When trying to resync an old primary to become a new standby, I have found
that pg_rewind only works occasionally. How reliable/robust is pg_rewind,
and what are its limitations? We have observed that approx half our FPIs in
the WALs are due to XLOG/FPI_FOR_HINT. The only reason we've set
wal_log_hints=on is so that we can use pg_rewind. But if pg_rewind is
unreliable, we would rather turn off wal_log_hints. Any info on the
reliability of pg_rewind and its limitations would be appreciated.
Thanks, Curt