Remove cmake warning configuration （August）

src/clog/ob_log_engine.h

@@ -435,7 +435,7 @@ public:
   int broadcast_info(const common::ObMemberList& mem_list, const common::ObPartitionKey& key,
       const common::ObReplicaType& replica_type, const uint64_t max_confirmed_log_id) override;
   int send_restore_check_rqst(const common::ObAddr& server, const int64_t dst_cluster_id,
-      const common::ObPartitionKey& key, const ObRestoreCheckType restore_type);
+      const common::ObPartitionKey& key, const ObRestoreCheckType restore_type) override;
   // confirmed_info msg is special that no need compare proposal_id
   int submit_confirmed_info(const share::ObCascadMemberList& mem_list, const common::ObPartitionKey& key,
       const uint64_t log_id, const ObConfirmedInfo& confirmed_info, const bool batch_committed) override;
@@ -476,7 +476,7 @@ public:
   int get_remote_mc_ctx_array(
       const common::ObAddr& server, const common::ObPartitionArray& partition_array, McCtxArray& mc_ctx_array);
   int send_query_restore_end_id_resp(const common::ObAddr& server, const int64_t cluster_id,
-      const common::ObPartitionKey& partition_key, const uint64_t last_restore_log_id);
+      const common::ObPartitionKey& partition_key, const uint64_t last_restore_log_id) override;
   int update_min_using_file_id();
   uint32_t get_clog_min_using_file_id() const override;
   uint32_t get_clog_min_file_id() const override;

src/clog/ob_log_membership_mgr_V2.h

@@ -115,7 +115,7 @@ public:
       const int64_t new_quorum, obrpc::ObMCLogInfo& log_info) override;
   virtual int64_t get_replica_num() const override;
   virtual common::ObReplicaType get_replica_type() const override;
-  virtual bool is_single_member_mode() const
+  virtual bool is_single_member_mode() const override
   {
     return (1 == replica_num_);
   }

src/clog/ob_log_sliding_window.h

@@ -542,7 +542,7 @@ private:
   int try_freeze_aggre_buffer_(const uint64_t log_id);
   int submit_freeze_aggre_buffer_task_(const uint64_t log_id);
   int submit_aggre_log_(ObAggreBuffer* buffer, const uint64_t log_id, const int64_t submit_timestamp);
-  int try_update_submit_timestamp(const int64_t base_ts);
+  int try_update_submit_timestamp(const int64_t base_ts) override;
   bool is_confirm_match_(const uint64_t log_id, const int64_t log_data_checksum, const int64_t log_epoch_id,
       const int64_t log_submit_timestamp, const int64_t confirmed_info_data_checksum,
       const int64_t confirmed_info_epoch_id, const int64_t confirmed_info_submit_timestamp);

src/clog/ob_partition_log_service.h

@@ -555,7 +555,7 @@ public:
       const ObProposalID& ms_proposal_id) override;
   virtual int fake_receive_log(const ObAddr& server, const uint64_t log_id, const ObProposalID& proposal_id) override;
   virtual int process_restore_check_req(
-      const common::ObAddr& server, const int64_t cluster_id, const ObRestoreCheckType restore_type);
+      const common::ObAddr& server, const int64_t cluster_id, const ObRestoreCheckType restore_type) override;
   virtual int get_log(const common::ObAddr& server, const uint64_t log_id, const int64_t log_num,
       const ObFetchLogType fetch_type, const common::ObProposalID& proposal_id, const int64_t cluster_id,
       const common::ObReplicaType replica_type, const int64_t network_limit,
@@ -790,7 +790,7 @@ private:
   int response_sliding_window_info_(const common::ObAddr& server, const bool is_leader);
   int process_replica_type_change_();
   int process_reject_msg(
-      const common::ObAddr& server, const int64_t cluster_id, const int32_t msg_type, const int64_t timestamp);
+      const common::ObAddr& server, const int64_t cluster_id, const int32_t msg_type, const int64_t timestamp) override;
   int process_reregister_msg(
       const common::ObAddr& src_server, const share::ObCascadMember& new_leader, const int64_t send_ts) override;
   int process_restore_alive_msg(const common::ObAddr& server, const uint64_t start_log_id) override;

