Re: COPY Transform support

Decibel! wrote:
> On Apr 3, 2008, at 4:51 PM, Andrew Dunstan wrote:
>> Several years ago Bruce and I discussed the then theoretical use of a 
>> SELECT query as the source for COPY TO, and we agreed that the sane 
>> analog would be to have an INSERT query as the target of COPY FROM.
>>
>> This idea seems to take that rather further. If doable I think it 
>> would be cool, as long as people don't try using it as an alternative 
>> storage engine. I can just imagine people creating views over such 
>> SELECT statements ...
>
>
> Why not? There's certainly cases where doing just that could be very 
> valuable. Storing older information that you're less likely to query 
> comes to mind... in those cases you're going to be seqscanning anyway, 
> so being able to read off a compact on-disk form is likely to be a win 
> performance-wise. It could certainly be a win storage-wise.
>
> If someone wants to look at syntax options, I'm pretty certain that 
> Oracle supports this. IIRC you actually create what appears to the 
> database to be a real table, except for restrictions on what you can 
> actually do with it (for example, IIRC it's read-only).
>

You're serious aren't you?

Quite apart from any other reason why not, this would be a horrid hack 
and is just the sort of "feature" we rightly eschew, IMNSHO. COPY is 
designed as a bulk load/unload facility. It's fragile enough in that role.

If we really want to support an alternative storage engine then we 
should tackle that front on and not via a back door like this.

cheers

andrew