Just the number of physical index and table pages written by actual checkpoint operations?
Is there any I/O optimization; e.g., predictive writes prior to a final checkpoint?
Does DiskWrite include anything else?
Physical temporary file pages?
asked 19 Jan '16, 10:46
There is only two places in SQLA that the DiskWrite database counter is incremented. They are:
So the counter does not include any writes to any auxiliary files such as unload, xp_write_file, etc (nor output... but this is done by the dbisql[c] client!)
Regarding your question "Is there any I/O optimization?". Yes, prior to a checkpoint a pass over the cache is made to flush dirty pages before the database is locked (from connections) to do the actual checkpoint.