Search Results for “first responder kit”

Writing Diagnostic Queries is Hard Because SQL Server Still Has (Tiny) Bugs.

Last Updated November 19, 2019

When I first got started working with SQL Server, I assumed it was flawless because it came in a sealed box from a ginormous corporation. I figured they’d tested every edge case, and that there was no way things were gonna go sideways. These days, even though I read CU KB articles and giggle about…

4.3b Final Lab: Logging sp_BlitzCache to a Table

Last Updated September 14, 2021

Brent Ozar Unlimited Team

Oops! In the last module, while tuning a query, I accidentally cleared the plan cache with DBCC FREEPROCCACHE. Normally, that would be a huge problem for performance tuning – but thankfully, I’m logging sp_BlitzFirst and sp_BlitzCache to tables every 15 minutes in the lab. I show you how to jump back in time and grab…

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Which Version of SQL Server Should You Use?

Last Updated October 18, 2023

Brent Ozar

SQL Server, SQL Server 2016, SQL Server 2017, SQL Server 2019

150

Wait! Before you install that next SQL Server, hold up. Are you sure you’re using the right version? I know, management wants you to stay on an older build, and the vendor says they’ll only support older versions, but now’s your chance to make your case for a newer version – and I’m gonna help…

Upcoming Free Training Webcasts

Last Updated January 16, 2019

Brent Ozar

Videos

Hey, wanna learn about SQL Server for free? Feb 7 – PASS Data Expert Series: PASS is taking the top-rated Summit 2018 recordings and replaying them live, for free, on a webcast. I’ll be in the chat room too, taking your questions. Register here, and the lineup includes: SSMS & T-SQL Tricks with Bob Pusateri…

SQL Server Perfmon counters that are still interesting in 2019

Last Updated January 16, 2019

Brent Ozar

Monitoring

“Page Life Expectancy? That belongs in a museum!“ (Cross-posted from the PASS Blog.) Years ago, my first go-to tool for performance tuning was Performance Monitor: it was available everywhere, worked in all versions, and gave me a lot of useful information without paying for a monitoring tool. Since then, I’ve moved on – wait stats…

Fast Food Code

Last Updated January 2, 2019

Erik Darling

SQL Server

Cheap and Easy We’ve all done it. We all know what and where it is, because we’ve probably left a comment for ourselves to go fix it later. It wasn’t me, I swear to myself. Either it was expedient, it seemed to work locally, it was fast on a small amount of data, or we…

Query Store And Cruel Defaults

Last Updated December 19, 2018

Erik Darling

Execution Plans, Query Store (QDS)

Gosh Darn Now, look, it’s no secret that I think Query Store is cool. Heck, I went and wrote sp_BlitzQueryStore so you can examine it similarly to how sp_BlitzCache looks at the plan cache. For a variety of reasons, though, we run into people who can’t or won’t turn it on, or who had to turn…

Sniffed Nulls and Magic Numbers

Last Updated May 26, 2020

Erik Darling

Parameter Sniffing, SQL Server

I Sniff Your Milkshake Building off of A Simple Stored Procedure Pattern To Avoid, I wanted to talk about a similar one that I see quite often that is not nearly as clever as one would imagine. I goes something like this: If this variable is passed in as NULL, substitute it with something else.…

Adventures In Foreign Keys 3: Why Cascading Deletes Perform Slowly

Last Updated December 29, 2021

Erik Darling

Execution Plans, Foreign Keys, Locking, Blocking, and Isolation Levels

Legendreary In the last post, I looked at some issues with implementing foreign keys with cascading actions. Namely that, well, it fell apart pretty quickly just trying to set up. I didn’t even get to the point where I wanted to test all those relationships. But there’s an even worse surprise waiting for you if…

The Curse of Cursor Options

Last Updated November 2, 2018

Erik Darling

Execution Plans

Red Skies At Night I know it’s hard to believe, but I still see a lot of people using cursors when they shouldn’t. Other times, there’s some scary dungeon part of the code that someone wrote eons ago that no one wants to go anywhere near to fix. Sometimes there’s a decent reason, something like:…

You read reviews before you buy training, right?

