| 场景 | 主键最新态 |
|---|---|
| 语法 | MERGE INTO ... WHEN MATCHED |
| 引擎 | Hive ACID / Doris Unique |
| 注意 | 分区条件与并发 |
MERGE 示例
MERGE 示例
MERGE INTO dim_customer AS t
USING stg_customer AS s
ON t.customer_id = s.customer_id
WHEN MATCHED AND s.update_time > t.update_time THEN UPDATE SET
t.customer_name = s.customer_name,
t.update_time = s.update_time
WHEN NOT MATCHED THEN INSERT (customer_id, customer_name, update_time)
VALUES (s.customer_id, s.customer_name, s.update_time);MERGE 在大分区表上扫描成本高，能按分区先过滤就先过滤。