’ve lied to you already. There are way more than two words involved, here. I recently had…
2019-05-15
Queries with RECOMPILE and Query Store
Last week in our IEPTO2 class I was asked about queries with RECOMPILE and Query Store. Specifically: Do queries that have the OPTION (RECOMIPLE) hint go into Query...
2019-05-14
SQL Server 2017: here a NUMA, there a NUMA...
The first unexpected behavior is one that may already be familiar to many. [Max server memory] is not as often a maximum for SQL Server [total] memory as it...
2019-05-14
SQL SERVER – Get Last Known Actual Execution Plan for a Previously Cached Query Plan
This feature works with SQL Server 2019 and onwards. If you are using an earlier version of SQL Server this feature will not work and will give you an...
2019-05-11
How to load test a SQL database
How do you know whether a database code change is going to be great, okay or awful? If you want to test a new version of SQL Server how...
The...
2019-05-08
The Only Thing Worse Than Optional Parameters…
Kitchen Stink A lot has been written about “kitchen sink” queries. A couple of my favorites are by Aaron Bertrand…
2019-05-07
Introduction to Wait Statistics
Paul Randal provides a detailed introduction to troubleshooting SQL Server workload performance using wait statistics.
The post Introduction to Wait Statistics appeared first on SQLPerformance.com.
2019-05-07
Query Store, Plan Forcing and Table Variables
This weekend I was in Stockholm in Sweden, talking Query Store and plan forcing with Steinar Anderson, when he mentioned the problems he had while forcing plans that had...
The...
2019-05-06
SQL Server Monitoring Week – SQL Plan Warnings
Today I begin a week-long series where I will be discussing various SQL Server Monitoring Tools. My primary job is to help people with my consulting workshop Comprehensive Database...
2019-04-26
Blogs
Methodology for dealing with bad data in production
By Brian Kelley
Pinal Dave wrote up his methodology for what to do when you discover bad...
How to Provision an Azure SQL Database
Aside from spinning up a SQL Server instance container, the free Azure SQL Database...
Claude finds two cryptographic weaknesses (but the sky isn’t falling)
By Brian Kelley
If you haven't seen the announcement, Anthropic was able to utilize Claude (Mythos Preview)...
Forums
Why SQL Server Database Attach fails and how to repair it
Comments posted to this topic are about the item Why SQL Server Database Attach...
Fixing P1 Queries
Comments posted to this topic are about the item Fixing P1 Queries
BIT_COUNT() IV
Comments posted to this topic are about the item BIT_COUNT() IV
Question of the Day
BIT_COUNT() IV
In SQL Server 2025, I run this code:
select bit_count('A')
What is returned? See possible answers