Last Updated October 23, 2018

Brent Ozar

Company News

Confession time: I love buying stuff. It’s not so much the buying as it is the comparing. I go to The Wirecutter, I read every review on Amazon, and I make little Excel spreadsheets to show differences between products. So what about when you buy database training? Do you read the reviews? If you’ve been…

Queries With Poor Cardinality Estimated or Skewed Parallelism

Last Updated October 21, 2018

Erik Darling

Dun Goofed If you’re here, you hit an issue where SQL Server made a bad guess at how many rows it’d have to deal with in a query. This doesn’t always indicate a killer performance issue, but it does warrant investigation. This can happen for a lot of reasons, including parameter sniffing, implicit conversion, non-SARGable…

Index Tuning Week: Fixing Nonaligned Indexes On Partitioned Tables

Last Updated September 28, 2018

Erik Darling

SQL Server

Unquam Oblite This post will not change your life, but it will help me remember something. When you decide to partition a table to take advantage of data management features, because IT IS NOT A PERFORMANCE FEATURE, or you have an existing partitioned table that takes advantage of data management features, because IT IS NOT…

Can Forced Parameterization Go Wrong?

Last Updated May 26, 2020

Erik Darling

Execution Plans, Parameter Sniffing, SQL Server

App Like That If you’ve got the kind of application that sends bare-assed strings to SQL Server, you may end up with a weird choice. Brent will be sitting on one shoulder telling you to use Forced Parameterization. I’ll be on the other shoulder asking if you’ve really thought this whole thing through while you…

Building SQL ConstantCare®: You Should Probably Learn Power BI. I Did.

Last Updated September 2, 2018

Brent Ozar

SQL ConstantCare

When I was prepping for the PASS Summit last year, I wanted to unveil something awesome and free that would help you analyze your SQL Server’s performance. I ended up building the Power BI Dashboard for DBAs, an easy way for you to visualize your server’s wait stats. When we started building SQL ConstantCare®, our…

High Compilers

Last Updated August 26, 2018

Erik Darling

Bright Light City If you’re here, you most likely have a plan in your cache that uses a lot of resources to compile. By itself, this isn’t a very interesting or actionable metric, but if you add in some other stuff, you can find interesting problems. If plans like this compile or recompile frequently, you…

Wait Stats Should Be Easy By Now

Last Updated July 20, 2018

Erik Darling

Wait Stats

Why Is My Query… We’ve all started a question with a close approximation of those words. No matter how you finish that sentence, there’s some basic information that you need to collect to figure it out, like: Query plan Wait stats Other server activity Those are a good place to start. It’s easy enough to…

Do I Have A Query Problem Or An Index Problem?

Last Updated July 20, 2018

Erik Darling

SQL Server

Party Up When someone says “this query is slow”, and you can rule out contextual stuff like blocking, odd server load, or just an underpowered server, what’s the first thing you look at? There’s a lot of potential culprits, and they could be hiding in lots of different places. Pick a card, any card. After…

Is the CXCONSUMER Wait Type Harmless? Not So Fast, Tiger.

Last Updated August 9, 2020

Erik Darling

Execution Plans, SQL Server

Let’s say you’ve got a query, and the point of that query is to take your largest customer/user/whatever and compare their activity to smaller whatevers. If SQL Server doesn’t balance that work evenly across multiple threads, you can experience the CXCONSUMER and/or CXPACKET wait types. To show how SQL Server ends up waiting, let’s write…

Building SQL ConstantCare®: Analyzing Query Plans

Last Updated June 24, 2018

Erik Darling

SQL ConstantCare

XML Delenda Est Last week, I talked about how we’re going to be collecting query plans from users who opt to have us do so (and only users who opt in! No surprises, here) by leveraging code we already have written in sp_BlitzCache, and how we’re going to do the XML analysis on our end using…

Search Results for “first responder kit”

Hi! I’m Brent Ozar.