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amorynan · Dec 12, 2024 · 10b2aa7 · 10b2aa7
1 parent 875ea65
commit 10b2aa7
Showing 1 changed file with 12 additions and 0 deletions.
diff --git a/be/src/olap/rowset/segment_v2/column_reader.cpp b/be/src/olap/rowset/segment_v2/column_reader.cpp
@@ -871,6 +871,10 @@ Status MapFileColumnIterator::next_batch(size_t* n, vectorized::MutableColumnPtr
         size_t num_read = *n;
         auto null_map_ptr =
                 static_cast<vectorized::ColumnNullable&>(*dst).get_null_map_column_ptr();
+        // in not-null to null linked-schemachange mode,
+        // actually we do not change dat data include meta in footer,
+        // so may dst from changed meta which is nullable but old data is not nullable,
+        // if so, we should set null_map to all null by default
         if (_null_iterator) {
             bool null_signs_has_null = false;
             RETURN_IF_ERROR(
@@ -938,6 +942,10 @@ Status StructFileColumnIterator::next_batch(size_t* n, vectorized::MutableColumn
         size_t num_read = *n;
         auto null_map_ptr =
                 static_cast<vectorized::ColumnNullable&>(*dst).get_null_map_column_ptr();
+        // in not-null to null linked-schemachange mode,
+        // actually we do not change dat data include meta in footer,
+        // so may dst from changed meta which is nullable but old data is not nullable,
+        // if so, we should set null_map to all null by default
         if (_null_iterator) {
             bool null_signs_has_null = false;
             RETURN_IF_ERROR(
@@ -1098,6 +1106,10 @@ Status ArrayFileColumnIterator::next_batch(size_t* n, vectorized::MutableColumnP
         auto null_map_ptr =
                 static_cast<vectorized::ColumnNullable&>(*dst).get_null_map_column_ptr();
         size_t num_read = *n;
+        // in not-null to null linked-schemachange mode,
+        // actually we do not change dat data include meta in footer,
+        // so may dst from changed meta which is nullable but old data is not nullable,
+        // if so, we should set null_map to all null by default
         if (_null_iterator) {
             bool null_signs_has_null = false;
             RETURN_IF_ERROR(