MSSQLTips.com’s Post

SQL Server Concurrency Issues with Parallel Query Plans by Mehdi Ghapanvari >>> https://lnkd.in/ebwfH6e5 Parallelism enables SQL Server to execute queries across multiple CPU cores simultaneously. The query optimizer determines whether to execute a query in parallel or not based on cost. When a query is complex and contains expensive operators (such as sorts, aggregations, etc.) and processes many rows, it is more likely to result in a parallel plan than a simple query that processes a few rows.

A database that was "functioning." but slowing down each week. No incidents. No downtime. simply increasing latency. Typical circumstances: • The execution time of queries is gradually increasing. • An increase in CPU usage • A daily increase in the system's load Nothing important. Yet. This is the beginning of many production problems. What we discovered: • Ineffective query patterns • High-load tables lacking indexes • Increasing data volume without optimisation What we carried out: • The most costly queries were optimised. • Indexes were added without any downtime • decreased the database's needless load Outcome: There was no need for scaling infrastructure; queries became predictable once more; the system managed peak load without strain. The majority of performance issues don't call for additional resources. They need 𝗯𝗲𝘁𝘁𝗲𝗿 𝗱𝗮𝘁𝗮𝗯𝗮𝘀𝗲 𝗱𝗲𝘀𝗶𝗴𝗻. #Databases #PostgreSQL #performance #DevOps #MySQL #ClickHouse #MariaDB #MSSQL

🔐 Escalation in SQL Server 📈🔼🔴 Simple Query - But sudden explode in Production❓ It might be Lock Escalation. 🔎 What is Lock Escalation? In Microsoft SQL Server, when a query acquires too many row/page locks, the engine may automatically convert them into a table-level lock to reduce memory overhead. 👉 Small locks ➜ One big lock 👉 More blocking ➜ Less concurrency 🎯 Why Does It Happen? SQL Server escalates locks when: A statement acquires ~5000+ locks on a single object. The system is under memory pressure Large UPDATE/DELETE operations run in one transaction. 💡 Simple Example BEGIN TRAN; UPDATE Orders SET Status = 'Processed' WHERE OrderDate < '2023-01-01'; -- 100,000 rows affected -- Initially row locks -- Then escalated to TABLE LOCK COMMIT; 🔴 Result? Other sessions trying to SELECT from Orders may get blocked. Even small queries must wait. 🧠 Why It’s Dangerous in Production ➡ Causes sudden blocking chains ➡ Impacts OLTP systems heavily ➡ Can freeze high-concurrency apps ➡ Hard to detect unless monitoring locks 🛠 How to Prevent It ✅ Break large operations into batches WHILE 1=1 BEGIN UPDATE TOP (1000) Orders SET Status = 'Processed' WHERE OrderDate < '2023-01-01'; IF @@ROWCOUNT = 0 BREAK; END ✔ Create proper indexes (reduce rows touched) ✔ Keep transactions short ✔ Monitor using: 👉SELECT * FROM sys.dm_tran_locks; ✅ If Slow queries is not the reason, it might be lock escalation causing blocking storms. 💬 Have you ever faced a production outage because of lock escalation? #SQLServer #DatabasePerformance #SQLTips #LinkedInLearning #TechCareers #InterviewTips

Understanding SQL Server + CLR Integration — A Powerful Architecture!   Ever wondered how SQL Server can run .NET code inside the database engine? That’s where SQL CLR (Common Language Runtime) comes into play.   This architecture shows how SQL queries move through the Query Processor, interact with CLR modules (Stored Procedures, UDFs, Triggers, UDAs), and are hosted via the .NET CLR Hosting Module — all while maintaining different security levels:   ✅ SAFE – Access only within the database ⚠️ EXTERNAL_ACCESS – Files, Registry & Network 🚨 UNSAFE – Native DLLs & COM components   Why it matters? ✔ Enables complex business logic inside SQL Server ✔ Improves performance by reducing data round-trips ✔ Allows reuse of .NET libraries ✔ Offers flexible security control   For developers and DB professionals, SQL CLR opens doors to building smarter, faster, and more powerful database solutions.   Keep learning. Keep building. 🚀   #SQLServer #SQLCLR #DotNet #DatabaseArchitecture #SoftwareEngineering #BackendDevelopment #DataEngineering #TechLearning #DeveloperCommunity #MicrosoftSQL #CodingLife #DailyTech #LinkedInDaily

🚨 “The database is slow.” That’s all the information you get. No logs. No context. Just pressure. Most people: ➡️ Open AWR ➡️ Start guessing ➡️ Waste hours I don’t. I run **one query** first 👇 ``` SELECT event, total_waits, time_waited FROM v$system_event ORDER BY time_waited DESC FETCH FIRST 5 ROWS ONLY; ``` In less than 5 seconds, I know exactly where to look. 💡 Because performance tuning starts with one question: 👉 *Where is the database spending time?* --- ### 🔍 What this instantly tells me: ✅ I/O waits → Storage or SQL issue ✅ CPU pressure → Bad execution plans ✅ Latch/mutex → Concurrency problem ✅ Network waits → Application issue ✅ Locks → Blocking sessions No guessing. No blind troubleshooting. --- ### ⚡ Why this matters Most performance issues come from: * Inefficient SQL * Resource bottlenecks (CPU / I/O) * Poor application design If you don’t identify the bottleneck first, you’re just shooting in the dark. ### 🧠 My rule as a DBA: 👉 “Never troubleshoot performance without knowing where time is going.” This one query has saved me **hours during production issues.** --- If you’re an Oracle DBA and not using this approach yet… Start today. --- #OracleDBA #PerformanceTuning #OracleDatabase #DBA #SQL #DatabasePerformance #TechTips #LearningInPublic

I previously wrote about how the underlying technology for Fabric mirroring changed with SQL Server 2025. In this blog post, we will look at how to monitor this process, both in SQL Server and in Fabric.

For any of my folks out there using SQL 2025 and mirroring into Fabric, Meagan Longoria explains this process very well.

At both FABCON and SQLCON 2026, a clear and deliberate message for SQL Server professionals was delivered: SQL Server is not being replaced; it is being elevated. #SQLServer2025 #AzureSQL #Fabric

Well done here, John Deardurff. Microsoft SQL is here to stay and better than ever. And myriad entry points to Microsoft SQL and Microsoft Fabric exist depending on your data estate, use cases, and roadmap. Watched my good friend, Bob Ward, describe his goal with the DP-800 exam on SQL AI at SQL Saturday ATL, which is to include DBAs, SQL Developers, .NET folks, Front End guys, and even UX people. However you need to infuse your data with AI, IQ, or ML, the SQL Server 2025 database engine does it. And with the same code base in SQL 2025, Azure SQL, Fabric SQL, and Hyperscale (now supporting 128TB, and 192vCores, and 150 MiB throughput !!!!), there will never be a better time to get started. Unify Your Data! #FABCONSQLCON26 #MicosoftSQL #MicrosoftPartner

This was a great summary from John Deardurff on how SQL Server is not being replaced — it’s being elevated. As highlighted in the blog, the next phase of SQL modernization isn’t about abandoning SQL Server; it’s about extending it intelligently. A strong reminder that evolution in tech doesn’t mean replacement — it means building on what already works. #SQLServer2025 #AzureSQL #Fabric #SQLcon #FABCon