src/observer/mysql/obmp_query.h

@@ -45,14 +45,14 @@ public:
   virtual ~ObMPQuery();
 
 public:
-  virtual void disconnect();
-  virtual void update_last_pkt_pos()
+  virtual void disconnect() override;
+  virtual void update_last_pkt_pos() override
   {
     if (NULL != ez_buf_) {
       comp_context_.update_last_pkt_pos(ez_buf_->last);
     }
   }
-  virtual int response_packet(obmysql::ObMySQLPacket& pkt)
+  virtual int response_packet(obmysql::ObMySQLPacket& pkt) override
   {
     return ObMPBase::response_packet(pkt);
   }
@@ -60,19 +60,19 @@ public:
   {
     return ObMPBase::flush_buffer(is_last);
   }
-  virtual int send_error_packet(int err, const char* errmsg, bool is_partition_hit = true, void* extra_err_info = NULL)
+  virtual int send_error_packet(int err, const char* errmsg, bool is_partition_hit = true, void* extra_err_info = NULL) override
   {
     return ObMPBase::send_error_packet(err, errmsg, is_partition_hit, extra_err_info);
   }
-  virtual int send_ok_packet(sql::ObSQLSessionInfo& session, ObOKPParam& ok_param)
+  virtual int send_ok_packet(sql::ObSQLSessionInfo& session, ObOKPParam& ok_param) override
   {
     return ObMPBase::send_ok_packet(session, ok_param);
   }
-  virtual int send_eof_packet(const sql::ObSQLSessionInfo& session, const ObMySQLResultSet& result)
+  virtual int send_eof_packet(const sql::ObSQLSessionInfo& session, const ObMySQLResultSet& result) override
   {
     return ObMPBase::send_eof_packet(session, result);
   }
-  virtual bool need_send_extra_ok_packet()
+  virtual bool need_send_extra_ok_packet() override
   {
     return OB_NOT_NULL(get_conn()) && get_conn()->need_send_extra_ok_packet();
   }
@@ -103,11 +103,11 @@ public:
   }
 
 protected:
-  int process();
-  int deserialize();
+  int process() override;
+  int deserialize() override;
   int check_readonly_stmt(ObMySQLResultSet& result);
   int is_readonly_stmt(ObMySQLResultSet& result, bool& is_readonly);
-  virtual int after_process();
+  virtual int after_process() override;
 
 private:
   int register_callback_with_async(ObQueryExecCtx& query_ctx);
@@ -119,7 +119,7 @@ private:
   int process_single_stmt(const sql::ObMultiStmtItem& multi_stmt_item, sql::ObSQLSessionInfo& session,
       bool has_more_result, bool force_sync_resp, bool& async_resp_used, bool& need_disconnect);
 
-  virtual int before_response()
+  virtual int before_response() override
   {
     return OB_SUCCESS;
   }

