SQL Server Performance Office Hours Episode 80 - No Sleep Till Portugal
In this video, I discuss some interesting SQL Server questions from the office hours queue, including why blocking chains sometimes disappear when raising 'max degree of parallelism', and what plan operators might signal something is wrong in a query. I also dive into why sorts can suddenly consume more memory as data grows, and explore the nuances of tuning around terrible cardinality estimates versus rewriting queries. The heat in Paris was unbearable, causing my recording to disconnect at the end, but I managed to get through it and hope you found the answers helpful! Stay tuned for tomorrow's final video from Paris before we head to sunny Portugal next week-fingers crossed the weather improves there. CHAPTERS 00:00:00 - Introduction 00:02:30 - Office Hours Queue 00:04:45 - Blocking Chains and Max Stop 00:06:15 - Forced Plan in Query Store 00:08:07 - Terrible Cardinality Estimates ━━━━━━━━━━━━━━━━━━━━━━━━━━ 🕵️♂️ 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