Re: foreign data wrappers

On Thu, March 24, 2011 12:49 pm, Alvaro Herrera wrote:
> Excerpts from Zheng Yang's message of jue mar 24 05:49:19 -0300 2011:
>
>> I am quite new to postgresql, but slowly picking up :) In general
>> context, storing images directly inside DBMS fields as BLOBs was not
>> considered as a good practice.
>> However, storing file directories or links may cause inconsistency. So
>> I am quite interested in how this datalink concept can be implemented!
>
> I'm not really sure how different would be handling the file linking in
> an FDW. For example, if a transaction runs that deletes a file through
> the FDW, and the transaction rolls back, how are you going to restore
> the file to life?
>
> (It sounds like you're trying to have a FDW that would present a
> directory as a table, and each file in the dir as a row. Maybe it's not
> a bad idea but it needs a lot more thought.)
>

Currently FDWs can't store anything. They are read-only.

But I don't really buy this stuff about not storing images in the
database. I've done numbers of apps that do exactly that with great
success. If the images are huge that's another matter, but for small
images it works just fine.

cheers

andrew