Re: [postgis-devel] About EXTENSION from UNPACKAGED on PostgreSQL 13

Greetings,

* Darafei "Komяpa" Praliaskouski (me(at)komzpa(dot)net) wrote:
> PostGIS 2.5 had raster and vector blended together in single extension.
> In PostGIS 3, they were split out into postgis and postgis_raster extensions.

For my 2c, at least, I still don't really get why that split was done.

> To upgrade, there is now postgis_extensions_upgrade() function, that
> unpackages the raster part out of postgis extensions, upgrades it, and
> packages raster functions back into postgis_raster by utilizing FROM
> UNPACKAGED.
> Removal of FROM UNPACKAGED breaks PostGIS 2.5 -> 3.0 upgrade path, and
> we haven't yet found a proper replacement since such removal wasn't
> something we were expecting.

I agree that there probably isn't a very good path to allow an extension
to be split up like that without having to drop some things. An
alternative would have been to *not* split up postgis, but rather to
have a postgis_raster and a postgis_vector. Adding in support for other
ways to migrate a function from one extension to another would make
sense too.

Thanks,

Stephen