My SQL Server 2016 had been presenting problems certain days, all process since the morning begins to run slowly than normally. Sometimes updating statistics works, sometimes not and had to reboot service. In query plan, when things go wrong with the "main" query, it shows a high negative value, after things start to work well, the query plan show normal values.
There is something else thing I could do and somebody knows why sometimes update stats doesn't work?
Thanks in advance