[postgis-devel] postgis extension sans raster (only for folks who can't compile with raster support) - PSC Vote and developer/packager comments please

[Paragon Corporation]

>> 1) changes nothing for existing users, makes it easier for people who can't get GDAL to still use the same instructions for  installing postgis like everyone else.
>> 2) As an instructor, making sure I can give you the same set of instructions to install and get going regardless what operating system you are on is really really important to me as these detours of (if you don't have raster -- here is who you find where your scripts are installed is a big PITA)
>> It seems to me that the same instructions:

>  CREATE EXTENSION postgis;

> would result in either having PostGIS with raster or PostGIS without raster, depending on how the package was built.

Correct by design.  It's the least invasive way possible to keep business as usual for most users and allow users forced to install with scripts currently to be able to install with extension system.


> Alse these instructions:

>  ALTER EXTENSION postgis UPDATE;

> would be ambiguous as to what the target version would be.

This is never ambiguous (I mean not programmatically anyway).  To the user maybe.
There is only ever one target version per extension and an UPDATE without explicitly specifying a target version takes your version to the target version period.

a) So if you have no-raster you are going to the next no-raster version
b) If you have raster you are going to the next raster version
c) If you had no-raster and now have raster --> you are going to a postgis with raster (and we only provide script for a parallel -- this we may need to think a bit on)
d) if you had raster and now have no raster -> you are going from raster to no raster and will get an upgrade failure if you are actually using raster in your data.



> By having the same name "postgis" we're forced to have the same control file, which in turn can only point to a single "default_version".
Yes exactly and by design.  We don't want extensions upstream having to make conditional scripts for postgis , postgis-no-raster  which is why it has to be the same extension.
Trying to take raster out of existing postgis extension is too big of a breaking change for 95% of folks.


> So at the bare minimum, instructions for using postgis raster should always add a step to make sure raster was included.
> --strk;

Yes I will update instructions as part of the work if either Paul Ramsey or Mark Cave-Ayland can give me a +1
Technically we could push this even as far back as 2.1.9 since it's a packaging revision (bug) rather than a code revision.  But I won't fight for that just yet :)


Thanks,
Regina