From PostgreSQL wiki
PostreSQL Extension System Wishlist
The following items were brought up as useful improvements to the PostgreSQL extension code:
- Planner hooks for extensions
- A way to add trigger-extension dependencies, e.g. ALTER EXTENSION ... ADD TRIGGER ...
- A way to specify how extension-owned objects' ownership changes (or doesn't) when the table to which they're attached changes ownership
- Whitelist listing extensions which non-superusers may install at their discretion
- Multiple versions of an extension installed simultaneously
- Ability to grant permission to install an extension instead of permissions flowing through to the actions taken by the extension code.
- Object metadata (key/value pairs on db objects)
- Some way to remove code duplication between full and upgrade sql scripts e.g. by changing the install process to use the latest full sql and then apply incremental sql scripts to get to a particular version.
- Better automation of upgrading & testing
- Inline extensions allowing additional files to be installed without server access
- Make check w/o install
- Global extension dir/listing (not sure what this means now...)
- Build farm that could e.g. check installability of all modules on pgxn
- Package auto build (not sure what this means now...)
- A list of extensions "blessed" by the PostgreSQL community as stable, well-supported, etc. and some way to determine if an extension makes it onto this list.