Sorry about that; I do know to do it properly and usually get it right. GMail doesn’t seem to have an option (that I can find) to leave no space at the top and put my cursor at the bottom; it nudges pretty firmly in the direction of top-posting. Thanks for the reminder.
I don't think printing a few first rows is a good idea - usually there is nothing interesting (same is PL/Perl, PL/Python, ...)
If the proposed feature can be generic, then this information should be stored somewhere in pg_language. Or we can redesign usage of prosrc and probin columns - but this can be a much more massive change.
I’m looking for a quick win. So I think that means either drop the source column entirely, or show single-line source values only and nothing or a placeholder for anything that is more than one line, unless somebody comes up with another suggestion. Originally I was thinking just to remove entirely, but I’ve seen a couple of comments suggesting that people would find it unfortunate if the source weren’t shown for internal/C functions, so now I’m leaning towards showing single-line values only.
I agree that showing the first line or couple of lines isn't likely to be very useful. The way I format my functions, the first line is always blank anyway: I write the bodies like this:
$$
BEGIN
…
END;
$$;
Even if somebody uses a different style, the first line is probably just "BEGIN" or something equally formulaic.
