Hello all
We have a live production server which has been facing performance issues for around two weeks.
The issues are intermittent. There is no pattern regarding time of day etc. The system will run well for several hours and then poorly for several hours.
We know the offending stored procedure which is causing the issues. We have been monitoring this and can see that when the system is running slowly, that its using one execution plan. When its running well, its using a different execution plan.
Why, we cannot figure out.
Updating the statistics on the table being hit within the proc helps the performance and SQL will start to use the better execution plan. However, this only seems to last for a couple of hours and then performance will hit rock bottom again (and it will flip to using the bad execution plan).
Indexes for this system are...