src/observer/mysql/obmp_stmt_execute.h

@@ -73,42 +73,42 @@ public:
   }
 
 protected:
-  virtual int deserialize()
+  virtual int deserialize() override
   {
     return common::OB_SUCCESS;
   }
-  virtual int process();
-  virtual void disconnect()
+  virtual int process() override;
+  virtual void disconnect() override
   {
     ObMPBase::disconnect();
   }
-  virtual void update_last_pkt_pos()
+  virtual void update_last_pkt_pos() override
   {
     if (NULL != ez_buf_) {
       comp_context_.update_last_pkt_pos(ez_buf_->last);
     }
   }
-  virtual int send_error_packet(int err, const char* errmsg, bool is_partition_hit = true, void* extra_err_info = NULL)
+  virtual int send_error_packet(int err, const char* errmsg, bool is_partition_hit = true, void* extra_err_info = NULL) override
   {
     return ObMPBase::send_error_packet(err, errmsg, is_partition_hit, extra_err_info);
   }
-  virtual int send_ok_packet(sql::ObSQLSessionInfo& session, ObOKPParam& ok_param)
+  virtual int send_ok_packet(sql::ObSQLSessionInfo& session, ObOKPParam& ok_param) override
   {
     return ObMPBase::send_ok_packet(session, ok_param);
   }
-  virtual int send_eof_packet(const sql::ObSQLSessionInfo& session, const ObMySQLResultSet& result)
+  virtual int send_eof_packet(const sql::ObSQLSessionInfo& session, const ObMySQLResultSet& result) override
   {
     return ObMPBase::send_eof_packet(session, result);
   }
-  virtual bool need_send_extra_ok_packet()
+  virtual bool need_send_extra_ok_packet() override
   {
     return OB_NOT_NULL(get_conn()) && get_conn()->need_send_extra_ok_packet();
   }
-  virtual int response_packet(obmysql::ObMySQLPacket& pkt)
+  virtual int response_packet(obmysql::ObMySQLPacket& pkt) override
   {
     return ObMPBase::response_packet(pkt);
   }
-  virtual int after_process()
+  virtual int after_process() override
   {
     return ObMPBase::after_process();
   }
@@ -153,11 +153,11 @@ private:
       const common::ObTimeZoneInfo* tz_info, sql::TypeInfo* type_info, sql::TypeInfo* dst_type_info, ObObjParam& param);
   int decode_type_info(const char*& buf, sql::TypeInfo& type_info);
 
-  virtual int before_response()
+  virtual int before_response() override
   {
     return OB_SUCCESS;
   }
-  virtual int before_process();
+  virtual int before_process() override;
   void record_stat(const sql::stmt::StmtType type, const int64_t end_time) const;
 
   // copy or convert string, resove %extra_buf_len before result string.

src/observer/mysql/obmp_stmt_prepare.h

@@ -61,37 +61,37 @@ public:
   }
 
 protected:
-  virtual int deserialize();
+  virtual int deserialize() override;
   virtual int before_process() override;
-  virtual int process();
+  virtual int process() override;
 
-  virtual void disconnect()
+  virtual void disconnect() override
   {
     ObMPBase::disconnect();
   }
-  virtual void update_last_pkt_pos()
+  virtual void update_last_pkt_pos() override
   {
     if (NULL != ez_buf_) {
       comp_context_.update_last_pkt_pos(ez_buf_->last);
     }
   }
-  virtual int send_error_packet(int err, const char* errmsg, bool is_partition_hit = true, void* extra_err_info = NULL)
+  virtual int send_error_packet(int err, const char* errmsg, bool is_partition_hit = true, void* extra_err_info = NULL) override
   {
     return ObMPBase::send_error_packet(err, errmsg, is_partition_hit, extra_err_info);
   }
-  virtual int send_ok_packet(sql::ObSQLSessionInfo& session, ObOKPParam& ok_param)
+  virtual int send_ok_packet(sql::ObSQLSessionInfo& session, ObOKPParam& ok_param) override
   {
     return ObMPBase::send_ok_packet(session, ok_param);
   }
-  virtual int send_eof_packet(const sql::ObSQLSessionInfo& session, const ObMySQLResultSet& result)
+  virtual int send_eof_packet(const sql::ObSQLSessionInfo& session, const ObMySQLResultSet& result) override
   {
     return ObMPBase::send_eof_packet(session, result);
   }
-  virtual int response_packet(obmysql::ObMySQLPacket& pkt)
+  virtual int response_packet(obmysql::ObMySQLPacket& pkt) override
   {
     return ObMPBase::response_packet(pkt);
   }
-  virtual bool need_send_extra_ok_packet()
+  virtual bool need_send_extra_ok_packet() override
   {
     return OB_NOT_NULL(get_conn()) && get_conn()->need_send_extra_ok_packet();
   }

