SQL Server Performance Office Hours Episode 77 Paris is nice again

In this video, I dive into some common SQL Server performance issues and offer practical solutions. Starting off, we explore why SQL Server might suddenly change join strategies for the same query text-often due to factors like recompilation or changes in statistics. I also discuss when it's time to consider redesigning your database schema versus continuing with tuning efforts. Moving on, I address scenarios where SQL Server seems to pause everything for a few seconds before recovering, touching on potential causes such as locking and blocking, resource contention, and query memory grants. Lastly, I tackle the question of whether to prioritize average duration or P95 performance metrics in Query Store, highlighting the importance of verifying data sources and considering other factors that might impact query performance beyond just memory grants. Enjoy the view of Paris while you watch! CHAPTERS 00:00:00 - Introduction 00:01:25 - Query Plan Changes Explained 00:04:07 - Redesign vs Tuning 00:06:39 - Performance Queues and Delays 00:08:58 - Query Store Analysis ━━━━━━━━━━━━━━━━━━━━━━━━━━ 🕵️‍♂️ FREE SQL SERVER MONITORING & Plan Analysis ━━━━━━━━━━━━━━━━━━━━━━━━━━ https://github.com/erikdarlingdata/PerformanceMonitor https://github.com/erikdarlingdata/PerformanceStudio https://plans.erikdarling.com/ ━━━━━━━━━━━━━━━━━━━━━━━━━━ 📚 TRAINING & COURSES ━━━━━━━━━━━━━━━━━━━━━━━━━━ Get AI-Ready With Erik https://training.erikdarling.com/get-ai-ready-with-erik?coupon=AIREADY SQL Server Performance Engineering Course https://training.erikdarling.com/sql-server-performance-engineering?coupon=ENGINEERING Learn T-SQL with Erik https://training.erikdarling.com/learn-t-sql-with-erik?coupon=ADVANCEDTSQL Everything Bundle: https://training.erikdarling.com/?coupon=SPRINGCLEANING ━━━━━━━━━━━━━━━━━━━━━━━━━━ 🛠️ CONSULTING & SERVICES ━━━━━━━━━━━━━━━━━━━━━━━━━━ Need SQL Server performance help? https://training.erikdarling.com/sqlconsulting ━━━━━━━━━━━━━━━━━━━━━━━━━━ 💬 CONNECT ━━━━━━━━━━━━━━━━━━━━━━━━━━ Ask questions at Office Hours https://erikdarling.com/officehours/ Become a channel member https://www.youtube.com/@ErikDarlingData/join