Super slow DT3 all of a sudden

I’m using DT3 on an iMac mid-2011 running 10.13.6.
Yes, the desktop is “old” (in Apple’s head) but DT3 has only just started doing this. Very slow, spinning beachball.

I tried to post the sample process below but it was too long and disallowed.

As there haven’t been any updates of DEVONthink for this macOS version recently and as macOS 10.13.6 is quite old too, it’s unlikely that an update is the culprit.

Maybe it’s caused by virtual memory as the computer is running out of real memory? Or there’s not enough disk space on the startup volume? And finally, did you already try File > Optimize Database?

Could you hold the Option key and choose Help > Report bug to start a support ticket?
If so, please attach the process sample file too.

Done.

I haven’t yet but will do that now. Meanwhile have sent a bug report with sample process. Thank you.