Hi, The current logical walsender integration looks like the following:
=# INIT_LOGICAL_REPLICATION 'text'; WARNING: Initiating logical rep WARNING: reached consistent point, stopping! replication_id | consistent_point | snapshot_name | plugin ----------------+------------------+---------------+-------- id-2 | 3/CACBDF98 | 0xDEADBEEF | text (1 row) =# START_LOGICAL_REPLICATION 'id-2' 3/CACBDF98; ... So the current protocol is: INIT_LOGICAL_REPLICATION '$plugin'; returns * slot * first consistent point * snapshot id START_LOGICAL_REPLICATION '$slot' $last_received_lsn; streams changes, each wrapped in a 'w' message with (start, end) set to the same value. The content of the data is completely free-format and only depends on the output plugin. Feedback is provided from the client via the normal 'r' messages. I think thats not a bad start, but we probably can improve it a bit: INIT_LOGICAL_REPLICATION '$slot' '$plugin' ($value = $key, ...); START_LOGICAL_REPLICATION '$slot' $last_received_lsn; STOP_LOGICAL_REPLICATION '$slot'; The option to INIT_LOGICAL_REPLICATION would then get passed to the 'pg_decode_init' output plugin function (i.e. a function of that name would get dlsym()'ed using the pg infrastructure for that). Does that look good to you? Any suggestions? Greetings, Andres -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
