remote query debugging was: Plugins redux

Tom Lane wrote:
> The other, probably more controversial bit of functionality is that there
> needs to be a way to cause a backend to load a PL plugin shared library
> without any cooperation from the connected client application.  For
> interactive use of a PL debugger it might be sufficient to tell people to
> do "LOAD 'plpgsql_debugger'" before running their function-to-be-tested,
> but if you're trying to debug some behavior that only manifests in a large
> complicated application, it may be impractical to get the application to
> issue such a command.  
A similar issue applies to plain SQL that's not touching any PL: In the
past, I encountered numerous situations where I'd have liked to take a
peek at the current application's queries (on MSSQL, this can be done
with SQL Profiler), but not have constant statement logging. IMHO it
would be a good idea if

- debugging could be turned on and off on-the-fly, e.g. to skip the app
startup phase. Thus I question the statement "GUC variable is sufficient"
- the mechnism would cover plain SQL too.

Regards,
Andreas