Posts by Brent Ozar

Brent Ozar

2790 posts

https://www.brentozar.com

I make Microsoft SQL Server go faster. I love teaching, travel, cars, and laughing. I'm based out of Las Vegas. He/him.

[Video] Office Hours: Back at Home (Briefly)

Last Updated October 1, 2024

Brent Ozar

Videos

I took a break from unpacking my SQL Saturday San Diego bags and re-packing for a Boston wedding long enough to take your top-voted questions from https://pollgab.com/room/brento. Office Hours: Back at Home (Briefly)Watch this video on YouTube Here’s what we covered: 01:55 Deadlockinator: Hi Brent, Why does sp_BlitzWho return NULL in the query_text for some…

How Many Indexes Is Too Many?

Last Updated October 14, 2024

Brent Ozar

Indexing

Let’s start with the Stack Overflow database (any size will work), drop all the indexes on the Users table, and run a delete: Transact-SQL SET STATISTICS IO ON; GO BEGIN TRAN DELETE dbo.Users WHERE DisplayName = N'Brent Ozar'; 1234 SET STATISTICS IO ON;GOBEGIN TRANDELETE dbo.Users WHERE DisplayName = N'Brent Ozar'; I’m using SET STATISTICS IO…

Should That Be One Update Statement or Multiple?

Last Updated October 16, 2024

Brent Ozar

T-SQL

Let’s say we have a couple of update statements we need to run every 15 minutes in the Stack Overflow database, and we’ve built indexes to support them: Transact-SQL EXEC DropIndexes @TableName = N'Users'; CREATE INDEX LastAccessDate ON dbo.Users(LastAccessDate); CREATE INDEX AccountId ON dbo.Users(AccountId); GO BEGIN TRAN /* Give reputation points if folks did something…

[Video] Consulting Lines

Last Updated October 10, 2024

Brent Ozar

Consulting Lines, Videos

In my consulting work, I often find myself saying the same things to clients – but they’re not the kinds of things I said when I was a database administrator. I call these “Consulting Lines”, and I talked through ’em: Consulting LinesWatch this video on YouTube Here’s my full series of Consulting Lines blog…

[Video] Office Hours on a Calm Sea Day Off Canada

Last Updated October 1, 2024

Brent Ozar

Videos

On an unbelievably calm sea day off the shores of Canada, aboard the Norwegian Jewel, I enjoyed a nice cup of completely alcohol-free coffee (as far as you know) and took your top-voted questions from https://pollgab.com/room/brento. Office Hours: Ask Me Anything at SeaWatch this video on YouTube Here’s what we covered: 00:00 Start 01:20 NotCloseEnoughToRetirementToStopLearning:…

Poll: What’s In Your Development Database?

Last Updated October 14, 2024

Brent Ozar

Processes and Practices

When your developers work on new queries or testing complaints about existing queries, what database are they working on? I put together an anonymous one-question poll that only takes a few seconds to respond. Let me know! I’ll follow up with a blog post about the responses.

Finished Your Training? Get a Certificate of Completion.

Last Updated October 8, 2024

Brent Ozar

Conferences and Classes

If you want to get a raise or stand out from a crowd of job hunt competitors, you need something to differentiate yourself. Whenever you finish a training class – including mine – ask if you can get a certificate of completion. For example, here’s what mine look like: You can generate ’em yourself after…

[Video] Office Hours in Haines, Alaska: No Bears Here

Last Updated October 1, 2024

Brent Ozar

Videos

While in beautiful Haines, Alaska along the Chilkoot River, I stopped to take your top-voted questions from https://pollgab.com/room/brento. Office Hours: Ask Me Anything in Haines, AlaskaWatch this video on YouTube Here’s what we covered: 00:00 Start 00:26 James L: When you were an employee, how did you decide whether to move on to another job?…

[Video] Office Hours: Icy Strait Point, Alaska

Last Updated October 1, 2024

Brent Ozar

Videos

I’m on a boat! We took an Alaska cruise with some friends aboard the Norwegian Jewel. En route to Icy Strait Point, Alaska, I took your top-voted questions from https://pollgab.com/room/brento. Office Hours: Ask Me Anything in Icy Strait Point, AlaskaWatch this video on YouTube Here’s what we covered: 00:00 Start 01:40 RollbackIsSingleThread: Hi Brent! If…

This? It's just coffee, as far as you need to know.

