jackylee-ch commented on code in PR #15814:
URL: https://github.com/apache/iceberg/pull/15814#discussion_r3036642661


##########
docs/docs/flink-ddl.md:
##########
@@ -45,6 +45,23 @@ The following properties can be set if using the Hive 
catalog:
 * `hive-conf-dir`: Path to a directory containing a `hive-site.xml` 
configuration file which will be used to provide custom Hive configuration 
values. The value of `hive.metastore.warehouse.dir` from 
`<hive-conf-dir>/hive-site.xml` (or hive configure file from classpath) will be 
overwritten with the `warehouse` value if setting both `hive-conf-dir` and 
`warehouse` when creating iceberg catalog.
 * `hadoop-conf-dir`: Path to a directory containing `core-site.xml` and 
`hdfs-site.xml` configuration files which will be used to provide custom Hadoop 
configuration values.
 
+!!! warning "Hive Catalog Limitation"
+    The Hive Metastore validates schema changes by comparing column types 
**positionally**
+    (`hive.metastore.disallow.incompatible.col.type.changes`, default `true`). 
When using a Hive catalog,
+    schema evolution operations that change column positions — such as 
dropping a non-last column or
+    reordering columns — may fail regardless of which engine performs the 
change (Spark, Flink Java API, etc.).
+
+    To work around this, disable the HMS schema compatibility check by setting
+    `hive.metastore.disallow.incompatible.col.type.changes=false`:
+
+    - **Remote HMS:** Set this property in the HMS server's `hive-site.xml`.
+    - **Embedded HMS:** Add the equivalent property to the Hive catalog 
configuration.

Review Comment:
   The `Embedded HMS` means using HMS with derby, which is launching in the 
Flink JM.



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