Hi,
I observed absurd behaviour while using pg_logical_slot_peek_changes()
and pg_logical_slot_get_changes(). Whenever any of these two functions
are called to read the changes using a decoder plugin, the following
messages are printed in the log for every single such call.
2023-03-19 16:36:06.040 IST [30099] LOG: starting logical decoding for slot "test_slot1"
2023-03-19 16:36:06.040 IST [30099] DETAIL: Streaming transactions committing after 0/851DFD8, reading WAL from 0/851DFA0.
2023-03-19 16:36:06.040 IST [30099] STATEMENT: SELECT data FROM pg_logical_slot_get_changes('test_slot1', NULL, NULL, 'format-version', '2');
2023-03-19 16:36:06.040 IST [30099] LOG: logical decoding found consistent point at 0/851DFA0
2023-03-19 16:36:06.040 IST [30099] DETAIL: There are no running transactions.
2023-03-19 16:36:06.040 IST [30099] STATEMENT: SELECT data FROM pg_logical_slot_get_changes('test_slot1', NULL, NULL, 'format-version', '2');This log is printed on every single call to peek/get functions and bloats
the server log file by a huge amount when called in the loop for reading
the changes.
IMHO, printing the message every time we create the context for
decoding a slot using pg_logical_slot_get_changes() seems over-burn.
Wondering if instead of LOG messages, should we mark these as
DEBUG1 in SnapBuildFindSnapshot() and CreateDecodingContext()
respectively? I can produce a patch for the same if we agree.
