[R-sig-DB] license issues R vs. PostgreSQL

[Joe Conway]

ripley using stats.ox.ac.uk wrote:
> libR is GPL-ed, and that is unlikely to change.

Thank you. That explicit confirmation was what I've been looking for.


> Already R has interfaces to (and has been embedded into) several DBMSs,
> included being previously embedded into PostgreSQL (by Duncan Temple Lang,
> with sources formerly at least on www.omegahat.org, and still accessible
> on CRAN/Omegahat, so it may well be still on www.omegahat.org).  I am
> afraid I don't see what makes PL/R (which we have not seen) a special
> case.

You haven't seen code yet because I didn't want to make a public posting 
with the wrong license.

PL/R isn't special compared to REmbeddedPostgres, but they both are 
quite different than, say, RMySQL. The standard DBMS interfaces are from 
R to the database using the databases' client libraries. Those libraries 
are relatively stable interfaces to their respective databases.

On the other hand, here is Duncan's note from the top of the 
REmbeddedPostgres INSTALL file:

**********************************************************************
Note:

  Before compiling this package, you will _have to_ have the source for
  Postgres. The regular header files that are installed when Postgres
  is installed are not sufficient since this package does not use the
  client interface, but the internal facilities of the Postgres server.

**********************************************************************

The same is true of PL/R. In this case the interface is from Postgres to 
R using R's standard interface library, which I presume is intended to 
be reasonably stable. Because of this issue, I'd be amazed if 
REmbeddedPostgres would even compile against current Postgres sources, 
because there have been huge changes since PostgreSQL 7.0.2 that Duncan 
wrote to.

PL/R (and REmbeddedPostgres) could be said to be loosely coupled to R, 
and tightly coupled to Postgres. The advantage of having such in the 
Postgres source tree is significant -- as the backend code evolves, PL/R 
comes along for the ride.

But I guess all of the above is moot, because I'll need to release PL/R 
under GPL, meaning it will not be accepted into the PostgreSQL source 
tree (I have already asked). So I'll change the license blocks in my 
code from BSD to GPL and get on with it.

I'd very much like feedback from some R developers before a general 
release -- would anyone be willing to give it a look if I post a link? 
(after changing the license to GPL of course ;-))

Thanks for your time,

Joe