The Hidden Danger of Wildcard Operators In Join Operations
This article looks at one of the killers of performance at scale, SELECT *.
2026-08-14
2,365 reads
Performance
SQL Window Functions Series: LAG() and LEAD()
Dive deep into the powerful SQL window functions, LAG() and LEAD(). Explore their intricacies, discover real-world examples, and avoid common pitfalls.
2023-12-11
12,203 reads
PerfMon: Using SQL Server Performance Counters
Learn how you can use Windows Performance Monitor and the PAL to gather metrics from your SQL Server instances.
2022-07-20
25,220 reads
Automating Extended Events data collection
It’s not difficult to set up an extended event session, but reviewing and saving the data can be complex. In this article, Edward Pollack demonstrates how to collect extended event data.
2021-11-03
SQL Compilations/sec is not what you think it is
SQL Server perfmon counters provide a wealth of information about performance. In this article, Fabiano Amorim shows how current wisdom about one counter, SQL Compilations/sec, can sometimes be misleading.
2021-08-20
SQL Server performance monitor data: Introduction and usage
Monitoring SQL Server for performance is a critical part of a DBA’s job. In this article, Edward Pollack explains some of the SQL Server performance monitor data and how to collect it.
2021-07-21
SQL Server plan cache mining – Plan attributes
Edward Pollack demonstrates how SQL Server plan cache mining can uncover a wealth of information to help with troubleshooting performance issues.
2021-05-21
Efficiently Polling Remote Data Sources
In this article, Edward Pollack describes some of the issues when querying against remote data sources. He covers remote SQL Servers and also connecting to a PostgreSQL database.
2020-10-30
Optimizing Your Query Plans with the SQL Server 2014 Cardinality Estimator
SQL Server 2014 introduces the first major redesign of the SQL Server Query Optimizer cardinality estimation process since version 7.0. The goal for the redesign was to improve accuracy, consistency and supportability of key areas within the cardinality estimation process, ultimately affecting average query execution plan quality and associated workload performance. This paper provides an overview of the primary changes made to the cardinality estimator functionality by the Microsoft query processor team, covering how to enable and disable the new cardinality estimator behavior, and showing how to troubleshoot plan-quality regressions if and when they occur.
2018-06-26
2,974 reads
READ COMMITTED SNAPSHOT ISOLATION and High version_ghost_record_count
Developer shops may decide to use Read Committed Snapshot Isolation (RCSI) to reduce contention, and possibly improve performance, but it is not without its own pitfalls. In this article, Uwe Ricken describes a situation where long running transactions caused a severe performance degradation when RCSI was in use.
2018-03-26
3,103 reads
Blogs
Are Blogs Still Relevant? I Think They Still Are.
As for me, I'll keep writing whenever time permits. I don't expect every post...
Reading Blogs: T-SQL Tuesday #204
By Steve Jones
This is an interesting invitation this month. Jeff Ianucci is a new host, and...
Are Blogs Still Relevant? - T-SQL Tuesday #204
By alevyinroc
T-SQL Tuesday is a monthly blog party hosted by a different community member each...
Forums
Pay for Performance
Comments posted to this topic are about the item Pay for Performance, which is...
Slow - Linked server query
Hi I have this slow query that is pulling data from a linked server....
Too Many Choices
Comments posted to this topic are about the item Too Many Choices
Question of the Day
Too Many Choices
I have a table, dbo.MasterBrands, with this data:
BrandID OfficialName 1 Samsung 2 Apple 3 Microsoft 4 Adidas 5 Coca-ColaI run this query. What is returned for Coca-Cola?
SELECT CHOOSE(BrandID, 'Conglomerate', 'Tech and Design', 'Desktop', 'Apparel') FROM dbo.MasterBrands;See possible answers