src/observer/ob_inner_sql_connection.cpp

@@ -58,7 +58,7 @@ public:
   virtual ~ObSqlQueryExecutor()
   {}
 
-  virtual int execute(sql::ObSql& engine, sql::ObSqlCtx& ctx, sql::ObResultSet& res)
+  virtual int execute(sql::ObSql& engine, sql::ObSqlCtx& ctx, sql::ObResultSet& res) override
   {
     observer::ObReqTimeGuard req_timeinfo_guard;
     int ret = OB_SUCCESS;

src/observer/virtual_table/ob_all_virtual_session_event.h

@@ -80,7 +80,7 @@ public:
   }
 
 protected:
-  virtual int get_all_diag_info();
+  virtual int get_all_diag_info() override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObAllVirtualSessionEventI1);

src/observer/virtual_table/ob_all_virtual_session_stat.h

@@ -72,7 +72,7 @@ public:
   }
 
 protected:
-  virtual int get_all_diag_info();
+  virtual int get_all_diag_info() override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObAllVirtualSessionStatI1);

src/observer/virtual_table/ob_all_virtual_session_wait.h

@@ -83,7 +83,7 @@ public:
   }
 
 protected:
-  virtual int get_all_diag_info();
+  virtual int get_all_diag_info() override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObAllVirtualSessionWaitI1);

src/observer/virtual_table/ob_all_virtual_session_wait_history.h

@@ -83,7 +83,7 @@ public:
   }
 
 protected:
-  virtual int get_all_diag_info();
+  virtual int get_all_diag_info() override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObAllVirtualSessionWaitHistoryI1);

src/observer/virtual_table/ob_all_virtual_sys_event.h

@@ -76,7 +76,7 @@ public:
   }
 
 protected:
-  virtual int get_all_diag_info();
+  virtual int get_all_diag_info() override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObAllVirtualSysEventI1);

src/observer/virtual_table/ob_all_virtual_sys_stat.h

@@ -76,7 +76,7 @@ public:
   }
 
 protected:
-  virtual int get_all_diag_info();
+  virtual int get_all_diag_info() override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObAllVirtualSysStatI1);

src/observer/virtual_table/ob_iterate_virtual_table.h

@@ -37,7 +37,7 @@ public:
 private:
   virtual int init_non_exist_map_item(MapItem& item, const share::schema::ObColumnSchemaV2& col) override;
 
-  virtual int setup_inital_rowkey_condition(common::ObSqlString& cols, common::ObSqlString& vals);
+  virtual int setup_inital_rowkey_condition(common::ObSqlString& cols, common::ObSqlString& vals) override;
   virtual int add_extra_condition(common::ObSqlString& sql) override;
 
   bool check_tenant_in_range(const uint64_t tenant_id, const common::ObNewRange& range);

src/rootserver/ob_server_recovery_machine.h

@@ -274,7 +274,7 @@ public:
 
 public:
   virtual void run3() override;
-  virtual int blocking_run()
+  virtual int blocking_run() override
   {
     BLOCKING_RUN_IMPLEMENT();
   }
@@ -289,7 +289,7 @@ public:
   int on_check_pg_recovery_finished(const common::ObAddr& server, const int ret_code);
   int update_file_recovery_status(const common::ObAddr& server, const common::ObAddr& dest_server,
       const uint64_t tenant_id, const int64_t file_id, FileRecoveryStatus pre_status, FileRecoveryStatus cur_status);
-  void stop();
+  void stop() override;
 
