Create duplicate table via an ActiveRecord migration

12341234123123_example_migration.rb

class ExampleMigration < ActiveRecord::Migration[5.2]
  def up
    # ? Create the new table with the same structure as the old table
    # ? https://www.postgresql.org/docs/9.3/sql-createtable.html
    execute <<-SQL
      CREATE TABLE new_table (LIKE old_table INCLUDING ALL);
    SQL

    # * removing any unneeded columns will also remove related indexes and constraints
    remove_column :new_table, :old_column
  end

  def down
    drop_table :new_table
  end
end