Fix: Address code review feedback and drop stateless test

- Addressed Arthur's review comments (removed redundant isDataLake check, reverted IDataLakeMetadata.h signature).
- Removed the stateless SQL test entirely. Iceberg table bootstrapping requires external catalog initialization, which is fully covered by the PyIceberg integration tests.

Author: Daniel Q. Kim

src/Storages/ObjectStorage/DataLakes/IDataLakeMetadata.h

@@ -142,7 +142,7 @@ class IDataLakeMetadata : boost::noncopyable
     virtual bool supportsWrites() const { return false; }
     virtual bool supportsParallelInsert() const { return false; }
 
-    virtual void modifyFormatSettings(FormatSettings & /*format_settings*/, const Context & /*local_context*/) const {}
+    virtual void modifyFormatSettings(FormatSettings &, const Context &) const {}
 
     virtual bool supportsTruncate() const { return false; }
     virtual void truncate(ContextPtr /*context*/, std::shared_ptr<DataLake::ICatalog> /*catalog*/, const StorageID & /*storage_id*/)

src/Storages/ObjectStorage/DataLakes/Iceberg/IcebergMetadata.cpp

@@ -538,13 +538,12 @@ void IcebergMetadata::truncate(ContextPtr context, std::shared_ptr<DataLake::ICa
         persistent_components.table_uuid);
 
     Int64 parent_snapshot_id = actual_table_state_snapshot.snapshot_id.value_or(0);
-    
     auto config_path = persistent_components.table_path;
     if (config_path.empty() || config_path.back() != '/')
         config_path += "/";
     if (!config_path.starts_with('/'))
         config_path = '/' + config_path;
-    
+
     FileNamesGenerator filename_generator;
     if (!context->getSettingsRef()[Setting::write_full_path_in_iceberg_metadata])
     {
@@ -559,15 +558,14 @@ void IcebergMetadata::truncate(ContextPtr context, std::shared_ptr<DataLake::ICa
         filename_generator = FileNamesGenerator(
             bucket, config_path, (catalog != nullptr && catalog->isTransactional()), persistent_components.metadata_compression_method, write_format);
     }
-    
+ 
     Int32 new_metadata_version = actual_table_state_snapshot.metadata_version + 1;
     filename_generator.setVersion(new_metadata_version);
-    
     auto [metadata_name, storage_metadata_name] = filename_generator.generateMetadataName();
 
     auto [new_snapshot, manifest_list_name, storage_manifest_list_name] = MetadataGenerator(metadata_object).generateNextMetadata(
-        filename_generator, metadata_name, parent_snapshot_id, 
-        /* added_files */ 0, /* added_records */ 0, /* added_files_size */ 0, 
+        filename_generator, metadata_name, parent_snapshot_id,
+        /* added_files */ 0, /* added_records */ 0, /* added_files_size */ 0,
         /* num_partitions */ 0, /* added_delete_files */ 0, /* num_deleted_rows */ 0);
 
     // generate manifest list with 0 manifest files
@@ -581,10 +579,9 @@ void IcebergMetadata::truncate(ContextPtr context, std::shared_ptr<DataLake::ICa
     );
     generateManifestList(filename_generator, metadata_object, object_storage, context, {}, new_snapshot, 0, *buf, Iceberg::FileContentType::DATA, false);
     buf->finalize();
-    
+
     String metadata_content = dumpMetadataObjectToString(metadata_object);
     writeMessageToFile(metadata_content, storage_metadata_name, object_storage, context, "*", "", persistent_components.metadata_compression_method);
-    
     if (catalog)
     {
         const auto & [namespace_name, table_name] = DataLake::parseTableName(storage_id.getTableName());

src/Storages/ObjectStorage/StorageObjectStorage.cpp

@@ -645,15 +645,12 @@ void StorageObjectStorage::truncate(
 
     if (configuration->isDataLakeConfiguration())
     {
-        if (isDataLake())
-        {
-            auto * data_lake_metadata = getExternalMetadata(context);
-            if (!data_lake_metadata || !data_lake_metadata->supportsTruncate())
-                throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Truncate is not supported for this data lake engine");
-            
-            data_lake_metadata->truncate(context, catalog, getStorageID());
-            return;
-        }
+        auto * data_lake_metadata = getExternalMetadata(context);
+        if (!data_lake_metadata || !data_lake_metadata->supportsTruncate())
+            throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Truncate is not supported for this data lake engine");
+ 
+        data_lake_metadata->truncate(context, catalog, getStorageID());
+        return;
     }
 
     if (path.hasGlobs())

tests/integration/test_storage_iceberg_no_spark/test_iceberg_truncate.py

@@ -36,7 +36,6 @@ def test_iceberg_truncate(started_cluster_iceberg_no_spark):
     )
 
     table_name = "test_truncate"
-    
     table = catalog.create_table(
         identifier=f"{namespace}.{table_name}",
         schema=schema,
@@ -63,7 +62,7 @@ def test_iceberg_truncate(started_cluster_iceberg_no_spark):
         SETTINGS catalog_type='rest', warehouse='demo', storage_endpoint='http://minio:9000/warehouse-rest';
         """
     )
-    
+
     # Assert data from ClickHouse
     assert int(instance.query(f"SELECT count() FROM {namespace}.{table_name}").strip()) == 3