Add timestamptz as a time zone aware type for PostgreSQL

[ghiculescu]

#41395 added support for the timestamptz type on the Postgres adapter.

As we found here this causes issues because in some scenarios the new type is not considered a time zone aware attribute, meaning values of this type in the DB are presented as a Time, not an ActiveSupport::TimeWithZone.

This PR fixes that by ensuring that timestamptz is always a time zone aware type, for Postgres users. A workaround is to do this in an initializer:

ActiveRecord::Base.time_zone_aware_types << :timestamptz

Or if you don't want this you can opt out in an initializer:

ActiveRecord::Base.time_zone_aware_types -= [:timestamptz]

I think this should be backported to 7-0-stable.

Fixes #45270

[yahonda]

Let me take a look at it.

[yahonda]

Before diving into implementation details, Can I get your opinion about adding tstzrange type also as time_zone_aware_types ?

Background is Based #45348

In PostgreSQL, tstzrange is "range of timestamp with time zone" so I think we can define tstzrange as timezone aware types in Rails. on the other hand, tsrange is "Range of timestamp without time zone" so I prefer not to make tsrange type as timezone aware time_zone_aware_types by default. Users can opt-in tsrange as time_zone_aware_types if necessary.

https://www.postgresql.org/docs/current/rangetypes.html

8.17.1. Built-in Range and Multirange Types
PostgreSQL comes with the following built-in range types:

• tsrange — Range of timestamp without time zone, tsmultirange — corresponding Multirange
• tstzrange — Range of timestamp with time zone, tstzmultirange — corresponding Multirange

cc @morgoth

[ghiculescu]

Yep, that sounds reasonable. I'll add it to this PR.

[ghiculescu]

@yahonda updated 👍

[morgoth]

@yahonda Currently Rails is configured to use timezone awareness for "timestamp" column type.

It's a bit confusing when the AR logic should be used - should it be for columns without "tz" (to add it to columns that do not support it natively) or with "tz" (that supposed to support it natively)?

[ghiculescu]

Hmm, we use this as an example:

rails/activerecord/lib/active_record/timestamp.rb

Line 35 in 85f4535

# ActiveRecord::Base.time_zone_aware_types += [:tsrange, :tstzrange]

So maybe it's intentionally not included by default. I'll remove it from this PR. We can re-add in a separate PR if needed.

[yahonda]

@morgoth Thanks for the explanation. Agreed it is difficult to say timezone aware types in Rails just because the database column is timezone aware. Let's keep it as it is.

[ghiculescu]

I rebased again. Keeping the changelog up to date is a full time job 😆

[yahonda]

Looks good to me. Would you address the conflict with CHANGELOG.md?

[yahonda]

Considering #45270 this is a regression in Rails 7.0 .z then backported to 7-0-stable via 4cd5709

[ghiculescu]

Thanks for all your help @yahonda !