postgresql installation - PL/???

Tom Allison wrote:

This should be a dumb question:

--with-perl

I don't see that I have to do this in order to load pl/perl as a
function/trigger language option. So I should assume that this will
compile pl/perl in rather than having it available as a loadable
function. Nice for optimizations?

If you compile --without-perl you will not be able to use PL/Perl.
There will be no loadable module in that case.
It is not a question of optimization.

I'm assuming this is the case because there is no option for something
like PL/Ruby support, but Ruby is available as a loadable function.

Only if you download, compile and install PL/Ruby, which is a separate
module that is not in the PostgreSQL core distribution.
That will give you a loadable module for PL/Ruby.

Compiling and installing PL/Ruby is the equivalent of building
--with-perl (PL/Perl is included in PostgreSQL core).

And should I also be able to assume that PL/PgSQL is compiled into
postgresql?

PL/pgSQL is always built, there is no special flag to enable it.

so I don't really need to use any particular flags, with the probable
exception of --with-ssl?

Depends.
If you want only PL/pgSQL, you need no extra flags.
If you need PL/Perl, compile --with-perl.
If you want PL/Ruby, you must download, compile and install it.

Creating a procedural language in PostgreSQL involves two steps:
1) Build and install the loadable module (which is what my answers are about).
2) Run a CREATE LANGUAGE statement in the database where you want the
procedural language.

Yours,
Laurenz Albe