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  • BACKUPIO and BACKUPBUFFER Wait Types in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related pillar: Backup & Recovery BACKUPIO and BACKUPBUFFER appear when backup operations are waiting on I/O: Microsoft’s wait types reference gives both the same one-line description (a backup task waiting for data, or for a buffer to store it), so the split above comes…

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  • DEADLOCK_ENUM_MUTEX Wait Type in SQL Server

    ⏳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 Is It a Problem? No. It is not a known contention point, and it was zero on our SQL Server 2025 lab. Get Wait Statistics does not filter it out, so…

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  • FT_MASTER_MERGE Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: IO_COMPLETION Wait TypeRelated pillar: Performance & Troubleshooting Is It a Problem? Not as contention. It follows master merges, which you schedule, and it is not a known contention point. Get Wait Statistics does not filter it out, so if it ranks,…

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  • PREEMPTIVE_OS Crypto Wait Types in SQL Server

    ⏳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 preemptive waits track Windows crypto calls, and this page covers the family: PREEMPTIVE_OS_BCRYPTIMPORTKEY, CRYPTACQUIRECONTEXT, CRYPTIMPORTKEY, CRYPTOPS, NCRYPTIMPORTKEY, VERIFYSIGNATURE and VERIFYTRUST. Microsoft lists most as internal use only, and does not list BCRYPTIMPORTKEY…

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  • PWAIT_ALL_COMPONENTS_INITIALIZED Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: SOS_SCHEDULER_YIELD Wait TypeRelated pillar: Performance & Troubleshooting Is It a Problem? No. It is not reported as a contention point, and it is commonly filtered as benign. Get Wait Statistics does not filter it out, so if it ranks, you will…

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  • PWAIT_EXTENSIBILITY_CLEANUP_TASK Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: SOS_SCHEDULER_YIELD Wait TypeRelated pillar: Performance & Troubleshooting Is It a Problem? No. It is a background timer, commonly filtered as benign, and Get Wait Statistics filters it out by default. It often shows among the top waits on SQL Server 2019…

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  • REQUEST_FOR_DEADLOCK_SEARCH Wait Type in SQL Server

    ⏳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 Is It a Problem? No. Microsoft says it is expected between deadlock detections, and lengthy total waiting time on this resource doesn’t indicate a problem. Get Wait Statistics filters it out…

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  • RESOURCE_SEMAPHORE_QUERY_COMPILE Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: RESOURCE_SEMAPHORERelated pillar: Performance & Troubleshooting ⚡RESOURCE_SEMAPHORE_QUERY_COMPILE is a query stuck before execution, waiting for a slot to keep compiling because too many memory-hungry compilations are running at once. Short bursts after a restart are normal. Sustained, it means a steady stream…

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  • WAIT_XTP_OFFLINE_CKPT_NEW_LOG Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: WRITELOG Wait TypeRelated pillar: Performance & Troubleshooting Is It a Problem? No. It is commonly filtered as benign, and Get Wait Statistics filters it out by default. It was zero on our SQL Server 2025 lab, which has no memory-optimized tables.…

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  • XE_TIMER_MUTEX Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: ASYNC_NETWORK_IO Wait TypeRelated pillar: Performance & Troubleshooting Is It a Problem? No. It is not a known contention point; it was zero on our SQL Server 2025 lab. Get Wait Statistics does not filter it out, so if it ranks, you…

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