Some of you might have seen that the Greenplum database source code has been published:
https://adtmag.com/articles/2015/10/28/greenplum-open-sourced.aspx under the Apache 2.0 license: http://www.apache.org/licenses/LICENSE-2.0 The source code has known patents owned by Pivotal/Greenplum. The license has a patent grant clause: 3. Grant of Patent License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work, where such license applies only to those patent claims licensable by such Contributor that are necessarily infringed by their Contribution(s) alone or by combination of their Contribution(s) with the Work to which such Contribution(s) was submitted. If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed. However, while the license defines and uses "Derivative Works", it does not mention that in the patent grant clause. I assume this means that patent grants do not apply to derived works, meaning if code or ideas were moved from Greenplum to Postgres (which is not Apache 2.0 licensed), it would not have a patent grant. I talked to Greenplum staff about this a few months ago and they did not dispute my analysis. Therefore, I caution people from viewing the Greenplum source code as you might see patented ideas that could be later implemented in Postgres, opening Postgres up to increased patent violation problems. I am also concerned about existing community members who work for Pivotal/Greenplum and therefore are required to view the patented source code. The license issue might eventually be improved by Pivotal/Greenplum, but, for now, I think caution is necessary. Of course, never mention known-patented ideas in any community forum, including this email list. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Roman grave inscription + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers