Execution-Plan

Tag: execution-plan

How to See Rowcounts and Execution Time for In-Flight Queries in SQL Server

How to See Rowcounts and Execution Time for In-Flight Queries in SQL Server

I frequently need to see rowcounts and execution time for queries while they’re running. Maybe I’m troubleshooting a slow query that’s still executing, or I want to understand which operators are causing the slowdown before the query completes.

Last week at the PASS Summit I learned some little nuances about how this works that I’d missed.

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Fixing OPTIMIZATION REPLAY FAILED in Query Store: When Plan Forcing Breaks in SQL Server 2022+

Fixing OPTIMIZATION REPLAY FAILED in Query Store: When Plan Forcing Breaks in SQL Server 2022+

Forcing plans with Query Store can be a powerful toolβ€” until it mysteriously fails. In real production systems, plan forcing sometimes just… doesn’t work. One common culprit is the cryptic OPTIMIZATION_REPLAY_FAILED error.

If you’re hitting OPTIMIZATION_REPLAY_FAILED, try re-forcing the plan using @disable_optimized_plan_forcing=1.

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100 Things I Hate About Views: Undeclared Data Types in Columns

100 Things I Hate About Views: Undeclared Data Types in Columns

Views let you do dumb things by accident in SQL Server. Then they make you have to think way too hard to fix them.

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Finally, a SQL Server Monitoring System That Leverages Query Store

Finally, a SQL Server Monitoring System That Leverages Query Store

I’ve spent a bit of time with Microsoft’s new database watcher tool for Azure SQL recently.

There are a lot of things I like about database watcher– which is currently in preview and which refuses to Capitalize Its Name– but it does one big thing that I really, really like: it collects data from Query Store. You can access that Query Store data from built-in database watcher dashboards, query it using KQL, or (something something) in Microsoft Fabric if you’ve got money to burn on your monitoring data.

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Query Store Size Based Cleanup Causes Performance Problems - How to Avoid It

Query Store Size Based Cleanup Causes Performance Problems - How to Avoid It

I’m a huge fan of SQL Server’s Query Store feature. Query Store collects query execution plans and aggregate query performance metrics, including wait stats. Having Query Store enabled makes troubleshooting performance issues such as bad parameter sniffing, much, much easier. Because Query Store is integrated into SQL Server itself, it also can catch query plans in a lightweight way that an external monitoring system will often miss.

When performance matters, it’s important to ensure that you’re managing Query Store so that Query Store cleanup does not run during high volume times. Query Store cleanup could slow your workload down significantly.

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You Will Not Find Long Compilers Who Time Out in Query Store

You Will Not Find Long Compilers Who Time Out in Query Store

Last November, a puzzle was really bothering me. Some queries from an application were timing out frequently after running for 30 seconds, but they were halfway invisible in the SQL Server.

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