A drop failed for Availability Group message can describe a partial removal, where SQL Server and Windows clustering no longer agree. The tests here read the HADR state, show what errors 41000 and 41081 say and prove that SET ONLINE cannot open a database that sits in RESTORING.
SQL SERVER – Installation Error: System.ArgumentNullException – Value Cannot be Null
A client automating SQL Server installs saw random failures: System.ArgumentNullException, Value cannot be null. Here is what Detail.txt showed and the cause.
SQL SERVER – How Do I Evaluate Monitoring Tools?
I evaluate monitoring tools by collection cost, historical context and usefulness in choosing a correction. Customer discussions shaped those three criteria.
Compiled Parameter Values in SQL Server: Read Them From the Cache
Compiled parameter values show which value SQL Server used when it built a cached plan. This post reads them from the plan cache with one query, then shows how the first caller shapes the plan for everyone after. It ends with the usual ways to break that link.
SQL SERVER – Reviewing Sleeping Sessions Before Terminating Any Session
An inactive or sleeping session may still be a useful pooled connection. A customer case prompted my earlier session-cleanup script.
Dirty Pages – How to List Dirty Pages From Memory in SQL Server? – Interview Question of the Week #223
Question: How to List Dirty Pages From Memory in SQL Server? Answer: I received question today during my SQL Server Performance Tuning Practical Workshop.
SQL SERVER – Error: 9642 – An error occurred in a Service Broker/Database Mirroring transport connection endpoint
Error 9642 in the ERRORLOG: an error occurred in a Service Broker/Database Mirroring transport connection endpoint. Here is what caused it for my client.