So these past few days I’ve noticed unusual CPU spikes that led to a really hot and loud MBP. Hella load appeared to be coming from mds_stores. It took me a while to figure out that I was actually causing that myself.
I use Spotlight a lot as a calculator since it’s always just cmd-space away from whatever I’m doing and my hands never need to leave the keyboard. Turns out, in Catalina when you invoke calculator functionality from Spotlight you send it on some crazy loop that leads to near 100% load courtesy of the mds_storage process. I was wondering if perhaps I had configured something in an odd fashion (I restrict quite heavily what Spotlight is allowed to search), but it turns out others have stumbled on this issue as well. And apparently it’s a bug in Catalina Spotlight where for some reason Spotlight has trouble parsing entries as algebraic statements to send to calculator which then leads to the excessive load.
Apple’s “Community Specialist” was apparently quite useless (offering the generic Spotlight re-indexing, SMC reset, yada yada). Looks like this will require an actual patch from Apple. Anyway, in case anybody else is noticing excessive load from mds_stores this is what might be triggering it.
Work around right now: a) immediately after calculating a result delete it so Spotlight stops trying to parse the statement, b) move to Siberia and consider hot MacBook a feature or c) get out my trusty old HP-15C and use that instead of Spotlight. Prefer RPN anyway.