May 2016 schema change release details

In about two months time we’ll have the next schema change release: May 16, 2016. Even after skipping the fall schema change release, this release is going to have few changes that will impact our downstream users. Most of the tickets in this release will make minor improvements to database indexes and edit tables. If you are one of the few users of our edit data, then you should delve deeper into the list of tickets in this release. For everyone else, I will summarize the tickets with a greater impact.

In a previous blog post we also talked about upgrading the minimum required version of postgres. We received no real feedback requesting for us to upgrade to 9.4, but we did receive some feedback that some people would prefer 9.5, which is our preference as well. Based on that feedback, we’re going to make PostgreSQL version 9.5 the minimum required version. If you’d like to run a MusicBrainz replicated instance via our Live Data Feed, you will need to run Postgres 9.5!

The official minimum supported Ubuntu release as of now is still Ubuntu 10.04 LTS (Lucid Lynx) which reached end-of-life a year ago. We will upgrade that to Ubuntu 14.04 LTS (Trusty Tahr) at the schema change release. In particular, this means that we might start using Perl 5.18 features in the MusicBrainz Server code (as opposed to Perl 5.10 currently).

We understand that this is potentially a lot of work for some of our users, but occasionally we need to upgrade our requirements. We try and limit these sorts of upgrades as much as possible, so please bear with us.

Finally onward to the details of the release. Please take a look at the list of issues that will be addressed in this release. The few tickets worth discussing in details are:

• MBS-8838 – “Add gids to all *_type tables“. This ticket adds MBIDs (GIDs in schema lingo) to all of our tables that define a type for some database element. Given that we recommend that external users never reference our data by row ids, we really need to provide proper permanent MBIDs to all elements of our database.
• MBS-6024 – “Support more than one barcode on same release (SQL edition)“. This ticket adds the ability for the database to contain more than one barcode for a given release. However, this ticket does not include the user interface portions of this feature. The team will add the user interface/edit portions of this feature in a later, non schema change release.
• MBS-4501 – “Alternative tracklists“. This ticket creates a new feature that would allow an alternative tracklist to be used for a given release. This is a better solution for handling conflicts between our style guidelines and how the data appears on the release. It is also a more elegant solution for translations of releases into different languages.

As usual, we will post final details about the release shortly before the release happens. If you have any questions about this release, feel free to ask specific questions in the tickets or general questions in the comments below.

(Edited 2016-03-16 at 12:55 UTC to add the upgraded Ubuntu requirement.)