Category: Wait Types

⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: ASYNC_NETWORK_IO Wait TypeRelated pillar: Performance & Troubleshooting XE_BUFFERMGR_ALLPROCESSED_EVENT is recorded on a background thread while Extended Events session buffers are flushed to their targets, waiting for the “all buffers processed” signal. Flush-everything moments happen at session stops, target-state queries, and checkpoint-like…

⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: ASYNC_NETWORK_IO Wait TypeRelated pillar: Performance & Troubleshooting XE_DISPATCHER_WAIT is recorded by the background dispatcher threads that serve Extended Events asynchronous targets, while they wait for filled event buffers to process. Events accumulate in session buffers; when a buffer is ready (full,…

⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: ASYNC_NETWORK_IO Wait TypeRelated pillar: Performance & Troubleshooting XE_FILE_TARGET_TVF is recorded while a thread performs operations for a query reading event data from an Extended Events file target via sys.fn_xe_file_target_read_file, the function behind most XE analysis queries, including reading system_health files. It…

⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: ASYNC_NETWORK_IO Wait TypeRelated pillar: Performance & Troubleshooting XE_LIVE_TARGET_TVF is recorded while a thread services a query that pulls data from an Extended Events live data stream, most commonly the “Watch Live Data” viewer in SSMS. The live target streams events to…

⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: ASYNC_NETWORK_IO Wait TypeRelated pillar: Performance & Troubleshooting XE_TIMER_EVENT is recorded by a thread waiting for an Extended Events dispatch timer to expire. Event sessions with asynchronous targets buffer events in memory and hand them to the target either when a buffer…

⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: LCK_M_X, LCK_M_S, and LCK_M_U Wait TypesRelated pillar: Performance & Troubleshooting DEADLOCK_ENUM_MUTEX is recorded when the background deadlock monitor and the sys.dm_os_waiting_tasks DMV synchronise so that SQL Server never runs multiple deadlock searches at once. Computing blocking_session_id for the DMV’s output walks…

⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: IO_COMPLETION Wait TypeRelated pillar: Performance & Troubleshooting FT_MASTER_MERGE is recorded when a thread participating in a full-text master merge waits for the other participating threads to finish. A master merge happens when ALTER FULLTEXT CATALOG … REORGANIZE consolidates the many small…

⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: SOS_SCHEDULER_YIELD Wait TypeRelated pillar: Performance & Troubleshooting The cryptography-related preemptive waits track Windows crypto API calls, and this page covers the family: PREEMPTIVE_OS_BCRYPTIMPORTKEY, CRYPTACQUIRECONTEXT, CRYPTIMPORTKEY, CRYPTOPS, NCRYPTIMPORTKEY, VERIFYSIGNATURE, and VERIFYTRUST. Their customers are the engine’s encryption features: TDE key operations, backup…

⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: SOS_SCHEDULER_YIELD Wait TypeRelated pillar: Performance & Troubleshooting PWAIT_ALL_COMPONENTS_INITIALIZED appears to be a startup gate: background tasks (the SQLOS resource monitor among them, judging from its call stacks) waiting during SQL Server startup for the engine components they depend on to finish…