Posts by Brent Ozar

Brent Ozar

2781 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.

Yet Another Way Missing Index Requests are Misleading

Last Updated July 2, 2019

Brent Ozar

Indexing

Graduates of my Mastering Index Tuning class will already be familiar with the handful of ways the missing index DMVs and plan suggestions are just utterly insane. Let’s add another oddity to the mix: the usage counts aren’t necessarily correct, either. To prove it, Let’s take MattDM’s Stack Exchange query, “Who brings in the crowds?” He’s…

Poll: what’s in your development database?

Last Updated July 1, 2019

Brent Ozar

SQL Server

When the developers at your company are working on building an app, where do they work? Production, a development database restored from production, or a development database with made-up contents? One-question poll, and you can watch the live results. I’ll post the results and my thoughts on Friday. I know what I see regularly out…

4 Ways to Move Data Into a Reporting Server

Last Updated June 26, 2019

Brent Ozar

Architecture

You’ve decided that you need to offload reports to a different SQL Server, and you’re willing to pay the costs. Here are the most common ways to move the data from production to a reporting server, arranged roughly from easiest-to-implement to hardest: 1. Log shipping. Log shipping is more of a technique than a feature:…

Things to Think About When Your Databases Grow Quickly

Last Updated June 22, 2019

Brent Ozar

Production Database Administration

In SQL ConstantCare®, we’re adding a notification for when your data size grows >10% in a single week. When this happens, you want to stop for a second to ask yourself a few questions: Did someone just create a backup table? Folks often do a SELECT INTO to back up an important table right before…

Brace Yourself for These 9 Database Horror Stories

Last Updated June 22, 2019

Brent Ozar

Humor

Last week, I asked for your worst database horror stories. Hoowee, did you deliver. Make yourself a nice cup of cocoa, gather around the campfire, and listen up for these terrible tales. Illustrations courtesy of Swear Trek (not safe for work.) The mistake we’ve all made Russ did an update without a where clause, but…

What the Arrow Sizes in Query Plans Really Mean

Last Updated June 21, 2019

Brent Ozar

Execution Plans

Precisely 80.3% of you are going to learn something in this post. Earlier this week, I asked what you thought the arrows in estimated and actual query plans meant. I asked you to just guess without doing any research, and here’s what you answered: There are a lot of different opinions, and I can see…

Poll: What Do You Think The Arrow Sizes in Query Plans Mean?

Last Updated June 18, 2019

Brent Ozar

Execution Plans

Don’t read the documentation – just guess. What do you think the arrow sizes in query plans mean in SSMS 17/18? After you take the poll – just guess – then you can see what other people think. Friday, I’ll share a demo you can use to prove the answer.

Contest: What’s Your Worst Database Horror Story?

Last Updated March 25, 2020

Brent Ozar

Humor

121

At SQL Intersection in Orlando last week, a few of us were sitting around a table talking shop. One thing led to another, and as so often happens at conferences, we started talking about our worst scars from database misfortunes. That got me thinking – I could kinda bring that fun experience to y’all here…

Forced Parameterization Doesn’t Work on Partially Parameterized Queries.

Last Updated June 11, 2019

Brent Ozar

Development

Over and over again, I run into applications that don’t parameterize their queries, and as a result: Compilations/sec is nearly as high as Batch Requests/sec CPU is high due to all those compilations Plans rarely last for more than a few hours in the cache Monitoring tools that track resource-intensive queries are useless because every…

Now is the time to sharpen your cloud database skills. Here’s how to start.

Last Updated June 10, 2019

Brent Ozar

Microsoft Azure

Many of us DBAs have been able to put off dealing with the cloud. That time is quickly coming to an end. But when was resistance to change ever a great career strategy in a tech field? Besides, two or three or four years from now, you might not have much choice in the matter.…

What Happens to DBAs When We Move to the Cloud?

