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
9,688 reads
Performance Tuning
Analyze and Tune SQL Server Statistics
Over the years, SQL Server Statistics have been discussed in countless blog posts, articles, and presentations, and I believe that they will remain a core topic for a while when speaking about performance. Why is that?
2023-10-04
SQL Server Execution Plan Issues when using TOP Clause and Various Parameters
A query is sometimes super fast and sometimes very slow. One of the main reasons for this problem is Parameter Sniffing. There are several approaches to addressing the Parameter Sniffing issue and this article discusses effective methods for handling Parameter Sniffing in SELECT statements containing a TOP clause.
2023-09-18
Comparing Two Execution Plans
This is a short look at a technique that I discovered recently in Management Studio (SSMS). The technique is to compare two graphical execution plans in the tool to understand what they are doing and how two different queries might affect a particular system, both with the image and with the properties' data behind the […]
2023-11-24 (first published: 2021-03-30)
10,732 reads
SQL Server SET STATISTICS IO ON Deep Dive
In this article we look at how to interpret and use the results of STATISTICS IO when tuning SQL Server queries.
2021-02-17
Digging Into Internals
There are plenty of experts that look to teach you about query tuning and the internals of query execution in SQL Server.
2020-07-18
164 reads
A simple use case for Columnstore Indexes in SQL Server
In this article we look at different use cases for columnstore indexes like when performing SQL Server count * queries.
2020-01-17
Optimize Your SQL by Reformulating the Spec
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.
2021-05-07 (first published: 2019-09-12)
5,394 reads
The Basics - Level 1 of the Stairway to Query Store
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 […]
2020-10-07 (first published: 2019-05-13)
6,898 reads
IGNORE_DUP_KEY slower on clustered indexes
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.
2019-04-05
Blogs
Tooling for Success: The Best FinOps Tools and Technologies
By HeyMo0sh
As a DevOps person, I know that to make FinOps successful, you need more...
From Planning to Practice: Setting Up Your FinOps Framework
By HeyMo0sh
As someone who works in DevOps, I’m always focused on creating systems that are...
“We love to debate minutiae”
By Brian Kelley
I am guilty as charged. The quote was in reference to how people argue...
Forums
Restoring On Top II
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SQL Art 2: St Patrick’s Day in SSMS (Shamrock + Pint + Pixel Text)
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Breaking Down Your Work
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Question of the Day
Restoring On Top II
I have a database, DNRTest, that has a number of tables and other objects in it. The other day, I was trying to mock up a test and ran this code on the same server:
-- run yesterday CREATE DATABASE DNRTest2 GO USE DNRTest2 GO CREATE TABLE NewTable (id INT) GOToday, I realize that I need a copy of DNRTest for another mockup, and I run this:
-- run today USE Master BACKUP DATABASE DNRTest TO DISK = 'dnrtest.bak' GO RESTORE DATABASE DNRTest2 FROM DISK = 'dnrtest.bak' WITH REPLACEWhat happens? See possible answers