The advertised fix list says 2.14.1 fixes the database bloat that we’ve seen since 2.9 or so.
I had been running a workaround job twice a day:
console core:purge-old-archive-data 2015-07-01 2015-06-01 --include-year-archives
I stopped running this when I installed 2.14.1, assuming the problem had been fixed. I looked at the DB today and saw that it was back to its bad behavior (6x as many rows as with 2.9, or whatever it was; 2x as many rows as last month).
I ran the workaround and it got me back to the bad old days (triple the size of before, but not 6x).
I re-enabled the jobs.