I have an iMac (Retina 5K, 27-inch, Late 2015) with a 4 GHz Intel Core i7 Processor and16 gigs ram and the new update was using all four cores through the whole indexing process. This does not seem normal
High CPU usage while indexing is to be expected.
in the past its only been a short time at the end
I’ve felt the same thing recently.
Previously indexing didn’t really seem to affect anything else I was doing, now it does seem to have an impact if I am trying to browse the Internet or write a document at the same time.
I haven’t tried to analyse it at all.
I haven't noticed anything unusual. My MacBook Pro (older than the OP's) did get hot with the last indexing... but there were 12 Reverse Interlinears, some datasets + the ESVSB updated!
I am now indexing a new purchase without skipping a beat, CPU cores running low... no problems.
EDIT: Spoke too soon! CPU cores at max. Perhaps there is an issue after all!
I use an app called TG Fan Control it monitors the temp of all my internal componants and ramps up the fan speed as needed. During indexing some cores hit 100c for a few seconds.
the new update was using all four cores through the whole indexing process.
It will try to index four resources at a time, so it will allocate up to 4 threads; which could well use your four cores in order to spread the load.
The last phase (merging) is disk intensive, takes about 10 min for me and uses mainly one thead.