Re: Extensions, patch v16

On Dec 9, 2010, at 12:34 PM, Dimitri Fontaine wrote:

> - add support for 'relocatable' boolean property in the control file,
>   as discussed on list
>
>   this controls what happens at create extension time, by doing a
>   relocation of the extension objects when the extension is relocatable
>   and the asked schema isn't the first of the search_path (you can't
>   relocate an object to a schema where it already is)
>
>   when the extension is not relocatable, the mechanism used is the
>   @extschema@ replacement in the script so that the user still has a
>   say, but at create time only

This still isn't ideal, but I think it's a big improvement. Thanks.

> - nothing is done for the psql commands \dx and \dx+, here's an idea:
>
>   \dx lists only installed extensions
>   \dx+ <extension> lists the objects, calling pg_extension_objects()
>   \dX lists available extensions (and installed too)

+1 I think that's much more like existing psql commands.

> - we still depend on extension authors providing a control file. Do we
>   want to spend some efforts on trying to get rid of this file? I know
>   David desperately want to, but that's at the cost of making it much
>   harder to manage more than one extension in a single directory, for
>   once, and the Makefile mechanisms to make than happen (include a rule
>   depending on the presence of some variables, keep track of it for the
>   cleaning, etc) doesn't seem to me to worth it.

I don't think it makes it any harder to manage multiple extension in a single directory because one can create the
controlfile explicitly (or perhaps rely on .control.in for that), just as they do now. Everyone else can do less work. 

So:

* If $extension.control.in exists, use that
* If it doesn't, generate $extension.control from the Makefile variables
* Always remove $extension.control in the `clean` targets

Best,

David