Date: Thu, 19 Sep 2019 18:47:08 +0900 (Tokyo Standard Time)
Message-Id: <20190919.184708.25203401.horikyota.ntt@gmail.com>
To: alvherre@2ndquadrant.com
Cc: a.korotkov@postgrespro.ru, andres@anarazel.de, n.gluhov@postgrespro.ru,
 thomas.munro@gmail.com, pgsql-hackers@postgresql.org, david@pgmasters.net,
 michael@paquier.xyz
Subject: Re: Psql patch to show access methods info
From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
In-Reply-To: <20190918140440.GA28323@alvherre.pgsql>
References: 
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	<20190918140440.GA28323@alvherre.pgsql>
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Hello. FWIW..

At Wed, 18 Sep 2019 11:04:40 -0300, Alvaro Herrera <alvherre@2ndquadrant.com> wrote in <20190918140440.GA28323@alvherre.pgsql>
> I think in order for this feature to be more complete "\d index" should
> show the opfamily name, also, even when it's the default one.  (Let's
> not put the opfamily when it's the default in "\d table", as we do when
> the opfamily is not default; that would lead, I think, to too much
> clutter.)
> 
> > > On the other hand, from a user perspective, what you really want to know
> > > is: what opfamilies exist for datatype T, and what operators are
> > > supported by the opfamily I have chosen?  The current patch doesn't
> > > really help you find that out.

I have thought that several times.

> I hope that in some future somebody will contribute towards this, which
> I think is more important (from users POV) than the below one:
> 
> > > I think \dAp isn't terribly informative from a user perspective.  The
> > > support procs are just an opfamily implementation detail.
> > 
> > I've expressed my opinion regarding \dAp in [1].  In my observations,
> > some advanced users can write btree/hash opclasses in pl/* languages.
> > This doesn't require knowledge of core developer.  And they may find
> > \dAp command useful.  What do you think?
> 
> I have never tried or had the need to do that.  I'll take your word for
> it, so I have no objection.
> 
> I do wonder if \? is going to end up with too much clutter, and if so do
> we need to make \? show only the most important commands and relegate
> some others to \?+ ... however, going over the existing \? I see no
> command that I would move to \?+ so \dAp would be alone there, which
> would be pretty strange.  So let's forget this angle for now; but if
> psql acquires too much "system innards" functionality then I say we
> should consider it.

Before the fact that usable slot of two-letter commands is almost
filled, my poor memory rejects to remember the commands that is
used infrequently..  ctrl-I suggests many two-or-three letter
meta commands but I can't tell what is the command I'm searching
for. \? shows too many commands as you mentioned.

If something like "\? | grep index" works, it would be helpful.

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center