| The wait type IO_COMPLETION is ranked #21 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. One common wait type in SQL Server is the IO_COMPLETION wait type. This wait type occurs when a query is waiting for input/output (I/O) operations to complete. I/O operations are the processes by which data is read from or written to storage devices, such as hard drives or solid-state drives. When a query encounters an IO_COMPLETION wait, it means that the query is waiting for I/O operations to complete before it can continue. This wait type can occur when multiple queries are performing I/O operations simultaneously, or when a single query is performing a large number of I/O operations. To minimize the occurrence of IO_COMPLETION waits, it is important to ensure that I/O operations are performed efficiently. This can be achieved by properly indexing tables to reduce the amount of data that needs to be read from or written to storage, and by using fast and reliable storage devices. In summary, the IO_COMPLETION wait type in SQL Server occurs when a query is waiting for input/output (I/O) operations to complete. This wait type can be minimized by properly indexing tables and using fast and reliable storage devices. Applies toSee AlsoAll Wait Types |  |