[Docs]adding instructions for converting dynamic and manual partition tables to each other (#4994)

There is no clear instruction to manually modify partitions, when dynamic partition feature is enabled.
The user will be informed only after trying to modify the partition in the command line.
This PR adds instructions for converting dynamic and manual partition tables to each other

docs/en/administrator-guide/dynamic-partition.md

@@ -324,3 +324,20 @@ mysql> SHOW DYNAMIC PARTITION TABLES;
     
     `curl --location-trusted -u username:password -XGET http://fe_host:fe_http_port/api/_set_config?dynamic_partition_check_interval_seconds=432000`
     
+### Converting dynamic and manual partition tables to each other
+
+For a table, dynamic and manual partitioning can be freely converted, but they cannot exist at the same time, there is and only one state.
+
+#### Converting Manual Partitioning to Dynamic Partitioning
+
+If a table is not dynamically partitioned when it is created, it can be converted to dynamic partitioning at runtime by modifying the dynamic partitioning properties with `ALTER TABLE`, an example of which can be seen with `HELP ALTER TABLE`.
+
+When dynamic partitioning feature is enabled, Doris will no longer allow users to manage partitions manually, but will automatically manage partitions based on dynamic partition properties.
+
+**NOTICE**: If `dynamic_partition.start` is set, historical partitions with a partition range before the start offset of the dynamic partition will be deleted.
+
+#### Converting Dynamic Partitioning to Manual Partitioning
+
+The dynamic partitioning feature can be disabled by executing `ALTER TABLE tbl_name SET ("dynamic_partition.enable" = "false") ` and converting it to a manual partition table.
+
+When dynamic partitioning feature is disabled, Doris will no longer manage partitions automatically, and users will have to create or delete partitions manually by using `ALTER TABLE`.

docs/zh-CN/administrator-guide/dynamic-partition.md

@@ -321,3 +321,21 @@ mysql> SHOW DYNAMIC PARTITION TABLES;
     HTTP 协议：
     
     `curl --location-trusted -u username:password -XGET http://fe_host:fe_http_port/api/_set_config?dynamic_partition_check_interval_seconds=432000`
+
+### 动态分区表与手动分区表相互转换
+
+对于一个表来说，动态分区和手动分区可以自由转换，但二者不能同时存在，有且只有一种状态。
+
+#### 手动分区转换为动态分区
+
+如果一个表在创建时未指定动态分区，可以通过 `ALTER TABLE` 在运行时修改动态分区相关属性来转化为动态分区，具体示例可以通过 `HELP ALTER TABLE` 查看。
+
+开启动态分区功能后，Doris 将不再允许用户手动管理分区，会根据动态分区属性来自动管理分区。
+
+**注意**：如果已设定 `dynamic_partition.start`，分区范围在动态分区起始偏移之前的历史分区将会被删除。
+
+#### 动态分区转换为手动分区
+
+通过执行 `ALTER TABLE tbl_name SET ("dynamic_partition.enable" = "false")` 即可关闭动态分区功能，将其转换为手动分区表。
+
+关闭动态分区功能后，Doris 将不再自动管理分区，需要用户手动通过 `ALTER TABLE` 的方式创建或删除分区。