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Date: Fri, 12 Aug 2022 10:58:37 -0400
From: Bruce Momjian <bruce@momjian.us>
To: "David G. Johnston" <david.g.johnston@gmail.com>
Cc: frank_limpert@yahoo.com, Pg Docs <pgsql-docs@lists.postgresql.org>
Subject: Re: CREATE TABLE AS, section IF NOT EXISTS should clarify what
 happens to the data
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On Mon, Jul 18, 2022 at 03:43:03PM -0400, Bruce Momjian wrote:
> fOn Thu, Jul 14, 2022 at 06:47:19PM -0700, David G. Johnston wrote:
> > Not only is the existing table not modified, I think that the select query
> > portion of the command is never even executed.  That would seem to be useful
> > knowledge to have.
> > 
> > Maybe something like:
> > 
> > <para>
> >  Do not throw an error if a relation with the same name already exists.
> >  A notice is issued in this case.
> >  If <literal>WITH DATA</literal> is specified (the default) the execution of
> > the parsed query does not happen, leaving the existing table with its existing
> > contents.
> > </para>
> 
> I tried to go in that direction, but couldn't clearly name the
> SELECT/VALUES part of the CREATE TABLE AS query because CREATE TABLE
> AS is also a query.  I felt trying to say we ran the CREATE TABLE AS
> query but not the SELECT/VALUES of the query was just too confusing.  I
> used "simply issue a notice" as implying that nothing else happens,
> which I considered sufficient.
> > 
> > I've removed the xref to create table as there is nothing additional there of
> > material benefit - the sentence:
> 
> Okay, removed.  Updated patch attached.

Patch applied back to PG 10.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Indecision is a decision.  Inaction is an action.  Mark Batterson