Terraform AWS红移地形模块：最终\u快照\u标识符

我使用AWS红移地形模块来设置红移。对于每个文档，不需要最终的\u快照\u标识符。但是，我错了， 错误：“最终\u快照\u标识符”中只允许字母数字字符和连字符。 文档中说，“final_snapshot_identifier：（可选）在删除集群之前立即创建的最终快照的标识符。如果提供了此参数，“skip_final_snapshot”必须为false”，我可以通过添加代码来解决此问题

final_snapshot_identifier  = var.final_snapshot_identifier
skip_final_snapshot        = true

但是，为什么

module "redshift" {
  source  = "terraform-aws-modules/redshift/aws"
  version = "2.7.0"

  #redshift_subnet_group_name = var.redshift_subnet_group_name
  subnets                    = data.terraform_remote_state.vpc.outputs.redshift_subnets
  #parameter_group_name       = var.parameter_group_name
  cluster_identifier         = var.cluster_identifier
  cluster_database_name      = var.cluster_database_name
  encrypted                  = false
  cluster_master_password    = var.cluster_master_password
  cluster_master_username    = var.cluster_master_username
  cluster_node_type          = var.cluster_node_type
  cluster_number_of_nodes    = var.cluster_number_of_nodes
  enhanced_vpc_routing       = false
  publicly_accessible        = true
  vpc_security_group_ids     = [module.sg.this_security_group_id]
  final_snapshot_identifier  = var.final_snapshot_identifier
  skip_final_snapshot        = true
}