I blocked internet access on my Azure SQL Server VM with an outbound rule and started seeing PREEMPTIVE_HTTP_EVENT_WAIT. Here is one possible cause of this wait.
SQL SERVER – DBCC CHECKDB Waiting for PREEMPTIVE_OS_DEVICEIOCONTROL
A weekly DBCC CHECKDB job was stopped by a terminator job, but its SPID stayed, waiting on PREEMPTIVE_OS_DEVICEIOCONTROL. Here are ways to handle that situation.
Decoding wait_resource: From a KEY or PAGE Lock to the Table
Decode wait_resource for blocked requests, map KEY and PAGE locks to objects, and keep undocumented row-hash checks on test copies.
SQL SERVER – Many BACKGROUND Threads with Command VDI_CLIENT_WORKER
Seeing many BACKGROUND threads with command VDI_CLIENT_WORKER? Here is what the VDI_CLIENT_WORKER and VDI_CLIENT_OTHER wait types mean.
Wait Stats Collection Script for Current SQL Server Versions
A wait stats collection script saves snapshots of sys.dm_os_wait_stats into a table, so you can compare two snapshots instead of reading totals since the last restart. This post builds the tables and a snapshot procedure, creates a small load, and reports the change with a category for each wait. It also covers idle waits, restarts and retention.
SQL SERVER – Get Wait Stats Related to Specific Session ID With sys.dm_exec_session_wait_stats
From SQL Server 2016, sys.dm_exec_session_wait_stats shows wait stats for a specific session ID. Here is how to use it, and why it fails on older versions.
SQL SERVER – 3 Different Usage of DBCC SQLPERF
DBCC SQLPERF can report log usage or reset cumulative wait and latch statistics. I separate reporting from resetting the baseline.