Who’s Hiring in the Microsoft Data Platform Community? October 2024 Edition

Last Updated October 1, 2024

Brent Ozar

Who's Hiring

Is your company hiring for a database position as of October 2024? Do you wanna work with the kinds of people who read this blog? Let’s set up some rapid networking here. If your company is hiring, leave a comment. The rules: Your comment must include the job title, and either a link to the…

Announcing the Winners of the Biggest Database Regret Contest

Last Updated October 1, 2024

Brent Ozar

Company News

I recently asked you to leave a comment with your biggest database regret, and the comments were great! Here were my favorites: Runners-Up These 5 folks each won a Fundamentals Bundle lifetime access valued at $695: Thirster42: writing code to help a team dynamically create sequences. they didn’t tell me they were going to generate…

[Video] Office Hours: Open Q&A on Microsoft Databases

Last Updated September 26, 2024

Brent Ozar

Videos

I took your top-voted questions from https://pollgab.com/room/brento while recovering from a late night of partying. Office Hours: Open Q&A on Microsoft DatabasesWatch this video on YouTube Here’s what we covered: 00:00 Start 01:00 VegasDBA: Loved the Always-On Availability Group Episode! You mentioned how awful the dashboard is for monitoring. Can you recommend any scripts, custom…

Free Webcast: How to Think Like the Engine, Big Data Edition

Last Updated September 26, 2024

Brent Ozar

Conferences and Classes

Brent, Big Coat Edition You’ve watched my free How to Think Like the Engine class that focuses on the small 1GB Users table. Let’s take things up a notch by using the ~164GB Posts table full of questions & answers. You’ll learn: What PAGEIOLATCH waits are Why you can’t usually fix them by just adding…

Yes, Cardinality Estimation Keeps Changing After SQL Server 2014.

Last Updated September 26, 2024

Brent Ozar

Execution Plans

About 10 years ago, Microsoft made changes to the Cardinality Estimator (CE) which caused some problems for SQL Server upgrades. When folks upgraded to SQL Server 2014, they also casually switched their databases’ compatibility level to the latest version, because for years that hadn’t really affected query plans. They just figured they wanted the “latest…

TRY/CATCH Doesn’t Always Work.

Last Updated August 16, 2024

Brent Ozar

T-SQL

If you’re using TRY/CATCH to do exception handling in T-SQL, you need to be aware that there are a lot of things it doesn’t catch. Here’s a quick example. Let’s set up two tables – bookmarks, and a process log to track whether our stored proc is working or not: Transact-SQL DROP TABLE IF EXISTS dbo.Bookmarks;…

[Video] Office Hours: Open Q&A About Databases

Last Updated August 8, 2024

Brent Ozar

Videos

I went through your top-voted questions from https://pollgab.com/room/brento plus hit live ones from the TikTok viewers. Office Hours: Ask Me Anything About DatabasesWatch this video on YouTube Here’s what we covered: 00:00 Start 00:52 chandwich: If SSMS had a dark mode option that was equally as good as the existing light mode, would you use…

Query Exercise Answers: Why Are These 3 Estimates So Wrong?

Last Updated August 16, 2024

Brent Ozar

Query Exercise Answers

This week’s Query Exercise challenged you to figure out why these 3 estimates went so badly: Transact-SQL SELECT TOP 250 p.Id, p.Title, COUNT(*) AS VotesCast FROM dbo.Users u INNER JOIN dbo.Posts p ON u.Id = p.OwnerUserId INNER JOIN dbo.Votes v ON p.Id = v.PostId WHERE u.Location = 'Reading, United Kingdom' GROUP BY p.Id, p.Title ORDER…

Contest: What’s Your Biggest Database Regret?

Last Updated August 17, 2024

Brent Ozar

Company News

PAST ME, WHAT WERE YOU THINKING We all make mistakes. I certainly have. I’ll give you a recent one, actually: when we designed the database for SQL ConstantCare®, when we’re storing diagnostic data like wait stats, we thought these 3 columns would be good for identification: user_id server_name instance_name Because a single user would never…

[Video] Office Hours: Database Q&A

Last Updated August 8, 2024

Brent Ozar

Videos

I went live on TikTok and took your top-voted questions from https://pollgab.com/room/brento: Office Hours: Database Q&AWatch this video on YouTube Here’s what we covered: 00:00 Start 00:23 Andrea Hardesty: Do you have any recommendations for reproducing parameter sniffing issues? I have a copy of a production DB. I want @param=222 to use the plan compiled…

Query Exercise: Why Are These 3 Estimates So Wrong?

Last Updated September 18, 2024

Brent Ozar

Query Exercises

Our prior Query Exercise introduced SQL Server’s 201 buckets problem: its inability to accurately estimate rows for more than 201 outliers in a table. I followed up with a solution using filtered statistics to help with the next 200 outliers, and I talked about how that’s really overkill for the simple problem we were facing…