I'm planning to change the error level of a specific error message. We can use emit_log_hook for this purpose but we have no reliable means to identify what a message is.
For messages without valid sqlerrcode, filename:lineno could be used to identify but lineno is too unstable. One possible and most straightforward way to solve this is defining identifiers covering all error messages but such identifiers are too hard to manage. ErrorData.message could also be used but NLS translation and placeholders prevent it from being identified by simple means like strcmp(3).
As a solution for this problem, I'd like to porpose to have an additional member in the struct ErrorData to hold a message id, that is, the format string for errmsg(). This is not best but useful enough.
It is somewhat a crude way, but the attached small patch would do.
Is there any opinions or suggestions?
First, I support the concept of message ids and any work you do in moving this forwards.
If you were to require message ids, how would this work for extensions? Many things write to the log, so this solution would rely upon 100% compliance with your new approach. I think that is unlikely to happen.
I suggest an approach that allows optionally accessing a message id by hashing the English message text. That would allow people to identify messages without relying on people labelling everything correctly, as well as writing filters that do not depend upon language.
I'm guessing this would require making the pre-translated error text available to plugins as well as translated form.
--
Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services