My scenario was the following. I got the following error message:
postgres=# create trusted language plpythonu;
ERROR: could not load library "C:/Program Files/PostgreSQL/lib/plpython.dll": unknown error 126
I had Python 3.1 installed and I did not know that PostgreSQL does not support this. The time it took to figure this out was around a quarter of an hour, epecially since a search for "error 126" did not yield any results.
My proposal is to somehow convert ANY error message into a url. This url should be to a WIki page where one could get help regarding the error message. In the case above the url COULD be:
postgres=# create trusted language plpythonu;
ERROR: could not load library "C:/Program Files/PostgreSQL/lib/plpython.dll": unknown error 126
Wiki help on error: http://wiki.postgresql.org/wiki/Error:_plpython.dll_error_126#8.4
The conversion method is, of course, critical and I am sure someone else has better ideas regarding this. The url could also include parts of the statement leading to the error message (in my case "plpythonu").
One really nice side effect of this that if one could count the number of page visits on each wikipage, one would get a nice estimate on which error messages cause the most trouble for the users (users would not go to the wiki to research obvious error messages). The #8.4 part of the url means that this statistic could be generated for each version of PostgreSQL.
