> 2019-04-11 19:39:44.450844500 tuples: 19150 removed, 2725811 remain, 465 are dead but not yet removable
What Jeff said. This vacuum spent a lot of time, only to remove miserly
19k tuples, but 2.7M dead tuples remained ... probably because you have
long-running transactions preventing vacuum from removing them. Maybe
that was pg_dump.
Wouldn't "dead but not yet removable" be high if there were long running transactions holding onto old row versions?