 private:
   // Machine const

src/rootserver/ob_zone_unit_provider.h

@@ -65,8 +65,8 @@ public:
   {
     zu_ = my_zu;
   }
-  virtual const share::ObUnitInfo* at(int64_t idx) const;
-  virtual int64_t count() const;
+  virtual const share::ObUnitInfo* at(int64_t idx) const override;
+  virtual int64_t count() const override;
   virtual int get_target_unit_idx(const int64_t unit_offset, common::hash::ObHashSet<int64_t>& unit_set,
       const bool is_primary_partition, int64_t& unit_idx) const override;
   virtual int update_tg_pg_count(const int64_t unit_idx, const bool is_primary_partition) override;
@@ -141,8 +141,8 @@ public:
   {
     all_unit_ = all_unit;
   }
-  virtual const share::ObUnitInfo* at(int64_t idx) const;
-  virtual int64_t count() const;
+  virtual const share::ObUnitInfo* at(int64_t idx) const override;
+  virtual int64_t count() const override;
   virtual int get_target_unit_idx(const int64_t unit_offset, common::hash::ObHashSet<int64_t>& unit_set,
       const bool is_primary_partition, int64_t& unit_idx) const override;
   virtual int update_tg_pg_count(const int64_t unit_idx, const bool is_primary_partition) override;
@@ -161,7 +161,7 @@ public:
   {}
   virtual ~ObZoneLogonlyUnitProvider()
   {}
-  virtual int find_zone(const common::ObZone& zone, const ObZoneUnitAdaptor*& zua);
+  virtual int find_zone(const common::ObZone& zone, const ObZoneUnitAdaptor*& zua) override;
   virtual int get_all_zone_units(ZoneUnitArray& zone_unit) const override;
   virtual int get_all_ptr_zone_units(ZoneUnitPtrArray& zone_unit_ptr) const override;
   virtual bool exist(const ObZone& zone, const uint64_t unit_id) const override;
@@ -184,7 +184,7 @@ public:
   {}
   virtual int get_all_zone_units(ZoneUnitArray& zone_unit) const override;
   virtual int get_all_ptr_zone_units(ZoneUnitPtrArray& zone_unit_ptr) const override;
-  virtual int find_zone(const common::ObZone& zone, const ObZoneUnitAdaptor*& zua);
+  virtual int find_zone(const common::ObZone& zone, const ObZoneUnitAdaptor*& zua) override;
 
 private:
   const ZoneUnitArray& all_zone_units_;
@@ -201,7 +201,7 @@ public:
   {}
   virtual ~ObAllZoneUnitsProvider()
   {}
-  virtual int find_zone(const common::ObZone& zone, const ObZoneUnitAdaptor*& zua);
+  virtual int find_zone(const common::ObZone& zone, const ObZoneUnitAdaptor*& zua) override;
   virtual int get_all_zone_units(ZoneUnitArray& zone_unit) const override;
   virtual int get_all_ptr_zone_units(ZoneUnitPtrArray& zone_unit_ptr) const override;
 

src/share/partition_table/ob_partition_table_proxy.h

@@ -156,7 +156,7 @@ public:
   {}
   virtual ~ObKVPartitionTableProxy()
   {}
-  virtual int reset()
+  virtual int reset() override
   {
     is_loaded_ = false;
     implicit_trans_started_ = false;
@@ -170,7 +170,7 @@ public:
 
   virtual int fetch_partition_info(const bool lock_replica, const uint64_t table_id, const int64_t partition_id,
       const bool filter_flag_replica, ObPartitionInfo& partition_info, const bool need_fetch_faillist = false,
-      const int64_t cluster_id = common::OB_INVALID_ID);
+      const int64_t cluster_id = common::OB_INVALID_ID) override;
 
   virtual int fetch_partition_infos(const uint64_t tenant_id, const uint64_t start_table_id,
       const int64_t start_partition_id, const bool filter_flag_replica, int64_t& max_fetch_count,
@@ -179,36 +179,36 @@ public:
 
