From: Tom Lane <tgl@sss.pgh.pa.us>
To: Stephen Frost <sfrost@snowman.net>
cc: Alvaro Herrera <alvherre@2ndquadrant.com>,
        Robert Haas <robertmhaas@gmail.com>, Thom Brown <thom@linux.com>,
        "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Subject: Re: Add support for restrictive RLS policies
In-reply-to: <20160908200912.GW4028@tamriel.snowman.net>
References: <20160908183544.GU4028@tamriel.snowman.net>
 <20160908192157.GA53172@alvherre.pgsql>
 <20160908200912.GW4028@tamriel.snowman.net>
Comments: In-reply-to Stephen Frost <sfrost@snowman.net>
	message dated "Thu, 08 Sep 2016 16:09:12 -0400"
Date: Thu, 08 Sep 2016 17:21:25 -0400
Message-ID: <5611.1473369685@sss.pgh.pa.us>
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org

Stephen Frost <sfrost@snowman.net> writes:
> * Alvaro Herrera (alvherre@2ndquadrant.com) wrote:
>> Can't you keep those words as Sconst or something (DefElems?) until the
>> execution phase, so that they don't need to be keywords at all?

> Seems like we could do that, though I'm not convinced that it really
> gains us all that much.  These are only unreserved keywords, of course,
> so they don't impact users the way reserved keywords (of any kind) can.
> While there may be some places where we use a string to represent a set
> of defined options, I don't believe that's typical

-1 for having to write them as string literals; but I think what Alvaro
really means is to arrange for the words to just be identifiers in the
grammar, which you strcmp against at execution.  See for example
reloption_list.  (Whether you use DefElem as the internal representation
is a minor detail, though it might help for making the parsetree
copyObject-friendly.)

vacuum_option_elem shows another way to avoid making a word into a
keyword, although to me that one is more of an antipattern; it'd be better
to leave the strcmp to execution, since there's so much other code that
does things that way.

			regards, tom lane


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