[HACKERS] Detecting schema changes during logical replication

Hello,

I'm putting together a replication system based on logical
replication. I would like to send table information only the first
time a table is seen by the 'change_cb' callback, but of course there
could be some schema change after replication started. So I wonder: is
there any information I can find in the 'Relation' structure of the
change callback, which may suggest that there could have been a change
in the table schema, hence a new schema should be sent to the client?

Thank you very much,

-- Daniele