Re: Doc update proposal for the note on log_statement in the runtime config for logging page

The doc fragment you shared is explaining to customers that basic syntax checks are done before postgres gets to logging the transaction.

I don't think that is the same as clearly explaining to users statement logging happens before execution.

At least for me, as a user and reader of the docs but not someone familiar with the code, the docs didn't make it clear to me how statement logging corresponded to query execution.

Do you think there's room to document something like

"Statements are logged before they are executed. It's not guaranteed that logged statements have been successfully executed."

I'd be happy to submit and iterate on a pull request if you do.

I'd also like to understand what happens if there are errors writing the log - like the disk where the log directory is configured being full.

My understanding is the following. ereport (https://github.com/postgres/postgres/blob/71c0921b649d7a800eb2d6f93539890eaa14d979/src/include/utils/elog.h#L163) will end up calling errfinish and errfinish will call EmitErrorReport (https://github.com/postgres/postgres/blob/master/src/backend/utils/error/elog.c#L543) which will call send_message_to_server_log (https://github.com/postgres/postgres/blob/71c0921b649d7a800eb2d6f93539890eaa14d979/src/backend/utils/error/elog.c#L1733) and that will call write_syslogger_file (https://github.com/postgres/postgres/blob/71c0921b649d7a800eb2d6f93539890eaa14d979/src/backend/utils/error/elog.c#L3443C2-L3443C16).

write_syslogger_file looks like it handles errors by logging to stderr but not raising an error condition that would cancel the transaction (https://github.com/postgres/postgres/blob/71c0921b649d7a800eb2d6f93539890eaa14d979/src/backend/postmaster/syslogger.c#L1126)

Do I understand correctly or am I on the wrong codepath?