Re: psql: Add \dL to show languages

On mån, 2011-01-17 at 07:37 +0100, Magnus Hagander wrote:
> >> which, as Magnus points out, includes non-procedural languages (SQL).
> >>
> >> I think that "list languages" could be confusing to newcomers -- the
> >> very people who might be reading through the help output of psql for
> >> the first time -- who might suppose that "languages" has something to
> >> do with the character sets supported by PostgreSQL, and might not even
> >> be aware that a variety of procedural languages can be used inside the
> >> database.
> >
> > Fair point.
>
> Yeah. Procedural langauges may strictly be wrong, but people aren't
> likely to misunderstand it.

The term "procedural" in this context originated with Oracle's PL/SQL,
which is a procedural language extension to the non-procedural SQL
language. From this came PostgreSQL's PL/pgSQL, and that naming was
then continued with PL/Tcl, at which point "PL/$X" lost its original
meaning of "procedural extension to the non-procedural language $X" and
meant more or less "handler for writing PostgreSQL functions in language
$X".

Otherwise PL/Scheme will blow your mind. :)

Think of "procedural language" as "language for writing [PostgreSQL]
procedures". As was pointed out, it's also a useful convention for
distinguishing this from other "languages", such as message
translations.