On Fri, Jan 15, 2021 at 9:10 AM Thomas Kellerer <shammat@gmx.net> wrote:
Maybe there are many "idle in transaction" sessions that prevent autovacuum from properly analyzing those tables. Or maybe for some unknown reason autovacuum was turned off. Or maybe they receive a lot of bulk loads which would require a manual analyze.
"hundreds of millions of rows"
Also of note that the default autovacuum settings for scale factor of 10-20% for vacuum & analyze behavior may need to be lowered for such a table. OP has chimed in that they believe it is being vacuumed/analyzed often enough, but if data is primarily or onnly maintained by bulk load, it would seem like autovacuum/analyze wouldn't be a factor anyway.