Last Updated June 9, 2019

Brent Ozar

Production Database Administration

I’m finishing up a bit of a summer tour – Techorama Belgium, SQL Saturday Dallas, SQL Saturday South Florida, and this week, SQL Intersection in Orlando – and I’ve gotten the same question from several attendees. It goes something like this: “My company hasn’t moved to the cloud yet, but at every conference session, I…

Updated Stack Overflow Public Data Set for June 2019

Last Updated June 6, 2019

Brent Ozar

Stack Overflow

The place that saves your job Taryn and the kind folks at Stack Overflow have updated their public XML data dump for June, so I’ve imported that into an updated sample database for your blogging and presenting satisfaction. You can download the 40GB torrent (magnet) and it expands to a ~350GB SQL Server 2008 database. Because…

What’s Better, CTEs or Temp Tables?

Last Updated August 1, 2020

Brent Ozar

T-SQL

I get this question a lot, so let’s set up an example with the Stack Overflow database. My query’s goal is to: Find the top 5 Locations List the users who live in those top 5 Locations, alphabetized by their DisplayName There are a LOT of ways I could write this query, but for the…

Tips for Better Presentations

Last Updated June 3, 2019

Brent Ozar

Writing and Presenting

Today’s post is for those of you who give presentations to user groups and conferences. Upload your resources before the session starts. When you say “I’ll upload the resources later,” the attendee hears you saying, “I’m winging this, I barely finished this deck 15 minutes ago, and I didn’t even have the time to upload…

Why That “DBA” Job Posting Sounds So Terrible

Last Updated June 2, 2019

Brent Ozar

Professional Development

What follows are just some of the highlights from an actual job posting. I’m not including the job description, just the requirements that an applicant has to have in order to even throw their hat in the ring: Requires Bachelor’s degree or equivalent experience. Experience running and maintaining a 24×7 production computing environment Hands-on experience…

Things SQL Server Setup Doesn’t Do – And Should

Last Updated May 30, 2019

Brent Ozar

Production Database Administration

During the setup wizard, SQL Server should ask for your email address. It should suggest that you use a distribution list for people on your team, so that someone gets the alerts when you’re out on vacation. Then, it should send these common failure alerts to you rather than making you set them up manually.…

Scalar function execution plans, SQL Server 2017

User-defined scalar functions suck – even when they don’t access data.

Last Updated May 27, 2019

Brent Ozar

T-SQL

The performance of scalar functions sucks hard. Let’s see it in action using the Stack Overflow database – any size will work. I’ll set things up first in case you want to follow along: Transact-SQL USE StackOverflow2013; GO ALTER DATABASE CURRENT SET COMPATIBILITY_LEVEL = 140; GO EXEC DropIndexes; GO EXEC sp_configure 'cost threshold', 5; EXEC…

5 Questions to Ask When You Upgrade SQL Server

Last Updated May 29, 2019

Brent Ozar

Production Database Administration

Whether you’re looking to go cutting-edge and hop on SQL Server 2019 as soon as it’s available, or whether you’re just trying to evacuate from SQL Server 2008 to anything that’s going to be supported after this summer, you’re probably doing upgrade projects. This is a good time to ask yourself 5 questions: 1. Do…

Setting MAXDOP During SQL Server 2019 Setup

Last Updated May 23, 2019

Brent Ozar

SQL Server 2019

Just a short note – in SQL Server 2019, the setup process has a new MAXDOP tab: The hyperlink about MAXDOP configuration points here. I did a few quick test installs: 4 cores gave me a MAXDOP 4 8 cores offered MAXDOP 8 12 cores offered MAXDOP 6 Historically, the 0 default meant unlimited cores.…

My classes have really sucked lately, and I apologize.

Last Updated May 22, 2019

Brent Ozar

Company News

I teach my Mastering classes in a regular rotation: Mastering Index Tuning, then Mastering Query Tuning, then Mastering Server Tuning. I go 1-2-3 like that because they build on each other, and I repeat ’em over and over through the year so people can gradually make progress. I just finished another rotation, so it’s time…