Upgrade PostgreSQL to 11

[vgeorge]

Suggestion by Eric Sooros:

One further change that may be helpful -- the newer versions of postgresql (10+, but 12 especially when it's available on RDS) have improving support for parallelizing expensive queries. I think this would likely be helpful here, and at the very least, not harmful.

From my look at the code, this app doesn't appear to be doing anything that would cause issues with upgrading. I've run the upgrade on the dev-scale database in RDS and haven't seen any issues. (but, as you know, it's not a very complete system).

I believe we just need to test this change locally by upgrading PostgreSQL at Docker compose file. If there is no issues, we can migrate the production database.

I've just noticed that we are using a PostGIS image, which was set at the begining of the project. I think we can drop it, as no geo features are being used.

[EricSoroos]

The production RDS doesn't have the postgis extension installed in the db, so it's safe to use the non-postgis version in docker.

For now, I'd say we should go to 11, since that's the latest version that's fully supported on amazon.

[vgeorge]

@EricSoroos I believe we can move forward with the upgrade, but will it cause downtime for the new instance? Do you think it's safe to do this now or it's better to do after the launch?

[EricSoroos]

I don't know how long it's going to take, but I've got an RDS instance here, so I'll just run it on this one and see how long it takes. I'd rather do this before there are people on the site. We can test against this one and then if it's good, you can do your prod one.

It was pretty fast for the little DB, so it might be quick.

[EricSoroos]

It's saying 14% complete after 10 minutes upgrading. Nevermind, I don't think that's right.

[EricSoroos]

Done now, Looks like a total of 15 minutes.

[vgeorge]

Nice. I'll keep this open until we update the Docker compose file to use version 11 and drop PostGIS.