SQL Server 2025 Query Performance Tuning, 7th Edition Troubleshoot and Optimize Query Performance (Grant Fritchey)（Z-Library）

【One-Line Pitch】 A practical, end-to-end guide to making T-SQL queries fast on SQL Server 2025, covering both the enduring fundamentals (statistics, indexes, execution plans) and the new automation features. Best for developers and DBAs who own query performance and need to find, understand, and eliminate bottlenecks. 【Book Arc】 - **Opening (~0%–20%)**: Establishes why query performance matters and how SQL Server decides what to do with your query — the performance-tuning mindset and the diagnostic groundwork before touching indexes or code. - **Early (~20%–40%)**: Core fundamentals of data distribution and statistics, including cardinality estimation and parameter sniffing — the root causes behind most "the plan went bad" problems. - **Middle (~40%–60%)**: Index analysis and design plus query design best practices, aimed at preventing performance problems before they occur rather than reacting to them. - **Late (~60%–80%)**: Execution plan management and control via Query Store, plus automated performance tuning and automatic execution plan correction — turning manual firefighting into managed, repeatable process. - **Ending (~80%–100%)**: Advanced and specialized territory: extended events for deeper insight, memory-optimized OLTP tables and procedures, and how SQL Server 2025's AI-assisted automation changes the tuning workflow. 【Key Takeaways】 - **Statistics and data distribution drive plan quality** (Early): Cardinality estimation and parameter sniffing explain why the same query can be fast for one parameter value and disastrous for another — understand this before blaming the query text. - **Index design is a preventive discipline, not a rescue operation** (Middle): Analyzing and designing indexes against real workload patterns stops many performance problems from ever appearing. - **Query design and indexing go together** (Middle): Best practices for writing T-SQL and for structuring indexes reinforce each other; tuning one while ignoring the other leaves gains on the table. - **Query Store gives you control over execution plans** (Late): Managing and controlling plans through Query Store is the mechanism that makes plan regressions visible and fixable rather than mysterious. - **Automation is now part of the tuner's toolkit** (Late): Automated performance tuning and automatic execution plan correction reduce the manual burden of catching and reverting bad plans. - **Extended events provide the diagnostic depth** (Ending): They are the route to observing what the server is actually doing when surface-level metrics aren't enough. - **Memory-optimized OLTP is a distinct performance path** (Ending): Memory-optimized tables and procedures address workloads where conventional disk-based structures are the limiting factor. - **SQL Server 2025 pushes tuning toward AI-assisted automation** (Ending): AI integration for automatic tuning is presented as the headline shift in this edition, making the platform "more powerful and automatable than ever." 【Reading Tips】 - Read the fundamentals (statistics, cardinality, parameter sniffing) slowly and with a real workload open in front of you — these chapters are the diagnostic vocabulary for everything later. - Treat the index and query-design chapters as a working checklist: apply them to one slow query in your own environment as you go, rather than reading passively. - If you already manage plans manually, deep-read the Query Store and automated-tuning material — that is where this edition's practical leverage is concentrated. - Skim the memory-optimized OLTP material unless you actually run such workloads; note it exists and return when relevant. - Keep the extended events content as a reference section to revisit when you need to investigate a specific problem. 【Coverage Limits】 The source excerpts consist only of the book's front matter and description; they do not cover specific chapter titles, code examples, benchmark figures, or detailed technical procedures. This guide therefore maps the book's stated scope and progression rather than its internal chapter structure.