   virtual int fetch_partition_infos_pt(const uint64_t pt_table_id, const int64_t pt_partition_id,
       const uint64_t start_table_id, const int64_t start_partition_id, int64_t& max_fetch_count,
-      common::ObIArray<ObPartitionInfo>& partition_infos, const bool need_fetch_faillist = false);
+      common::ObIArray<ObPartitionInfo>& partition_infos, const bool need_fetch_faillist = false) override;
 
   virtual int batch_fetch_partition_infos(const common::ObIArray<common::ObPartitionKey>& keys,
       common::ObIAllocator& allocator, common::ObArray<ObPartitionInfo*>& partitions,
       const int64_t cluster_id = common::OB_INVALID_ID) override;
 
-  virtual int update_replica(const ObPartitionReplica& replica, const bool replace);
-  virtual int update_replica(const ObPartitionReplica& replica);
+  virtual int update_replica(const ObPartitionReplica& replica, const bool replace) override;
+  virtual int update_replica(const ObPartitionReplica& replica) override;
   virtual int batch_report_with_optimization(
-      const common::ObIArray<ObPartitionReplica>& replicas, const bool with_role);
+      const common::ObIArray<ObPartitionReplica>& replicas, const bool with_role) override;
   virtual int batch_report_partition_role(
-      const common::ObIArray<share::ObPartitionReplica>& tasks, const common::ObRole new_role);
+      const common::ObIArray<share::ObPartitionReplica>& tasks, const common::ObRole new_role) override;
 
-  virtual int set_to_follower_role(const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server);
+  virtual int set_to_follower_role(const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server) override;
 
-  virtual int remove(const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server);
+  virtual int remove(const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server) override;
 
   virtual int set_unit_id(
-      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const uint64_t unit_id);
+      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const uint64_t unit_id) override;
 
-  virtual int set_original_leader(const uint64_t table_id, const int64_t partition_id, const bool is_original_leader);
+  virtual int set_original_leader(const uint64_t table_id, const int64_t partition_id, const bool is_original_leader) override;
 
   virtual int update_rebuild_flag(
-      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const bool rebuild);
+      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const bool rebuild) override;
 
   virtual int update_fail_list(const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server,
-      const ObPartitionReplica::FailList& fail_list);
+      const ObPartitionReplica::FailList& fail_list) override;
 
   virtual int update_replica_status(
-      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const ObReplicaStatus status);
+      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const ObReplicaStatus status) override;
 
   static int fill_dml_splicer_for_update(const ObPartitionReplica& replica, ObDMLSqlSplicer& dml_splicer);
 
@@ -240,7 +240,7 @@ public:
 
   virtual int fetch_partition_info(const bool lock_replica, const uint64_t table_id, const int64_t partition_id,
       const bool filter_flag_replica, ObPartitionInfo& partition_info, const bool need_fetch_faillist = false,
-      const int64_t cluster_id = common::OB_INVALID_ID);
+      const int64_t cluster_id = common::OB_INVALID_ID) override;
 
   virtual int fetch_partition_infos(const uint64_t tenant_id, const uint64_t start_table_id,
       const int64_t start_partition_id, const bool filter_flag_replica, int64_t& max_fetch_count,
@@ -249,35 +249,35 @@ public:
 
   virtual int fetch_partition_infos_pt(const uint64_t pt_table_id, const int64_t pt_partition_id,
       const uint64_t start_table_id, const int64_t start_partition_id, int64_t& max_fetch_count,
-      common::ObIArray<ObPartitionInfo>& partition_infos, const bool need_fetch_faillist = false);
+      common::ObIArray<ObPartitionInfo>& partition_infos, const bool need_fetch_faillist = false) override;
 
   virtual int batch_fetch_partition_infos(const common::ObIArray<common::ObPartitionKey>& keys,
       common::ObIAllocator& allocator, common::ObArray<ObPartitionInfo*>& partitions,
       const int64_t cluster_id = common::OB_INVALID_ID) override;
 
