Re: drop if exists

Alvaro Herrera wrote:

>Andrew Dunstan wrote:
>
>
>>From time to time the suggestion crops up of allowing a DROP IF EXISTS
>>... syntax. This seems not unreasonable, and I just spent a few minutes
>>looking at what might be involved.
>>
>>
>
>What about "CREATE IF NOT EXISTS" (CINE)? If we support DROP IF EXISTS
>(DIE), is the other one going to be supported too?
>
>

Maybe. But I am not sure they need to be done together.

>How does this play with schemas? I assume DIE drops the table in any
>schema in the search path. What if there's more than one; drop the
>first one?
>

Yes. Just like now. My idea was that at the point where it currently
errors out because the object exists, we would instead simply fall
through and take no action.

>CINE creates the schema in the first schema in the path,
>just like CREATE.
>
>
>Also, DIE does not need to lock the table afterwards because it won't
>exist, but CINE needs to keep a lock until transaction commit.
>
>

Right. That's one reason I thought of starting with the DIE case ;-)

cheers

andrew