Re: CREATE IF NOT EXISTS INDEX

On 2014-09-30 16:03:01 -0700, Josh Berkus wrote:
> On 09/30/2014 03:53 PM, Andres Freund wrote:
> > On 2014-09-30 18:47:24 -0400, Tom Lane wrote:
> >> Josh Berkus <josh(at)agliodbs(dot)com> writes:
> >>> On 09/30/2014 02:43 PM, Tom Lane wrote:
> >>>> =?UTF-8?Q?Fabr=C3=ADzio_de_Royes_Mello?= <fabriziomello(at)gmail(dot)com> writes:
> >>>>> What's your thoughts about we implement IF NOT EXISTS for CREATE INDEX?
> >>
> >>>> It's got the same semantic problems as every other variant of CINE.
> >>
> >>> I do think it should be name-based.
> >>
> >> Name-based, eh? Don't you recall that in modern practice, people
> >> generally don't specify names for indexes at all? They've usually
> >> got system-generated names, which doesn't seem like a very cool thing
> >> to have scripts depending on.
> >
> > Good point. I think it's fair enough to only allow CINE on named
> > indexes.
>
> On the other hand, the way we form system-generated names is predicable,
> so I think it would be perfectly OK to include them. Desirable, in fact.

It's not really that predicable. Think about expression indexes. They
also don't contain information about opclasses et all.

Seems like pit of hairy semantics.

> Not that I'm a fan of omitting the name ...

Me neither.

Greetings,

Andres Freund

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Andres Freund http://www.2ndQuadrant.com/
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