SQL Window Functions Series: LAG() and LEAD()

Dive deep into the powerful SQL window functions, LAG() and LEAD(). Explore their intricacies, discover real-world examples, and avoid common pitfalls.

Plansplaining, part 20. SQL Graph (part 1)

Welcome to part twenty of the plansplaining series. It has been a long time since I last wrote a plansplaining post, partly because of my health, but also for a large part because I was out of ideas. But recently I decided to dig a bit deeper into a feature that was released in SQL Server 2017 and that I had so far not played with: SQL Graph.

Don’t use DISTINCT as a “join-fixer”

I’ve quietly resolved performance issues by re-writing slow queries to avoid DISTINCT. Often, the DISTINCT is there only to serve as a “join-fixer,” and I can explain what that means using an example.

Improve Query Performance when SQL Server Ignores Nonclustered Index

In this article, we look at why SQL Server may not use a non-clustered index over the clustered index and what you can do to improve performance.

Explore Natively Compiled SQL Server Stored Procedure Execution Plans

In this article, we look at execution plans and performance of a natively compiled stored procedure versus a traditional stored procedure.

Get the Most Current Row From a Detail Table

This article compares the performance of finding the most recent row in a child table for updates, looking at four possible solutions.

How to Avoid N+1 Queries: Comprehensive Guide and Python Code Examples

This article describes the N+1 problem that we often find when developers use row by row solutions for querying related data in a database.

The Complexity of Metrics

We need to monitor our servers, but individual metrics have more complexity than just setting simple limits for their readings.

Query Tuning, Why Bother?

Today Grant wonders why we spend so much time trying to learn about query tuning.

The Plan Cache Plan