For any database software, IO is so critical. The READS and the WRITES. And the amount of time it takes to get to the data – the latency factor. So in hindsight, the overall storage strategy plays such a critical role. You really want a very fast storage subsystem for your queries to go super fast. When I deal with IO metrics, latency comes on top of my mind. Simply put, latency is the time it takes for the IO request to be completed. Well, the storage custodians have many ways to calculate it and monitor it. As a SQL pro, how do you compute latency from inside SQL Server? Answer: leverage the sys.dm_io_virtual_file_stats DMV. This DMV has to two attributes – num_of_reads & io_stall_read_ms – for each data & log file in your SQL instance. So looking at the attributes, does it ring some bells? How can you compute latency now? Sounds interesting? Watch the video below.
Get new content directly in your inbox – Click here
You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code).
Hope the video was worth your time.