A pg_extended_date_support extension has been added. This extension adds support for infinite and BC dates/timestamps on PostgreSQL.
The postgres adapter already had a convert_infinite_timestamps setting, but it wasn't supported in the jdbc/postgresql adapter and it didn't handle BC dates/timestamps. Setting a non-default convert_infinite_timestamps setting in the postgres adapter will now automatically load the extension for backwards compatibility.
The pg_extended_date_support extension by default just fixes the handling of BC dates/timestamps. To get it to handle infinite timestamps, you need to choose the appropriate setting for your application:
DB.extension :pg_extended_date_support DB.convert_infinite_timestamps = :string # or :float or :nil
This extension also enables the handling of timezone offsets with seconds, which is not natively supported by ruby's Time class in ruby <2.5.
The jdbc/mysql adapter now handles smallint unsigned and integer unsigned column types where the value for the column is outside of the range of a Java short or integer.
Sequel::Model.inherited no longer modifies an existing @dataset instance variable if one has already been set. This fixes a regression that was introduced in Sequel 5.0.0.