2020-05 updates

[mjpieters]

This brings mbdata up to par with MB Server again.

• Fix Python-2-ism in gentools.py
• Run the SQL and model generation steps
• Update the fresh install instructions (new script to run)
• Add notes on upgrading to PostgreSQL 12.

[mjpieters]

The updates/20200518-pg12-after-upgrade.sql script probably needs some custom re-writing.

I had to run the extensions alterations by hand as a superuser, and alter the role name in two other statements.

[sfussenegger]

Thanks for your effort!

The updates/20200518-pg12-after-upgrade.sql script probably needs some custom re-writing.

I had to run the extensions alterations by hand as a superuser, and alter the role name in two other statements.

Could you please elaborate on this?

[mjpieters]

I had to run the extensions alterations by hand as a superuser, and alter the role name in two other statements.

The before- and after-upgrade scripts appear to have two purposes:

• Dropping indexes and functions that are no longer used for anything
• Replace indexes and custom functions to move to native PG functionality rather than using custom extensions. This includes adding a dependency on the unaccent extension
• Correcting for past errors as to where extensions are registered (specifically the cube extension, for which a new bridge function in the musicbrainz schema is created).

The commands altering or creating extensions need superuser access, so can't be run directly with mbslave. In addition, there are two lines that assign ownership for two functions, and these hardcode the owner role. In our setup we use a different role name so I had to alter those statements accordingly.

[dltacube]

Hey @lalinsky , any reason for delaying this pull request? I'm thinking of using this branch before my upgrade :)

[dltacube]

Thanks @lalinsky