Re: Fail Fast In CTAS/CMV If Relation Already Exists To Avoid Unnecessary Rewrite, Planning Costs

On Tue, Dec 22, 2020 at 03:12:15PM +0530, Bharath Rupireddy wrote:
> On Tue, Dec 22, 2020 at 2:07 PM Michael Paquier <michael@paquier.xyz> wrote:
>> Note: I'd like to think that we could choose a better name for
>> CheckRelExistenceInCTAS().
> 
> I changed it to IsCTASRelCreationAllowed() and attached a v5 patch.
> Please let me know if this is okay.

After thinking about that, using "CTAS" while other routines in the
same area use "CreateTableAs" looks inconsistent to me.  So I have
come up with CreateTableAsRelExists() as name.

As the same time, I have looked at the git history to note 9bd27b7
where we had better not give an empty output for non-text formats.  So
I'd like to think that it makes sense to use ExplainDummyGroup() if
the relation exists with IF NOT EXISTS, keeping some consistency.

What do you think?
--
Michael