How Poor Cardinality Estimates Can Lead To Worse Blocking And Deadlocking In SQL Server скачать в хорошем качестве

How Poor Cardinality Estimates Can Lead To Worse Blocking And Deadlocking In SQL Server

In this video, I delve into how poor cardinality estimates can exacerbate locking situations in SQL Server, particularly focusing on the impact of bad estimates during updates and queries. I walk through a practical example using an index on the 'post' table to illustrate how SQL Server's cardinality estimation can lead to excessive locking, even when a more efficient index is available. By sharing this real-world scenario, I aim to highlight the importance of optimizing queries and indexes to minimize lock contention and improve overall database performance. CHAPTERS 00:00:00 - Introduction 00:02:15 - Index on Post Table 00:03:48 - Key Locks Explanation 00:06:12 - Index Usage Issue 00:09:01 - Parallel Distribution Streams 00:12:11 - Local Variables and Option Recompile 00:14:55 - Cardinality Estimator Discussion 00:17:00 - Conclusion ━━━━━━━━━━━━━━━━━━━━━━━━━━ 📚 TRAINING & COURSES ━━━━━━━━━━━━━━━━━━━━━━━━━━ Get AI-Ready With Erik https://training.erikdarling.com/get-... SQL Server Performance Engineering Course https://training.erikdarling.com/sql-... Learn T-SQL with Erik https://training.erikdarling.com/lear... Everything Bundle: https://training.erikdarling.com/?cou... ━━━━━━━━━━━━━━━━━━━━━━━━━━ 🛠️ CONSULTING & SERVICES ━━━━━━━━━━━━━━━━━━━━━━━━━━ Need SQL Server performance help? https://training.erikdarling.com/sqlc... ━━━━━━━━━━━━━━━━━━━━━━━━━━ 💬 CONNECT ━━━━━━━━━━━━━━━━━━━━━━━━━━ Ask questions at Office Hours https://erikdarling.com/officehours/ Become a channel member    / @erikdarlingdata   ━━━━━━━━━━━━━━━━━━━━━━━━━━