SQL Server’s Query Store can accumulate hundreds or even thousands of queries over time. When troubleshooting a specific performance issue or investigating a particular query, you’ll probably want to search the captured data to find what you’re looking for.
DBMS
Database Management Systems
How to Check Query Store Status and Configuration in SQL Server
SQL Server’s Query Store operates independently on each database and can be in different states depending on its configuration and current storage usage. Checking the status helps you verify that Query Store is working as expected and identify any issues that might prevent data collection.
Using Subqueries with SQL Server’s DATEDIFF() Function
While SQL Server’s DATEDIFF() function is relatively straightforward when you’re comparing two known dates, it becomes more flexible when the dates you compare are sourced directly from your tables. Instead of hardcoding dates, you can embed subqueries directly into the DATEDIFF() function to dynamically retrieve the dates you need.
This approach can be especially useful when you’re working with aggregate functions like MIN() and MAX(), or when you need to pull specific dates based on certain conditions. The subqueries execute first, return their date values, and DATEDIFF() uses those results to perform the calculation.
PIVOT vs GROUP BY in SQL Server
If you’re new to SQL or just starting to explore data transformation techniques, you might be confused about when to use PIVOT versus GROUP BY. They may seem similar at first. After all, both aggregate data, both can summarize information, and both produce condensed result sets. But they serve fundamentally different purposes and produce very different output structures.
Understanding the distinction between these two operations will help you write more effective queries. GROUP BY aggregates data vertically, keeping your results in a row-based format. PIVOT transforms data horizontally, turning row values into column headers. Let’s break down exactly what each does and when you’d use one over the other.
SQL Server SUBSTRING(): A Complete Guide to Extracting Strings
The SUBSTRING() function in SQL Server lets you pull out specific portions of a string. Whether you’re cleaning data, formatting output, or parsing complex text fields, this function is one you’ll use constantly.
If you’ve ever needed to extract an area code from a phone number, grab the domain from an email address, or parse product codes into their component parts, SUBSTRING() is your go-to tool. It’s pretty straightforward, and once you understand how it works, you’ll find yourself using it all the time.
Installing the Netflix Sample Database in SQL Server
The Netflix sample database is a sample database that can be used for learning and practicing SQL. It uses data from the Netflix Engagement Report and the Netflix Global Top 10 weekly list.
This guide covers the installation process and gets you running queries quickly. For more background on what this database is and why it’s useful for learning, see my introduction to the Netflix sample database.
Fix Error 3234 “Logical file is not part of database” When Restoring a Database in SQL Server
If you’re getting error 3234 that reads something like “Logical file ‘AdventureWorksLT_Data’ is not part of database ‘AdventureWorksLT2025’. Use RESTORE FILELISTONLY to list the logical file names.“, you’re referencing the wrong logical file names when restoring a database.
This issue can happen when you try to map the logical file names to a new location, but you get those logical file names wrong.
Fortunately there’s an easy fix. It involves looking up the actual logical file names, then modifying your RESTORE DATABASE statement accordingly.
How to Get the Netflix Sample Database for SQLite
The Netflix sample database is a learning database based on public data from Netflix’s Engagement Report and Global Top 10 lists. This guide walks you through installing it on SQLite.
For more background on this database and why it’s useful for learning SQL, check out my introduction to the Netflix sample database.
How to Install Oracle AI Database 26ai on a Mac (Using Docker)
Oracle Database 26ai has officially landed. As of January 27, 2026, Oracle finally flipped the switch on the General Availability (GA) for the Linux x86-64 version, bringing the “Enterprise Edition” to data centers everywhere. This marks a major turning point in Oracle’s recent rebranding saga, where the anticipated “23ai” was bumped up to 26ai to signal its role as the long-term support (LTS) foundation for the AI era.
Oracle Database has been a powerhouse in enterprise environments for decades, and the new “AI” branding reflects their recent addition of AI-powered features like vector search.
How to Exclude Specific Queries from Query Store in SQL Server
SQL Server’s Query Store captures all queries by default (when using QUERY_CAPTURE_MODE = ALL) or resource-intensive queries (when using AUTO). However, you may want to exclude certain queries from being tracked. These might include monitoring queries, maintenance scripts, or queries from specific applications that add noise to your performance data.
SQL Server doesn’t provide a built-in mechanism to exclude specific queries from Query Store by query text or pattern. But you can achieve similar results through several approaches.