[Doc] Add a description of the restriction of the materialized view on the use of the unique model (#6362)

Add a description of the restriction of the materialized view on the use of the unique model

docs/en/administrator-guide/materialized_view.md

@@ -486,6 +486,7 @@ This problem can be solved by creating a materialized view with k3 as the first
 2. If the conditional column of the delete statement does not exist in the materialized view, the delete operation cannot be performed. If you must delete data, you need to delete the materialized view before deleting the data.
 3. Too many materialized views on a single table will affect the efficiency of importing: When importing data, the materialized view and base table data are updated synchronously. If a table has more than 10 materialized view tables, it may cause the import speed to be very high. slow. This is the same as a single import needs to import 10 tables at the same time.
 4. The same column with different aggregate functions cannot appear in a materialized view at the same time. For example, select sum(a), min(a) from table are not supported.
+5. For the Unique Key data model, the materialized view can only change the column order and cannot play the role of aggregation. Therefore, in the Unique Key model, it is not possible to perform coarse-grained aggregation operations on the data by creating a materialized view.
 
 ## Error
 1. DATA_QUALITY_ERR: "The data quality does not satisfy, please check your data"

docs/zh-CN/administrator-guide/materialized_view.md

@@ -488,6 +488,7 @@ MySQL [test]> desc advertiser_view_record;
 2. 如果删除语句的条件列，在物化视图中不存在，则不能进行删除操作。如果一定要删除数据，则需要先将物化视图删除，然后方可删除数据。
 3. 单表上过多的物化视图会影响导入的效率：导入数据时，物化视图和 base 表数据是同步更新的，如果一张表的物化视图表超过10张，则有可能导致导入速度很慢。这就像单次导入需要同时导入10张表数据是一样的。
 4. 相同列，不同聚合函数，不能同时出现在一张物化视图中，比如：select sum(a), min(a) from table 不支持。
+5. 物化视图针对 Unique Key数据模型，只能改变列顺序，不能起到聚合的作用，所以在Unique Key模型上不能通过创建物化是视图的方式对数据进行粗粒度聚合操作
 
 ## 异常错误
 1. DATA_QUALITY_ERR: "The data quality does not satisfy, please check your data"