data_source_exists?

# File activerecord/lib/active_record/connection_adapters/schema_cache.rb, line 309
      def data_source_exists?(pool, name)
        return if ignored_table?(name)

        if @data_sources.empty?
          tables_to_cache(pool).each do |source|
            @data_sources[source] = true
          end
        end

        return @data_sources[name] if @data_sources.key? name

        @data_sources[deep_deduplicate(name)] = pool.with_connection do |connection|
          connection.data_source_exists?(name)
        end
      end