PREEMPTIVE_OS_FILEOPS SQL Server Wait Type

Wait Type PREEMPTIVE_OS_FILEOPS

The wait type PREEMPTIVE_OS_FILEOPS is ranked #85 by Stedman Solutions and Database Health Monitor.

Wait statistics, in the context of SQL Server, refer to the amount of time that a query spends waiting to access data in the database. When a client application requests data from the database, the request is placed in a queue and the client application must wait for its turn to access the data. The time that the query spends waiting is called a "wait" and is tracked by SQL Server. This information can be used to identify potential performance bottlenecks and optimize the performance of the database. Wait statistics are commonly used by database administrators to diagnose and troubleshoot performance issues in SQL Server.


The PREEMPTIVE_OS_FILEOPS wait type in SQL Server indicates that a task is waiting on a file operation performed by the operating system. This wait type typically occurs when a query is accessing data or files that are located outside of the SQL Server instance, such as on a network share or in the file system.

When a query is executed in SQL Server, it is compiled into an execution plan by the query optimizer. The execution plan specifies the sequence of operations that SQL Server will use to retrieve the requested data. If the query involves accessing data or files that are located outside of the SQL Server instance, the execution plan will include a reference to the external resource.

When the query is executed, SQL Server will send a request to the operating system to access the external resource. The PREEMPTIVE_OS_FILEOPS wait type occurs while SQL Server is waiting for the operating system to complete the file operation and return the requested data.

The presence of the PREEMPTIVE_OS_FILEOPS wait type does not necessarily indicate a problem with SQL Server. However, if this wait type is occurring frequently and for long periods of time, it could indicate that the queries being executed are accessing external resources that are slow or heavily utilized. In these cases, it may be necessary to optimize the queries or to add additional hardware resources to improve performance.

In summary, the PREEMPTIVE_OS_FILEOPS wait type in SQL Server indicates that a task is waiting on a file operation performed by the operating system. While this is a normal part of the operation of SQL Server, frequent occurrences of this wait type could indicate a potential performance issue that should be addressed.


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Applies to

Related Waits

PREEMPTIVE_COM_CREATEACCESSOR
PREEMPTIVE_COM_GETDATA
PREEMPTIVE_COM_QUERYINTERFACE
PREEMPTIVE_COM_RELEASE
PREEMPTIVE_COM_RELEASEROWS
PREEMPTIVE_COM_SEQSTRMREAD
PREEMPTIVE_COM_SETPARAMETERINFO
PREEMPTIVE_COM_SETPARAMETERPROPE
PREEMPTIVE_FILESIZEGET
PREEMPTIVE_HADR_LEASE_MECHANISM
PREEMPTIVE_OLEDB_RELEASE
PREEMPTIVE_OLEDBOPS
PREEMPTIVE_OS_AUTHENTICATIONOPS
PREEMPTIVE_OS_AUTHORIZATIONOPS
PREEMPTIVE_OS_AUTHZGETINFORMATIO
PREEMPTIVE_OS_AUTHZINITIALIZECON
PREEMPTIVE_OS_AUTHZINITIALIZERES
PREEMPTIVE_OS_BACKUPREAD
PREEMPTIVE_OS_CLOSEHANDLE
PREEMPTIVE_OS_CLUSTEROPS
PREEMPTIVE_OS_CREATEFILE
PREEMPTIVE_OS_CRYPTACQUIRECONTEX
PREEMPTIVE_OS_CRYPTIMPORTKEY
PREEMPTIVE_OS_CRYPTOPS
PREEMPTIVE_OS_DELETEFILE
PREEMPTIVE_OS_DEVICEIOCONTROL
PREEMPTIVE_OS_DEVICEOPS
PREEMPTIVE_OS_DTCOPS
PREEMPTIVE_OS_ENCRYPTMESSAGE
PREEMPTIVE_OS_FLUSHFILEBUFFERS
PREEMPTIVE_OS_GENERICOPS
PREEMPTIVE_OS_GETCOMPRESSEDFILES
PREEMPTIVE_OS_GETDISKFREESPACE
PREEMPTIVE_OS_GETFILEATTRIBUTES
PREEMPTIVE_OS_GETFINALFILEPATHBY
PREEMPTIVE_OS_GETPROCADDRESS
PREEMPTIVE_OS_LIBRARYOPS
PREEMPTIVE_OS_LOADLIBRARY
PREEMPTIVE_OS_LOGONUSER
PREEMPTIVE_OS_LOOKUPACCOUNTSID
PREEMPTIVE_OS_MOVEFILE
PREEMPTIVE_OS_NETVALIDATEPASSWOR
PREEMPTIVE_OS_PIPEOPS
PREEMPTIVE_OS_QUERYREGISTRY
PREEMPTIVE_OS_REPORTEVENT
PREEMPTIVE_OS_REVERTTOSELF
PREEMPTIVE_OS_SECURITYOPS
PREEMPTIVE_OS_SERVICEOPS
PREEMPTIVE_OS_SQLCLROPS
PREEMPTIVE_OS_VERIFYTRUST
PREEMPTIVE_OS_WAITFORSINGLEOBJEC
PREEMPTIVE_OS_WRITEFILEGATHER
PREEMPTIVE_SERVICE_CONTROL_MANAGE
PREEMPTIVE_SERVICE_CONTROL_MANGE
PREEMPTIVE_SHAREDMEM_GETDATA
PREEMPTIVE_XE_CALLBACKEXECUTE
PREEMPTIVE_XE_GETTARGETSTATE
PREEMPTIVE_XE_SESSIONCOMMIT
PREEMPTIVE_XE_TARGETFINALIZE
PREEMPTIVE_XE_TARGETINIT

See Also


All Wait Types
PREEMPTIVE_OS_FILEOPS SQL Server Wait Type