-  virtual int update_replica(const ObPartitionReplica& replica, const bool replace);
-  virtual int update_replica(const ObPartitionReplica& replica);
+  virtual int update_replica(const ObPartitionReplica& replica, const bool replace) override;
+  virtual int update_replica(const ObPartitionReplica& replica) override;
   virtual int batch_report_with_optimization(
-      const common::ObIArray<ObPartitionReplica>& replicas, const bool with_role);
+      const common::ObIArray<ObPartitionReplica>& replicas, const bool with_role) override;
   virtual int batch_report_partition_role(
-      const common::ObIArray<share::ObPartitionReplica>& tasks, const common::ObRole new_role);
+      const common::ObIArray<share::ObPartitionReplica>& tasks, const common::ObRole new_role) override;
 
-  virtual int set_to_follower_role(const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server);
+  virtual int set_to_follower_role(const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server) override;
 
-  virtual int remove(const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server);
+  virtual int remove(const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server) override;
 
   virtual int set_unit_id(
-      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const uint64_t unit_id);
+      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const uint64_t unit_id) override;
 
   virtual int update_rebuild_flag(
-      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const bool rebuild);
+      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const bool rebuild) override;
 
-  virtual int set_original_leader(const uint64_t table_id, const int64_t partition_id, const bool is_original_leader);
+  virtual int set_original_leader(const uint64_t table_id, const int64_t partition_id, const bool is_original_leader) override;
   virtual int update_fail_list(const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server,
-      const ObPartitionReplica::FailList& fail_list);
+      const ObPartitionReplica::FailList& fail_list) override;
 
   virtual int update_replica_status(
-      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const ObReplicaStatus status);
+      const uint64_t table_id, const int64_t partition_id, const common::ObAddr& server, const ObReplicaStatus status) override;
 
   // batch update data_version of replicas which been creating right now.
   // Note: only support __all_tenant_meta_table partitions

src/sql/dtl/ob_dtl_basic_channel.h

@@ -343,7 +343,7 @@ public:
   explicit ObDtlBasicChannel(const uint64_t tenant_id, const uint64_t id, const common::ObAddr& peer);
   virtual ~ObDtlBasicChannel();
 
-  virtual DtlChannelType get_channel_type()
+  virtual DtlChannelType get_channel_type() override
   {
     return DtlChannelType::BASIC_CHANNEL;
   }
@@ -368,7 +368,7 @@ public:
   virtual int send(
       const ObDtlMsg& msg, int64_t timeout_ts, ObEvalCtx* eval_ctx = nullptr, bool is_eof = false) override;
   virtual int feedup(ObDtlLinkedBuffer*& buffer) override;
-  virtual int attach(ObDtlLinkedBuffer*& linked_buffer, bool is_first_buffer_cached = false);
+  virtual int attach(ObDtlLinkedBuffer*& linked_buffer, bool is_first_buffer_cached = false) override;
   // don't call send&flush in different threads.
   virtual int flush(bool wait = true, bool wait_response = true) override;
 
@@ -397,8 +397,8 @@ public:
   int unblock_on_decrease_size(int64_t size);
   bool belong_to_receive_data();
   bool belong_to_transmit_data();
-  virtual int clear_response_block();
-  virtual int wait_response();
+  virtual int clear_response_block() override;
+  virtual int wait_response() override;
   void inc_send_buffer_cnt()
   {
     ++send_buffer_cnt_;
@@ -425,12 +425,12 @@ public:
   }
 
   int get_processed_buffer(int64_t timeout);
-  virtual int clean_recv_list();
+  virtual int clean_recv_list() override;
   void clean_broadcast_buffer();
   bool has_less_buffer_cnt();
   int push_back_send_list(ObDtlLinkedBuffer* buffer);
 
-  void set_dfc_idx(int64_t idx)
+  void set_dfc_idx(int64_t idx) override
   {
     dfc_idx_ = idx;
   }
@@ -461,7 +461,7 @@ protected:
     return &msg_response_;
   }
 
