Antalya 26.6 - Drop partition for Iceberg

docs/en/sql-reference/statements/alter/partition.md

@@ -69,6 +69,22 @@ ALTER TABLE mt DROP PARTITION '2020-11-21';
 ALTER TABLE mt DROP PART 'all_4_4_0';
 ```
 
+On Iceberg tables, `DROP PARTITION` drops the partition by writing a new snapshot with the partition data files excluded.
+
+By default, no parquet files are physically deleted from object storage.
+The `iceberg_delete_data_on_drop` option must be enabled for data files to be purged.
+
+:::note
+Purging data files will break time travel to older snapshots that reference that partition.
+:::
+
+Example purging data files:
+
+```sql
+ALTER TABLE mt DROP PARTITION tuple(toRelativeDayNum(toDate('2026-01-01')))
+SETTINGS iceberg_delete_data_on_drop = 1;
+```
+
 ## DROP DETACHED PARTITION\|PART {#drop-detached-partitionpart}
 
 ```sql

src/Storages/ObjectStorage/DataLakes/IDataLakeMetadata.h

@@ -268,6 +268,15 @@ class IDataLakeMetadata : boost::noncopyable
         ContextPtr /*context*/,
         const StorageID & /*storage_id*/,
         std::shared_ptr<DataLake::ICatalog> /*catalog*/) { throwNotImplemented("alter"); }
+    virtual bool supportsDropPartition() const { return false; }
+    virtual void dropPartition(
+        const ASTPtr & /* partition */,
+        ContextPtr /* context */,
+        std::shared_ptr<DataLake::ICatalog> /* catalog */,
+        const StorageID & /* storage_id */)
+    {
+        throwNotImplemented("dropPartition");
+    }
 
     virtual Pipe executeCommand(
         const String & command_name,