Humor

Brent Ozar Unlimited Team

“No, don’t bother the DBA. It’s probably not a database problem.” “But it says right here that it worked on my machine.” “Solid state storage sure is overrated.” “Thank God for auto-shrink, really saved the day again.” “We’re not picky – you can apply updates whenever you want, whenever’s convenient.” “The VM admin said to…

Database History: The Inventor of the Data Page

December 15, 2017

Database History

Do you ever wonder about the history of the systems you rely on every day? They didn’t teach us database history in school. Instead, we got calculus and art and interpretive dance. Fat lot of good that did us, right? So from time to time, we’re taking it upon ourselves to bring you the history…

Can you prevent deletes and inserts without a WHERE clause from running?

December 14, 2017

Bad Idea Jeans, Humor

dba, development, sql server

File this under bad idea thong In the tradition of Klaus Aschenbrenner wanting to prevent people from writing SELECT * queries, I thought it might be nice to prevent people from running deletes or updates without a WHERE clause. In a vaguely scientific way. Now, I don’t really condone this. It just seemed funny at…

French makes everything sound so sexy.

October 20, 2017

Even error messages: Transact-SQL SELECT * FROM sys.messages WHERE language_id = 1036; 12 SELECT * FROM sys.messagesWHERE language_id = 1036; Produces: Talk dirty reads to me These sound better than anything I would ever write in a romantic letter: “SQL Server a détecté une corruption de mémoire matérielle dans la base de données « %1! », à l’ID…

Do Variables Exist?

October 17, 2017

I know, I know I swore I’d never talk about variables again. Then I ran into some funny business. Maybe it was quite as funny as the Temp Table Ghosts, but hey. What’s as funny as temp tables? It’s in your heaaaaaaaad If I run this, what do you think will come back? Transact-SQL IF…

Bad Idea Jeans: Finding Undocumented Trace Flags

October 4, 2017

Bad Idea Jeans

I need to start this blog post with a disclaimer: you should not be doing this. Hell, *I* should not be doing this. But when SQL Server 2017 came out Monday, I noticed a few unusual SNAPSHOT_MATERIALIZATION entries in sys.messages and a few related undocumented system objects that hinted about a new feature Microsoft hadn’t…

Answering Questions For Fun And No Profit

September 21, 2017

I love answering questions about SQL My forum of choice is dba.stackexchange.com because I find the voting and point system with badges for being a decent internet person addictive. If you like more traditional forums, SQLServerCentral.com has a lot of really smart people on it as well. When I post questions or answers, I try…

The Ghosts of Temp Tables Past

September 19, 2017

True story You may find it hard to believe, but I recently had to fix a small bug in sp_BlitzCache and sp_BlitzQueryStore. Since both stored procedures have similar functions, they also share some temp table names (mainly the ones for parsing down XML nodes to more manageable chunks). In the window where I was making…

What If Week: What Would You Look At First?

August 16, 2017

For this week’s What If series, we’re exploring what would happen if you had access to SQL Server’s source code – like if you got a job at Microsoft, signed a partner NDA, if the code leaked, or if it went open source. Today’s question is, “What would you look at first?” Brent says: I’d…

What If Week: SQL Server Code Review

August 15, 2017

Top Secret For the sake of any lawyers out there reading, I want to start by saying we do not now, nor have we ever possessed SQL Server’s source code. I wouldn’t even know what to do with it if I did — I doubt it’s written in crayon. Heck, I’m not even competent enough…

How to Drop All Your Indexes – Fast

August 11, 2017

Bad Idea Jeans, Indexing

Sometimes I need to reset stuff during performance training classes. I know some of you teach classes, too, and some of you just like doing crazy stuff. So here you go, a stored procedure to lose weight fast: DropIndexes for SQL Server 2016 & Newer Transact-SQL CREATE OR ALTER PROCEDURE dbo.DropIndexes @SchemaName NVARCHAR(255) = 'dbo',…

Live Blogging: Erik vs. PowerShell

July 29, 2017

Oh, hey, happy Saturday First, I’d like to apologize to Conor Cunningham for the blatant theft of a blog title. That’s what you get for not posting in three years (like the desert miss the rain~). Why am I here? Why am I writing PowerShell, my sworn enemy? I do it for you. I’m trying…

There’s Something Funny About Variable Assignment

June 28, 2017

dba, development, sql server

Guess who I’m going to give you three queries, and you have to guess what the output will be before you run them. Here they are: Transact-SQL DECLARE @DatabaseName NVARCHAR(256) = N'' SELECT @DatabaseName = d.name FROM sys.databases d WHERE d.name = 'master' AND compatibility_level = 130 ORDER BY d.database_id PRINT @DatabaseName SELECT @DatabaseName =…

Why Your Biggest Query Plans Don’t Show Up in Some DMVs

June 2, 2017

Bad Idea Jeans, Execution Plans

SQL Server has three ways to get execution plans from the plan cache: sys.dm_exec_query_plan – around since SQL Server 2005 sys.dm_exec_text_query_plan – added in 2005 SP2 sys.query_store_plan – new in SQL Server 2016 And there’s an important problem with the first one. To show it, let’s take one of my many bad ideas, building queries that take 12+…

Bad Idea Jeans: Multiple Index Hints

May 26, 2017

Bad Idea Jeans, T-SQL

dba, development, performance tuning, sql server

I hate that you can do this Here’s the thing: I’m mostly writing this because I didn’t know you could do it. But it’s cool, because it’ll reinforce some other concepts, and I’ll show you why you shouldn’t do it. I’m talking, of course, about index hints. To be more specific, hinting multiple indexes on…

CTEs, Views, and NOLOCK

March 29, 2017

dba, development, performance tuning, sql server

This is a post because it surprised me It might also save you some time, if you’re the kind of person who uses NOLOCK everywhere. If you are, you’re welcome. If you’re not, thank you. Funny how that works! I was looking at some code recently, and saw a CTE. No big deal. The syntax…

First Responder Kit Release: We hired Brent back because he promised to fix his code

March 21, 2017

March comes in like a 40 of Steel Reserve and leaves like your memory of the night after drinking a 40 of Steel Reserve. Get it here! sp_Blitz Improvements — #758 and #756 We made it less scary to run on Express Edition. Why? Because running Express Edition is scary enough. Coded by @Totty1973 and…

I’m just saying it’s valid T-SQL syntax, that’s all.

February 24, 2017

Bad idea #1 Bad idea #2 Bad idea #3

Stupid Things I’ve Done With SQL

November 15, 2016