Occurs while waiting for I/O operations to complete. This wait type generally represents non-data page I/Os. Data page I/O completion waits appear as PAGEIOLATCH_* waits.
This is a general wait state for synchronous I/Os related to:
- reading transaction logs
- reading and writing sort data during a sort spill
- reading allocation bitmaps for start-up/restore actions
How to reduce this wait
As with general I/O performance issues look for:
- changes in execution plans
- client side software releases
- stuck processes
If this article doesn't have the information you need you can try searching online. Remember, you can contribute suggestions to this page.
- Google Search for sqlserver - IO_COMPLETION
- Ecosia Search for sqlserver - IO_COMPLETION
- Bing Search for sqlserver - IO_COMPLETION