To: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
cc: Thom Brown <thombrown@gmail.com>, Joseph Conway <mail@joeconway.com>,
	Dave Page <dpage@pgadmin.org>, Steve Atkins <steve@blighty.com>,
	pgsql-docs <pgsql-docs@postgresql.org>
Subject: Re: Railroad diagrams, a-la sqlite 
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Comments: In-reply-to Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
	message dated "Sat, 17 Jul 2010 23:42:53 +0300"
Date: Sat, 17 Jul 2010 17:04:18 -0400
Message-ID: <13866.1279400658@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> On 17/07/10 23:36, Thom Brown wrote:
>> On 17 July 2010 21:30, Joseph Conway<mail@joeconway.com>  wrote:
>>> Oracle SELECT:
>>> http://download.oracle.com/docs/cd/B14117_01/server.101/b10759/statements_10002.htm

>> Yeah, that kinda chaotic.  Looks like a sadistic puzzle from the
>> Krypton Factor. :S

> Mind you, that syntax is genuinely complex. It would look chaotic using 
> the text representation we currently use as well.

Well, our own SELECT syntax isn't exactly short:
http://developer.postgresql.org/pgdocs/postgres/sql-select.html

The problem I personally see with railroad diagrams is that there's
so much whitespace in 'em.  Our current SELECT syntax diagram fits on
a page, more or less, but it would span multiple pages in railroad form.
That doesn't make for a leap forward in comprehensibility IMO.

			regards, tom lane