The signal wait time inside your total wait time tells you something important. Total wait = resource wait signal wait. Resource wait: time waiting for the actual resource (lock, I/O, memory). Signal wait: time sitting in the runnable queue after the resource is granted, waiting for a scheduler. High signal wait as a percentage of total wait means CPU pressure — not necessarily an I/O or lock problem. SELECT wait_type, wait_time_ms, signal_wait_time_ms, 100.0 * signal_wait_time_ms / NULLIF(wait_time_ms, 0) AS signal_pct FROM sys.dm_os_wait_stats WHERE wait_type NOT IN ( -- exclude idle waits 'SLEEP_TASK','BROKER_TO_FLUSH','SQLTRACE_BUFFER_FLUSH' ) ORDER BY wait_time_ms DESC; #SQLServer #WaitStats #Performance #CPU

Every slow query leaves clues. Sometimes it is blocking. Sometimes it is high CPU. Sometimes it is wait stats quietly waving from the corner. Sometimes it is a poor execution plan doing “creative work” in production. 🙂 That is why performance tuning is not just about fixing one query. It is about following the evidence, reading the plan, asking better questions, and understanding what SQL Server is really trying to do. I am excited to present: SQL Server Performance Survival Kit for the AI Era May 11 Workshop • Techorama Belgium In this workshop, we will explore practical ways to identify performance problems, analyze execution plans, understand wait stats, and use AI-driven insights without losing the human judgment that real production systems still need. Follow the clues. Fix the performance. See you at Techorama Belgium. #SQLServer #PerformanceTuning #QueryTuning #ExecutionPlans #WaitStats #AI #DatabasePerformance #Techorama #PinalDave

Feeling grateful to share that I am fully booked for the first week of May with multiple SQL Server Performance Tuning engagements! 🚀 April has been one of the busiest and most rewarding months in recent memory. A quick technical overview: 🔹 117 queries tuned and optimized — Common patterns included excessive nested loops, missing SARGability, and redundant implicit conversions. In several cases, query execution times dropped by 85–95%, directly improving application responsiveness and reducing overall CPU pressure. 🔹 32 major server-level and database-level configuration changes — including fine-tuning settings like MAXDOP, Cost Threshold for Parallelism, Memory Grant Threshold for Serial Queries, TempDB optimizations (multiple files, trace flags), and adjusting the Query Store capture mode for better performance insights. 🔹 Index optimization: 74 non-used or low-impact indexes dropped after a careful review using sys.dm_db_index_usage_stats. 18 highly targeted indexes created, focusing on key lookup eliminations, covering indexes for critical queries, and filtered indexes for selective access patterns. In most environments, reducing index overhead led to noticeable gains in DML operations and better buffer cache hit ratios. 🔹 Statistics updates (both full and sampled) were performed across mission-critical tables, ensuring better cardinality estimations and helping the optimizer generate better execution plans. 🔹 Significant work was done around parameter sniffing issues — including use of OPTIMIZE FOR UNKNOWN, query hints, and forced parameterization strategies where needed. 🔹 Blocking and Deadlock Resolution: Identified and resolved multiple blocking chains through deadlock graph analysis and redesign of transaction scopes. Implemented lock escalation prevention strategies and optimized isolation levels where appropriate. 🔹 Wait Statistics Analysis: Addressed high CXPACKET, PAGEIOLATCH_XX, and WRITELOG waits across several production environments. The beauty of SQL Server tuning lies in the details. Every environment is different — but the goal is always the same: faster queries, stable systems, and happy users. If you’re looking to schedule a SQL Server performance review or tuning session, mid-May is the perfect window to plan ahead — or we can also target the first week of June depending on your timeline. Thank you to all the wonderful clients who trusted me with their most critical systems. It’s a privilege to be part of your performance journey. 🧡 #SQLServer #PerformanceTuning #DatabaseOptimization #QueryTuning #IndexTuning #WaitStats #DeadlockResolution #SQLServerConsulting

Deep SQL Query Optimization with SQL Grease Learn how to conduct deep SQL #queryoptimization with SQL Grease with the Enterprise dashboard, historical data, troubleshooting #SQLServer #WaitStats, capturing #anomalies, and intelligent notifications. mssqltips.com/sqlservertip/6…

Our favorite blog posts of the week More info: buff.ly/3UnTVAg #ladataplatform #dbatools #trustworthy #waitstats #datatrasfer #sqlserver #extendedevents

Quem aí nunca viu uma query demorando e com o Wait ASYNC Network IO? Vídeo do meu curso que liberei no canal da Power Tuning no Youtube: youtube.com/watch?v=b8WdcUNy… #tuning #performance #sqlserver #protheus #totvs #waitstats #async #soupowertuning #microsoft #goldpartner

I created a new github repo to help collect and monitor waitstats over time: michaeljswart.com/2021/01/co…

My first post as Chief Scientist at @SentryOne : Why Wait Stats Alone Are Not Enough sqlperformance.com/2020/01/s… #sqlserver #sqlblog #waitstats #querystore #azuresqldb

Interesting that this title is held by three women! Hello ladies, great to be in your company ❤️

But she's so funny! She should get a couple of points for her humor alone. 🤣

So...those outfits are some kind of weird, sick propaganda organs, therefor the odious badge is weird, sick propaganda

evidence?

Thanks

Thanks for the f I appreciate it

Me: Why is my dev DB so damn slow? Waitstats: PREEMPTIVE_XE_DISPATCHER:99.7% Me: Hmm... maybe it's that XE session I created called "locks"

SQL Server - Capture the Wait Stats to table for analysis wp.me/p1xCpR-ul #sqlserver #waitstats #VarinderSandhuBlog

@evdlaar talking about waitstats on #sqlsat505 #SQLSatBelgium

@danarel @ryanjbell @waitstats Murray wasn't making fun of trans gendered. His target was those who insist the topic be a sacred cow.

@danarel Why do people walk away from authoritarian religion to return to authorities like this? @roblanderos @waitstats

@danarel @waitstats They were humoring the SJW attitude towards the issue, not the trans people themselves.