Re: Finer Extension dependencies

Alvaro Herrera <alvherre@commandprompt.com> writes:
> Why do features have OIDs?  Is this for pg_depend entries?  If so, would
> it work to have pg_depend entries point to extensions instead?

Yes, for pg_depend, no I don't know how to make that work with pointing
to the extensions directly, because the whole point here is to be able
to depend on a feature rather than the whole extension.

Use cases:

 - depend on a feature f that appeared in version y of the extension
   (bugfix, new capability)

 - deprecate a feature: alter extension update removes a feature, you
   want to know that the dependent extensions need processing (cascade
   to remove them in the operation, or update them before hand, etc)
   (still manual operation though)

I don't see how to handle those cases with a direct dependency on the
extension rather than one of its features.

Regards,
--
Dimitri Fontaine
http://2ndQuadrant.fr     PostgreSQL : Expertise, Formation et Support