diff --git a/deps/oblib/src/lib/udt/ob_array_type.cpp b/deps/oblib/src/lib/udt/ob_array_type.cpp
index a35243fa5..e40187e03 100644
--- a/deps/oblib/src/lib/udt/ob_array_type.cpp
+++ b/deps/oblib/src/lib/udt/ob_array_type.cpp
@@ -609,12 +609,14 @@ int ObArrayBinary::get_data_binary(char *res_buf, int64_t buf_len)
     ret = OB_ERR_UNEXPECTED;
     OB_LOG(WARN, "buf len isn't enough", K(ret), K(buf_len));
   } else if (data_container_ == NULL) {
-    uint32_t last_idx = length_ > 0 ? length_ - 1 : 0;
-    MEMCPY(res_buf + pos, reinterpret_cast<char *>(null_bitmaps_), sizeof(uint8_t) * length_);
-    pos += sizeof(uint8_t) * length_;
-    MEMCPY(res_buf + pos, reinterpret_cast<char *>(offsets_), sizeof(uint32_t) * length_);
-    pos += sizeof(uint32_t) * length_;
-    MEMCPY(res_buf + pos, data_, offsets_[last_idx]);
+    if (length_ > 0) {
+      uint32_t last_idx = length_ - 1;
+      MEMCPY(res_buf + pos, reinterpret_cast<char *>(null_bitmaps_), sizeof(uint8_t) * length_);
+      pos += sizeof(uint8_t) * length_;
+      MEMCPY(res_buf + pos, reinterpret_cast<char *>(offsets_), sizeof(uint32_t) * length_);
+      pos += sizeof(uint32_t) * length_;
+      MEMCPY(res_buf + pos, data_, offsets_[last_idx]);
+    }
   } else {
     MEMCPY(res_buf + pos, reinterpret_cast<char *>(data_container_->null_bitmaps_.get_data()), sizeof(uint8_t) * data_container_->null_bitmaps_.size());
     pos += sizeof(uint8_t) * data_container_->null_bitmaps_.size();
diff --git a/deps/oblib/src/lib/udt/ob_array_type.h b/deps/oblib/src/lib/udt/ob_array_type.h
index c1e213de0..a6dc5cecd 100644
--- a/deps/oblib/src/lib/udt/ob_array_type.h
+++ b/deps/oblib/src/lib/udt/ob_array_type.h
@@ -936,8 +936,10 @@ public :
   {
     int32_t len = 0;
     if (this->data_container_ == NULL) {
-      uint32_t last_idx = this->length_ > 0 ? this->length_ - 1 : 0;
-      len = this->length_ * sizeof(uint8_t) + this->length_ * sizeof(uint32_t) + this->offsets_[last_idx];
+      if (this->length_ > 0) {
+        uint32_t last_idx = this->length_ - 1;
+        len = this->length_ * sizeof(uint8_t) + this->length_ * sizeof(uint32_t) + this->offsets_[last_idx];
+      }
     } else {
       len = sizeof(uint8_t) * data_container_->null_bitmaps_.size()
                                         + sizeof(uint32_t) * data_container_->offsets_.size()