Wait Type REDO_THREAD_PENDING_WORK

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 REDO_THREAD_PENDING_WORK wait type in SQL Server is a type of wait that occurs when a task is waiting for the redo thread to catch up with the work that is being generated by the transaction log. The redo thread is a component of the SQL Server database engine that is responsible for applying changes to the database from the transaction log.

When a task performs an operation that modifies data in the database, the changes are recorded in the transaction log before they are applied to the database. The redo thread reads the changes from the transaction log and applies them to the database.

If the redo thread falls behind and cannot keep up with the rate at which changes are being generated, the REDO_THREAD_PENDING_WORK wait type will occur. This wait type indicates that a task is waiting for the redo thread to catch up before it can proceed.

This wait type can occur when the redo thread is unable to keep up with the workload, either because the workload is too high or because the redo thread is not configured optimally. A database administrator can monitor the occurrence of this wait type and take steps to optimize the redo thread, such as increasing the number of redo threads or adjusting the configuration settings.

In summary, the REDO_THREAD_PENDING_WORK wait type in SQL Server occurs when a task is waiting for the redo thread to catch up with the workload. This wait type can be a result of high workload or suboptimal configuration of the redo thread. A database administrator can monitor and optimize the redo thread to reduce the occurrence of this wait type.

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Applies to

See Also

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