Fix group by pushdown to rle/const decoder

src/storage/blocksstable/encoding/ob_const_decoder.cpp

@@ -897,6 +897,8 @@ int ObConstDecoder::read_distinct(
       ctx.col_header_->length_ - meta_header_->offset_,
       group_by_cell))) {
     LOG_WARN("Failed to load dict", K(ret));
+  } else if (has_null_execption_value()) {
+    group_by_cell.add_distinct_null_value();
   }
   return ret;
 }
@@ -919,5 +921,22 @@ int ObConstDecoder::read_reference(
   return ret;
 }
 
+bool ObConstDecoder::has_null_execption_value() const
+{
+  int ret = OB_SUCCESS;
+  bool has_null = false;
+  const int64_t dict_count = dict_decoder_.get_dict_header()->count_;
+  if (meta_header_->const_ref_ == dict_count) {
+    has_null = true;
+  } else {
+    int64_t ref;
+    for (int64_t pos = 0; !has_null && pos < meta_header_->count_; ++pos) {
+      ref = reinterpret_cast<const uint8_t*>(meta_header_->payload_)[pos];
+      has_null = ref >= dict_count;
+    }
+  }
+  return has_null;
+}
+
 } // end namespace blocksstable
 } // end namespace oceanbase

src/storage/blocksstable/encoding/ob_const_decoder.h

@@ -147,6 +147,8 @@ private:
       int64_t &null_count,
       uint32_t *ref_buf = nullptr) const;
 
+  bool has_null_execption_value() const;
+
 private:
   const ObConstMetaHeader *meta_header_;
   ObDictDecoder dict_decoder_;

src/storage/blocksstable/encoding/ob_dict_decoder.cpp

@@ -1471,7 +1471,16 @@ int ObDictDecoder::read_distinct(
     const char **cell_datas,
     storage::ObGroupByCell &group_by_cell) const
 {
-  return batch_read_distinct(ctx, cell_datas, ctx.col_header_->length_, group_by_cell);
+  int ret = OB_SUCCESS;
+  bool has_null = false;
+  if (OB_FAIL(batch_read_distinct(ctx, cell_datas, ctx.col_header_->length_, group_by_cell))) {
+    LOG_WARN("Failed to batch read distinct", K(ret));
+  } else if (check_has_null(ctx, ctx.col_header_->length_, has_null)) {
+    LOG_WARN("Failed to check has null", K(ret));
+  } else if (has_null) {
+    group_by_cell.add_distinct_null_value();
+  }
+  return ret;
 }
 
 int ObDictDecoder::batch_read_distinct(
@@ -1485,7 +1494,6 @@ int ObDictDecoder::batch_read_distinct(
   const char *dict_payload = meta_header_->payload_;
   const common::ObObjType obj_type = ctx.col_header_->get_store_obj_type();
   common::ObDatum *datums = group_by_cell.get_group_by_col_datums_to_fill();
-  bool has_null = false;
   group_by_cell.set_distinct_cnt(count);
   if (meta_header_->is_fix_length_dict()) {
     const int64_t dict_data_size = meta_header_->data_size_;
@@ -1513,10 +1521,6 @@ int ObDictDecoder::batch_read_distinct(
   }
   if (OB_FAIL(batch_load_data_to_datum(obj_type, cell_datas, count, integer_mask_, datums))) {
     LOG_WARN("Failed to batch load data to datum", K(ret));
-  } else if (check_has_null(ctx, meta_length, has_null)) {
-    LOG_WARN("Failed to check has null", K(ret));
-  } else if (has_null) {
-    group_by_cell.add_distinct_null_value();
   }
   return ret;
 }

src/storage/blocksstable/encoding/ob_rle_decoder.cpp

@@ -570,6 +570,8 @@ int ObRLEDecoder::read_distinct(
       ctx.col_header_->length_ - meta_header_->offset_,
       group_by_cell))) {
     LOG_WARN("Failed to load dict", K(ret));
+  } else if (has_null_value()) {
+    group_by_cell.add_distinct_null_value();
   }
   return ret;
 }
@@ -588,5 +590,19 @@ int ObRLEDecoder::read_reference(
   return ret;
 }
 
+bool ObRLEDecoder::has_null_value() const
+{
+  int ret = OB_SUCCESS;
+  bool has_null = false;
+  int64_t ref;
+  const int64_t dict_count = dict_decoder_.get_dict_header()->count_;
+  const ObIntArrayFuncTable &refs = ObIntArrayFuncTable::instance(meta_header_->ref_byte_);
+  for (int64_t i = 0; !has_null && i < meta_header_->count_; ++i) {
+    ref = refs.at_(meta_header_->payload_ + ref_offset_, i);
+    has_null = ref >= dict_count;
+  }
+  return has_null;
+}
+
 } // end namespace blocksstable
 } // end namespace oceanbase

src/storage/blocksstable/encoding/ob_rle_decoder.h

@@ -150,6 +150,8 @@ private:
       const int64_t row_cap,
       storage::ObGroupByCell &group_by_cell) const override;
 
+  bool has_null_value() const;
+
 private:
   const ObRLEMetaHeader *meta_header_;
   uint16_t ref_offset_;