No the dropouts are not related to the database...its a signal issue..can be the cams, the network, the blue iris pc, blue iris...
I finally solved this problem and in the end it was simple.
I happened to notice that the last time there was any data recorded was when I last logged on. That was a fairly small file. It also seemed to me that files previous to that were also small and were timed at about the times I had logged onto this server. I hadn't made that connection before.
Remember that I said we run BI as a service? We’ve done that since first installing. When we upgraded to version 4 it seemed that all our settings were carried forward from the prior version. It turns out the check box for “run as a service” was an exception. So, all this time, when I thought we should have been recording, we were not, because that box remained unchecked.
After discovering that a couple of hours ago, and checking the box, recording now seems to be back to normal. Mystery and problem solved.