Github user paul-rogers commented on a diff in the pull request:
https://github.com/apache/drill/pull/1170#discussion_r178225930
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/record/VectorContainer.java
---
@@ -136,14 +138,28 @@ public void transferOut(VectorContainer containerOut)
{
public <T extends ValueVector> T addOrGet(final MaterializedField field,
final SchemaChangeCallBack callBack) {
final TypedFieldId id =
getValueVectorId(SchemaPath.getSimplePath(field.getName()));
final ValueVector vector;
- final Class<?> clazz =
TypeHelper.getValueVectorClass(field.getType().getMinorType(),
field.getType().getMode());
+
if (id != null) {
- vector = getValueAccessorById(id.getFieldIds()).getValueVector();
+ vector =
getValueAccessorById(id.getFieldIds()).getValueVector();
+ final Class<?> clazz =
TypeHelper.getValueVectorClass(field.getType().getMinorType(),
field.getType().getMode());
+
+ // Check whether incoming field and the current one are compatible;
if not then replace previous one with the new one
if (id.getFieldIds().length == 1 && clazz != null &&
!clazz.isAssignableFrom(vector.getClass())) {
final ValueVector newVector = TypeHelper.getNewVector(field,
this.getAllocator(), callBack);
replace(vector, newVector);
return (T) newVector;
}
+
+ // At this point, we know incoming and current fields are
compatible. Maps can have children,
+ // we need to ensure they have the same structure.
+ if (MinorType.MAP.equals(field.getType().getMinorType())
+ && vector != null
+ &&
!SchemaUtil.isSameSchemaIncludingOrder(vector.getField().getChildren(),
field.getChildren())) {
+
+ final ValueVector newVector = TypeHelper.getNewVector(field,
this.getAllocator(), callBack);
+ replace(vector, newVector);
+ return (T) newVector;
--- End diff --
We have two vectors, both maps. We found out their schemas differ. We are
throwing away the old map, replacing it with a new one with no members. Is
that what we want to do? Or, do we want to recursively merge the maps? Is this
done elsewhere? If so, how do we remember to do that merge?
---
