Message-ID: <4E49A208.5070604@darrenduncan.net>
Date: Mon, 15 Aug 2011 15:47:36 -0700
From: Darren Duncan <darren@darrenduncan.net>
User-Agent: Thunderbird 2.0.0.24 (Macintosh/20100228)
MIME-Version: 1.0
To: David Johnston <polobo@yahoo.com>
CC: pgsql-general@postgresql.org
Subject: Re: Using Postgresql as application server
References: 
 <CAN2Y=uPjF14F5A9JXj02_vaPw4TMR0WGQid_w80xt4sC8o4qGg@mail.gmail.com>
	<4E498536.9080109@darrenduncan.net>
	<008301cc5b95$e287b120$a7971360$@yahoo.com>
In-Reply-To: <008301cc5b95$e287b120$a7971360$@yahoo.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

David Johnston wrote:
>>> I believe that it is ideal for Postgres to be computationally complete in
>>> that one *could* use it to implement a complete application.  That isn't
>>> to say one should do this as a matter of course, good to use appropriate
>>> tools for a >>job, but that it should at least be possible if one wanted
>>> to. -- Darren Duncan
> 
> So who wants to fund the effort to create the necessary infrastructure to
> display a programmer-defined user interface screen (think of the "Forms"
> module in Microsoft Access)?  Or are you expecting the end-user to open up
> PgAdmin and type "SELECT hello_world();".  I would argue that because
> PostgreSQL is able to talk with many languages that can create these "Forms"
> (or even - through extensions - a web-browser) that such functionality is NOT
> DESIREABLE and thus PostgreSQL would not ideally be "computationally
> complete" by that definition.

I mean computationally complete in that Postgres is an application-level virtual 
machine within which it is technically possible to write an emulator for any 
given computationally complete language using just stock Postgres and stock PLs, 
such that say you can just feed a self-contained script to psql and that this 
script is an application capable of doing anything.  I'm not saying that it has 
to perform well but just be possible.

I certainly don't expect any interface-related higher level libraries from this 
effort, but the foundation should be there so users can create their own just by 
writing an installable Postgres extension consisting of PL procedures etc that 
don't need a C compiler.

I believe we basically have all the foundation already, with maybe procedures 
executable outside transactions being the last major part.

-- Darren Duncan