Every Scooby-Doo episode has one thing in common — there’s always a fake ghost. Sometimes, that “ghost” is really just a guy in a mask trying to scare everyone with smoke machines and spooky sounds. In the SQL Server world, this ghost appears as the canned-query consultant. You’ve seen them. They roll in with a big name and an even bigger slide deck. They click “Run All,” hand you a 200-page report filled with screenshots and DMV outputs, and vanish into the night. They didn’t solve your mystery; they just dumped a list of clues in your lap. Or worse, you hired a big-name consulting firm, which brought on a…
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One thing I’ve always loved about the Scooby-Doo cartoon is that he never solved a mystery alone. Scooby and Shaggy could sniff out a clue between snacks, but it always took the rest of the Mystery Inc. gang to crack the mystery. Velma helped with her smarts, Fred with the traps, and Daphne with spotting the overlooked details—all of them used their skills to actually catch the villain. And sometimes, they even brought in special guests, such as Batman, the Harlem Globetrotters, or Don Knotts, to help tackle the really tricky cases. Performance tuning in SQL Server works the same way. The Tunnel Vision Trap When you’re buried in a…
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Over the years, I’ll admit, SQL Server has come a long way in making life easier for database administrators and with each version it keeps getting better and better. The installation process bakes in more best practices than ever, default settings are smarter, and cloud offerings like Azure SQL and managed instances take a lot of the heavy lifting off our plates. Backups, high availability, patching—all of these are more streamlined than they used to be. It’s tempting to think this means DBAs don’t need to know the “nuts and bolts” or “how things work under the hood” anymore. But here’s the problem: I am seeing a real gap in…
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Quick Tip Remove CONVERT/CAST from your WHERE clauses and JOINS when comparing to variables of different data types. Set their data types to match your table definitions before using them as a filter. Optimizing your queries this way will greatly reduce the amount of CPU time, reads, and I/O generated in your queries and allow your code to take better advantage of indexes. Example We are going to create a very simple stored procedure called ConvertExample. In this procedure we will see two things. One, the first procedure we create will declare two variables as VARCHAR( MAX) data types, then in the WHERE clause it will convert a table column…
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I regularly deliver a presentation called “Mastering TempDB”. I wrote it based on what I wish I knew about TempDB “growing up” in my career as a SQL Server DBA. It really is a breakdown of what TempDB is, how it is used, what problems actually occur within it, and how to best configure it. With advice from my colleagues, I have decided to break that down into this article to educate you. What is TempDB? TempDB is a global resource used by everyone and everything inside SQL Server. Think of it as a dumping ground for anything that doesn’t fit in memory. It is always database_id number two in…
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Does your server look like this? Many of us have inherited a SQL Server instance that has all SQL Services installed. Someone, maybe even you, went through the SQL Server installation process using GUI and checked every option available to them, then just clicked Next, Next, Next and then Install. If this is your environment, please take a moment to evaluate and decide which of these services that are required. From a performance tuning perspective, it is important to only run the services that you need. Each of these services can consume resources on your server. Sharing resources reduces what youe SQL Server Engine, SQL Server (MSSQLSERVER) or named instance…
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Bob Pusateri (B|T) tweeted a quote image that really struck a chord with me and elicited a strong reaction from myself. It got me thinking I need to write a blog on this, so here we go. Many times, over the years I’ve had conversations with people in which they have said things like below. “I can’t learn anything new because my work won’t send me to training” “I can’t learn about xyz because my boss or coworkers won’t sit down with me to show me how” “I don’t have time to learn anything new” “We’ll never go to the cloud, so I don’t need to know that” “I’m too busy…
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Indexes can be incredibly beneficial to your database performance; however, they do come with a cost—indexes both consume storage space and affect insert performance. Therefore, it is important as part of your index maintenance procedures that you periodically check to see if your indexes are being used. Many times, indexes are created in the belief they are needed but in fact they are never used. You can reduce that IO overhead on inserts when you remove unnecessary indexes. How Do You Find Them? Glenn Berry (B|T) has a fantastic script as part of his diagnostic scripts (link) that helps identify index utilization. In his diagnostic scripts it is listed as…
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One thing I learned while working as a database administrator over 17 years is the importance of teamwork across departments. Many times, we have to rely on network and SAN administrator to make changes to their environments in order to make SQL Server run more efficiently. There are times where the storage and network create bottlenecks for SQL server and after doing all the possible tuning you can do with your code and configuration you must turn to them for modifications to their hardware. Knowing how to effectively work with other departments without placing blame is crucial. As most do, we take our work personally. After all it’s your hard…
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Ever look back at old work and wonder what was I thinking when I did that? Or even better you mock and get disgusted over some code you stumble upon and then realize you wrote it? Today is one of those days. Lucky for me one of my clients is a company I used to work for. It’s awesome to be able to go back and work in an environment you are familiar with. However, with that, you realize when you worked there you made some decisions or wrote some code that you now shake your head at. On the other hand, it’s a really great way to see how…
