I have a slow performing query and to in order to tune it I'm planning to take a step-by-step approach. My query has started performing slowly on 12/8 moving forward which is when the last time three out of 7 of the statistics were updated.
The primary key statistic was updated last on 12/8 and hasn't been updated after that and another statistic on a unique (non-clustered) column was also updated on 12/8 and hasn't been updated after that. Another non-unique, non-clustered columns statistics were updated on 12/8 and haven't been updated after that either. The system statistic was updated last on 12/10.
This query I'm referring to (stored procedure) used to run from 30-40 min now to 5+ hours. I'm thinking updating the statistics might help.
My question is... is it feasible to update the statistics on these columns during production hours? Or is it typically recommended to update the statistics later on at night? I have never updated statistics before and am not familiar with how long it takes.
Thanks in advance for all replies.