comments about meeting agenda

[Regina Obe]

> > So one can build postigs, with the sfcgal dependency not installed,
> > and get a postgis extension, and then later, with the sfcgal
> > dependency installed/present, and build *just* the postgis-sfcgal
> > extension, and when both packages are installed all works as the user
> expects?
> 
> I'm not sure about *just* the postgis-sfcgal extension, I suspect not, but I
> guess we could accept a patch to allow that.
> 
> Buiding *without* the posgis-sfcgal extension should work.
> 

You can't build postgis-sfcgal without building postgis too.
It's also always assumed you want to build postgis, unless you build --without-pgconfig.
When you use that --without-pgconfig it only builds the tools shp2pgsql /shp2pgsql / raster2pgsql

The issue before which we solved is - you had a single library for example: postgis-2.5.so
And that library was used as the backend library  for both postgis  and postgis_sfcgal.

So what happened is if the first time you built with sfcgal, your postgis-2.5.so would be fatter and have all these extra dependencies dragged in cause it had all the sfcgal functions in it and had a dependency on sfcgal.

Then if you decided to build without next time then your postgis-2.5.so would not have sfcgal functions in it.

That is undesirable from a PostgreSQL policy standpoint not to mention being confusing that the functions in the same version of postgis-2.5 would be different.
Now with the postgis 3 series, all sfcgal functions are in a postgis_sfcgal-3  and postgis is in postgis-3.

There was discussion in the meeting about packaging, that since postgis and postgis_sfcgal extensions don't rely on the same lib anymore it is easier to offer them as separate products.  I didn't completely follow how that would work.

If you have a postgis_sfcgal of course you need postgis, cause postgis_sfcgal extension is dependent on postgis extension.

However if you just want postgis, you don't need to have postgis_sfcgal following along and thus wouldn't need additional dependencies required by sfcgal.

You could be given the option at postgis install time, if you'd like postgis_sfcgal too or you want to skip it.
But the packager would not need to have 2 versions of postgis lib anymore, the same postgis lib would service both kinds of users.


> > Those really aren't a big deal.   It's much more about depending on
> > additional packages.
> 
> The following already works:
> 
>   ./configure --without-raster --without-sfcgal --without-topology
> 
> --strk;
> 
>   Libre GIS consultant/developer 🎺
>   https://strk.kbt.io/services.html

Yes and also just to speed testing up, I just disable them temporarily to speed up my testing if I'm only focusing on say postgis extension or I'm getting regression failures on one I don't want to be distracted by.