diff --git a/src/sql/session/ob_basic_session_info.cpp b/src/sql/session/ob_basic_session_info.cpp
index f77871a7e039f21621e1b38d818174e42498d469..a5cd68bccc67c091d57bb4f88b9e851ac97bda6f 100644
--- a/src/sql/session/ob_basic_session_info.cpp
+++ b/src/sql/session/ob_basic_session_info.cpp
@@ -3955,7 +3955,7 @@ int ObBasicSessionInfo::store_query_string(const ObString& stmt)
 int ObBasicSessionInfo::store_query_string_(const ObString& stmt)
 {
   int ret = OB_SUCCESS;
-  int64_t truncated_len = std::min(MAX_CUR_QUERY_LEN - 1, static_cast<int64_t>(stmt.length()));
+  int64_t truncated_len = std::min(MAX_QUERY_STRING_LEN - 1, static_cast<int64_t>(stmt.length()));
   if (truncated_len < 0) {
     ret = OB_INVALID_ARGUMENT;
     LOG_WARN("invalid str length", K(ret), K(truncated_len));
diff --git a/src/sql/session/ob_basic_session_info.h b/src/sql/session/ob_basic_session_info.h
index 1f422eac02c6ad2f8063f06788b29005b91b2d3c..450efd3ccc372de4d11c3cbcb2e03cfab5d09191 100644
--- a/src/sql/session/ob_basic_session_info.h
+++ b/src/sql/session/ob_basic_session_info.h
@@ -186,6 +186,7 @@ public:
 
   static const int64_t MIN_CUR_QUERY_LEN = 512;
   static const int64_t MAX_CUR_QUERY_LEN = 16 * 1024;
+  static const int64_t MAX_QUERY_STRING_LEN = 64 * 1024;
   class TransFlags {
   public:
     TransFlags() : flags_(0)
@@ -1273,7 +1274,8 @@ public:
   /// @}
   int64_t get_session_info_mem_size() const { return block_allocator_.get_total_mem_size(); }
   int64_t get_sys_var_mem_size() const { return base_sys_var_alloc_.total(); }
-  ObPartitionHitInfo &partition_hit() { return partition_hit_; } // 和上面的set_partition_hit没有任何关系
+  // no relationship with function set_partition_hit(const bool is_hit) above.
+  ObPartitionHitInfo &partition_hit() { return partition_hit_; }
   bool get_err_final_partition_hit(int err_ret)
   {
     bool is_partition_hit = partition_hit().get_bool();