Brent Ozar breaks the bad news:
Regular expressions are a way of doing complex string searches. They can be really useful, but they have a reputation: they’re hard to write, hard to read, and they’re even harder to troubleshoot. Once you master ’em, though, they come in handy for very specific situations.
This post isn’t about their complexity, though. This post is about Azure SQL DB & SQL Server 2025’s regex performance.
Brent’s testing hurts, because I want to use regular expressions, and based on what he’s seen so far, we’re probably still better off using CLR-based regex in SQLSharp.