As Adrian and I have said, pg_dump and pg_dumpall as backwards compatible and the recommended method for porrting data from one version
to another. You will NOT get errors if you use plain format.
I can't use plain.
And i've had errors with plain in this scenario before. Especially around sequences, that could be "OWNED BY" someone since 8.4 if i remember correctly.
But there were more things.
A new thing is ERROR: unrecognized configuration parameter "row_security" , but that doesn't reallyt do any harm.
But there's more that i don't remember, since i learned how to avoid them.