instance method generate_index_name

# File activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb, line 1601
        def generate_index_name(table_name, column)
          name = "index_#{table_name}_on_#{Array(column) * '_and_'}"
          return name if name.bytesize <= max_index_name_size

          # Fallback to short version, add hash to ensure uniqueness
          hashed_identifier = "_" + OpenSSL::Digest::SHA256.hexdigest(name).first(10)
          name = "idx_on_#{Array(column) * '_'}"

          short_limit = max_index_name_size - hashed_identifier.bytesize
          short_name = name.mb_chars.limit(short_limit).to_s

          "#{short_name}#{hashed_identifier}"
        end