背景:
原表为唯一键模型，如下：
CREATE TABLE `xx_table` (
`create_time` datetime(3) NULL COMMENT '创建时间',
`order_id` BIGINT NULL COMMENT '订单ID',
`update_time` datetime(3) NULL COMMENT '更新时间',
....
`ds_insert_time` datetime(3) NULL COMMENT '数据写入时间'
) ENGINE=OLAP
UNIQUE KEY(`create_time`, `order_id`)
PARTITION BY RANGE(`create_time`)
(PARTITION p20250316 VALUES [('2025-03-16 00:00:00'), ('2025-03-17 00:00:00')),
.....
PARTITION p20250402 VALUES [('2025-04-02 00:00:00'), ('2025-04-03 00:00:00')))
DISTRIBUTED BY HASH(`order_id`) BUCKETS 10
PROPERTIES (
"replication_allocation" = "tag.location.default: 3",
"is_being_synced" = "false",
"colocate_with" = "xxxx_order_id",
"dynamic_partition.enable" = "true",
"dynamic_partition.time_unit" = "DAY",
"dynamic_partition.time_zone" = "Asia/Shanghai",
"dynamic_partition.start" = "-15",
"dynamic_partition.end" = "2",
"dynamic_partition.prefix" = "p",
"dynamic_partition.replication_allocation" = "tag.location.default: 3",
"dynamic_partition.buckets" = "10",
"dynamic_partition.create_history_partition" = "true",
"dynamic_partition.history_partition_num" = "-1",
"dynamic_partition.hot_partition_num" = "0",
"dynamic_partition.reserved_history_periods" = "NULL",
"dynamic_partition.storage_policy" = "",
"storage_medium" = "hdd",
"storage_format" = "V2",
"enable_unique_key_merge_on_write" = "true",
"light_schema_change" = "true",
"disable_auto_compaction" = "false",
"enable_single_replica_compaction" = "false"
);
建表之初没有指定数据更新合并顺序字段，后续看文档想通过Alter的方式添加序列信息（routine load 增加order by update_time），执行操作后发现，操作ALTER前的历史数据，在ALTER 后更新时，无法即时在查询层显示合并效果，导致COUNT和COUNT(distinct order_id)数据结果不一致；唯一键模型数据出现两条
如下：
