marton-bod commented on a change in pull request #2418:
URL: https://github.com/apache/hive/pull/2418#discussion_r658724347



##########
File path: 
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/hive/HiveIcebergMetaHook.java
##########
@@ -262,17 +264,52 @@ public void 
preAlterTable(org.apache.hadoop.hive.metastore.api.Table hmsTable, E
 
     if (AlterTableType.ADDCOLS.equals(currentAlterTableOp)) {
       Collection<FieldSchema> addedCols =
-          HiveSchemaUtil.schemaDifference(hmsTable.getSd().getCols(), 
HiveSchemaUtil.convert(icebergTable.schema()));
+          HiveSchemaUtil.newColumns(hmsTable.getSd().getCols(), 
HiveSchemaUtil.convert(icebergTable.schema()));
+      if (!addedCols.isEmpty()) {
+        updateSchema = icebergTable.updateSchema();
+      }
+      for (FieldSchema addedCol : addedCols) {
+        updateSchema.addColumn(
+            addedCol.getName(),
+            
HiveSchemaUtil.convert(TypeInfoUtils.getTypeInfoFromTypeString(addedCol.getType())),
+            addedCol.getComment()
+        );
+      }
+    } else if (AlterTableType.REPLACE_COLUMNS.equals(currentAlterTableOp)) {
+      List<FieldSchema> icebergSchema = 
HiveSchemaUtil.convert(icebergTable.schema());
+      List<FieldSchema> hmsSchema = hmsTable.getSd().getCols();
+      Collection<FieldSchema> droppedCols = 
HiveSchemaUtil.newColumns(icebergSchema, hmsSchema);
+      Collection<FieldSchema> addedCols = HiveSchemaUtil.newColumns(hmsSchema, 
icebergSchema);
+      Collection<FieldSchema> typeUpdated = 
HiveSchemaUtil.updatedTypeColumns(hmsSchema, icebergSchema);
+      Collection<FieldSchema> commentUpdated = 
HiveSchemaUtil.updatedCommentColumns(hmsSchema, icebergSchema);
+      if (!droppedCols.isEmpty() || !addedCols.isEmpty() || 
!typeUpdated.isEmpty() || !commentUpdated.isEmpty()) {
+        updateSchema = icebergTable.updateSchema();
+      }
+
+      for (FieldSchema droppedCol : droppedCols) {
+        updateSchema.deleteColumn(droppedCol.getName());
+      }
+
       for (FieldSchema addedCol : addedCols) {
-        if (updateSchema == null) {
-          updateSchema = icebergTable.updateSchema();
-        }
         updateSchema.addColumn(
             addedCol.getName(),
             
HiveSchemaUtil.convert(TypeInfoUtils.getTypeInfoFromTypeString(addedCol.getType())),
             addedCol.getComment()
         );
       }
+
+      for (FieldSchema updatedCol : typeUpdated) {
+        Type newType = 
HiveSchemaUtil.convert(TypeInfoUtils.getTypeInfoFromTypeString(updatedCol.getType()));
+        if (!(newType instanceof Type.PrimitiveType)) {

Review comment:
       The Iceberg library will throw an exception in that case, saying type 
promotion is not supported (e.g. int -> string)




-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
[email protected]



---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to