Re: [HACKERS] IF (NOT) EXISTS in psql-completion

On Wed, Feb 22, 2017 at 12:38 AM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
> Now first patch is broken :(
>
> It is pretty sensitive to any changes. Isn't possible to commit first four
> patches first and separately maybe out of commitfest window?

Yeah, maybe, but we'd need a committer to take more of an interest in
this patch series.  Personally, I'm wondering why we need a series of
19 patches to add tab completion support for IF NOT EXISTS.  The
feature which is the subject of this thread arrives in patch 0017, and
a lot of the patches which come before that seem to change a lot of
stuff without actually improving much that would really benefit users.

0001 seems like a lot of churn for no real benefit that I can immediately see.
0002 is a real feature, and probably a good one, though unrelated to
the subject of this thread.  In the process, it changes many lines of
code in fairly mechanical ways; does it need to do that?
0003 is infrastructure.
0004 adds a README.  Do we really need that?  It seems to be
explaining things which are mostly fairly clear from just looking at
the code.  If we add a README, we have to update it when we change
things.  That's worthwhile if it helps people write code better, I'm
not sure if it will do that.

0005 extends 0002.
0006 prevents incorrect completions in obscure circumstances.
0007 adds some kind of tab completion for CREATE RULE; I'm fuzzy on the details.
0008 improves tab completion after EXPLAIN.
0009-0014 uses the infrastructure from 0003 to improve tab completion
for various commands.  They say they're merely simplifying tab
completion for those things, but actually they're extending it to some
obscure situations that aren't currently covered.
0015 adds completion for magic keywords like CURRENT_USER when role
commands are used.
0016 refactors tab completion for ALTER DEFAULT PRIVILEGES, possibly
improving it somehow.
0017 implements the titular feature.
0018 adds optional debugging output.
0019 improves things for CREATE OR REPLACE completion.

Phew.  That's a lot of work for relatively obscure improvements to tab
completion.  I grant that the result is probably better, but it's a
lot of code change for what we get out of it.  I'm not saying we
should reject it on that basis, but it may be the reason why nobody's
jumped in to work on getting this committed.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company