Mehedi's Earth

I was reviewing my index rebuild and recreate activities. Some index rebuilding tasks are scheduled once or twice a week. I followed the best practices for the activities. However, it was not yielding expected performance gain. So, wondering what could be going wrong! Are there any hidden issues hindering the performance? I kept searching for potential clues in my favourite SQL Server gurus writing and compiled the hidden facts. Let's share my findings with you. [More]

When it comes to SQL Server performance tuning, few settings spark as much debate as MAXDOP—Maximum Degree of Parallelism. This small but powerful configuration controls how many processors SQL Server can use to execute a single query in parallel. While parallelism can speed up queries, it can also lead to unexpected issues like CPU pressure, query blocking, or inconsistent performance across workloads.

In this article, we will explore what MAXDOP really does, why it matters, and how to configure it wisely to strike the right balance between speed and stability in your SQL Server environment. [More]

As a DBA your job is to keep an eye on your SQL Server's performance, health, and potential issues. Though SQL Server has some built-in tools and commands, but you will not get any consolidate view or resolution from them. With your tight budget, most of the time you cannot afford the hefty pricey commercial monitoring tools. Fortunately DBADash, a free, open-source monitoring tool designed by David Wiseman to help DBAs track SQL Server metrics efficiently without breaking the budget.

Whether you are managing a single server or an entire fleet, DBADash offers insightful dashboards, historical data collection, and alerting features that empower you to proactively maintain your database environment. In this article, we will explore what DBADash offers, how it works, and why it is worth considering for both personal projects and production environments. [More]

Let's have a little fun today. SQL Server stores data in MDF file which is a binary file. We will open a MDF file and search for any content. Let's start. [More]

In Part-1 we discussed, about the basic concepts of wait stat and in Part-2 we checked how to find out blocked queries, analysis of historical data, CPU pressure and primary resource waits. In this final part, you will see the common wait types, and check how to create baseline for wait stat. Let's deep drive! [More]

In part-1, we explored the basics of SQL Server Wait Statistics—what they are, how they work, and how to gauge. Now it is time to put that knowledge into action. In this part, you are going to use wait stats as a powerful tool to diagnose performance bottlenecks and guide your tuning efforts.

Think of wait stats as your server’s way of telling you where it is struggling—whether it is waiting on disk I/O, locking issues, or just CPU pressure. By learning to read these signals, you will be able to focus your optimization efforts where they matter most and keep your SQL Server running smoothly. [More]

When SQL Server slows down, it is not always easy to figure out why. That is where Wait Statistics come into play — they act like a performance stethoscope, helping DBAs listen to what SQL Server is waiting on. Every query, every process, leaves behind clues in the form of waits. By understanding these waits, you can diagnose bottlenecks, uncover hidden issues, and fine-tune your server for peak performance.

In this series, I will tell you some relevant concepts, show you how to read them, and help you decide what actions to take — so you are not just guessing anymore. [More]

When you rebuild an index in SQL Server, it might seem like a simple one-click operation—but behind the scenes, a lot is happening to ensure data integrity and performance. From acquiring locks to versioning scans and index swapping, SQL Server carefully orchestrates the entire process without disrupting your workload. Here goes the basic operations that SQL Server performs to rebuilds an index. [More]

When it comes to query performance tuning in SQL Server, key lookups are often the silent culprits that slow things down. This seemingly small operation can become expensive when repeated over thousands—or millions—of rows. In this article, we will break down what a key lookup is, why it happens, and how you can eliminate it with smarter indexing strategies. By addressing key lookups, you can significantly reduce I/O and boost query speed. So grab your execution plan and let’s uncover the hidden costs! [More]

In today's data-driven world, performance is everything—especially when working with large volumes of data. Traditional row-based indexes can struggle to keep up with modern analytics workloads. That’s where Columnstore Indexes come in. Designed for high-performance querying on massive datasets, Columnstore Indexes reshape the way SQL Server handles storage and retrieval, particularly for OLAP-style reporting and data warehousing.

In my last Columnstore Index article, I discussed about some concepts of Columnstore Index. In this write-up, we will go deeper. [More]