AGPL? This is dead in the water :( It will never be integrated into PG. What a shame. It should have been a 2 clause BSDL. Sigh.
To use open source code, the more permissive the license the better. But to actually open your own code, BSDL is a very tough sell.
That's also why they use the AGPL. With database systems, even if they were under the GPL, some competitors could just modify the system and run it on their own server with improvements, and offer just the service to their clients. Again, the improvements go one way only: since the competitor would not distribute the modified system, as it's running on their servers, they would not need to distribute source changes. With the AGPL, that loophole is closed.
They are of course free to release their code under any license they wish. I just think releasing code under the *GPL when you profited from a liberal BSDL is a douche nozzle thing to do. But knock yourself out! This tells me all I need to know about the company.
Would CitusDB have been created at all were it not because they could sell a propietary fork as they have been doing in the past?
I'm a GPL zealot, to the point that I've used the GPL as a weapon and as a shield against others in multiple capacities ("You own all my code when you employ me? Sure, as long as I get to dictate the license"). However, I would never take someone's 2 or 3-clause BSD-licensed product, and relicense. Those of us that value sofware freedom value the rights of other licenses that believe the same.
We all see why it was done in this case, however; In order to ensure software freedom in the cloud (someone else's computer), there isn't another license to use. the BSD license completely breaks down in this use scenario, and the best we have is AGPL.
I'd say cloud usage is to 3-clause BSD what Tivo was to GPLv2.
If this were true then Cloudera, Horton and a whole bunch of other companies would be out of business, yet in reality they are doing really well. All that AGPL is doing for Citus is:
1. Turning away people (customers) who are religious about licenses.
2. Eliminating any possibility of this code ever being integrated into PostgreSQL
My $employer paid Hortonworks for a support contract and I have no qualms declaring publicly that it was a total and utter scam. (We are a Java shop and know our shit)
If I go into too much detail I'll write countless pages like my internal report on why we needed to switch, but the bottom line is that Cloudera's products are well and honestly documented, while, as of last year, Hortonworks' products are simply one land-mine after another.
Their management platform (Cloudera manager) being closed-source is barely a mark on the comparison analysis when you compare it to Ambari in practice. Ambari is a bad joke and I'd rather do without it after spending significant time using it and trying to extend it.
And I could go into excruciating detail as to how Hortonworks abuses the Apache License to try and force lock-in. It's disgusting and pathetic.
Cloudera also makes (Apache Licensed) Impala, which IMHO is a pretty cool product.
Another company worth mentioning is Databricks, which leads Apache Spark development.