-  OB_INLINE virtual bool has_msg()
+  OB_INLINE virtual bool has_msg() override
   {
     return recv_buffer_cnt_ > processed_buffer_cnt_;
   }

src/sql/dtl/ob_dtl_channel_loop.h

@@ -109,7 +109,7 @@ private:
 
 public:
   int unblock_channels(int64_t data_channel_idx);
-  void add_last_data_list(ObDtlChannel* ch);
+  void add_last_data_list(ObDtlChannel* ch) override;
   virtual void remove_data_list(ObDtlChannel* ch, bool force) override;
   void add(ObDtlChannel* prev, ObDtlChannel* node, ObDtlChannel* next);
   virtual void set_first_no_data(ObDtlChannel* ch) override

src/sql/dtl/ob_dtl_local_channel.h

@@ -37,7 +37,7 @@ public:
   explicit ObDtlLocalChannel(const uint64_t tenant_id, const uint64_t id, const common::ObAddr& peer);
   virtual ~ObDtlLocalChannel();
 
-  virtual DtlChannelType get_channel_type()
+  virtual DtlChannelType get_channel_type() override
   {
     return DtlChannelType::LOCAL_CHANNEL;
   }
@@ -46,7 +46,7 @@ public:
   virtual void destroy();
 
   virtual int feedup(ObDtlLinkedBuffer*& buffer) override;
-  virtual int send_message(ObDtlLinkedBuffer*& buf);
+  virtual int send_message(ObDtlLinkedBuffer*& buf) override;
 
 private:
   int send_shared_message(ObDtlLinkedBuffer*& buf);

src/sql/dtl/ob_dtl_rpc_channel.h

@@ -92,7 +92,7 @@ public:
   explicit ObDtlRpcChannel(const uint64_t tenant_id, const uint64_t id, const common::ObAddr& peer);
   virtual ~ObDtlRpcChannel();
 
-  virtual DtlChannelType get_channel_type()
+  virtual DtlChannelType get_channel_type() override
   {
     return DtlChannelType::RPC_CHANNEL;
   }
@@ -101,7 +101,7 @@ public:
   virtual void destroy();
 
   virtual int feedup(ObDtlLinkedBuffer*& buffer) override;
-  virtual int send_message(ObDtlLinkedBuffer*& buf);
+  virtual int send_message(ObDtlLinkedBuffer*& buf) override;
 };
 
 }  // namespace dtl

src/sql/engine/aggregate/ob_groupby_op.h

@@ -53,7 +53,7 @@ public:
   }
 
   virtual int inner_open() override;
-  virtual int inner_get_next_row() = 0;
+  virtual int inner_get_next_row() override = 0;
   virtual int rescan() override;
   virtual int switch_iterator() override;
   virtual int inner_close() override;

src/sql/engine/connect_by/ob_nested_loop_connect_by.h

@@ -134,7 +134,7 @@ public:
     virtual ~ObConnectByCtx()
     {}
     void reset();
-    virtual void destroy()
+    virtual void destroy() override
     {
       connect_by_pump_.~ObConnectByPump();  // must be call
       ObConnectByBaseCtx::destroy();

src/sql/engine/dml/ob_table_modify_op.h

@@ -169,7 +169,7 @@ public:
   {}
   virtual ~ObTableModifyOpInput()
   {}
-  virtual void reset()
+  virtual void reset() override
   {
     location_idx_ = common::OB_INVALID_INDEX;
     part_infos_.reset();
@@ -187,7 +187,7 @@ public:
    * @brief set allocator which is used for deserialize, but not all objects will use allocator
    * while deserializing, so you can override it if you need.
    */
-  virtual void set_deserialize_allocator(common::ObIAllocator* allocator)
+  virtual void set_deserialize_allocator(common::ObIAllocator* allocator) override
   {
     part_infos_.set_allocator(allocator);
   }
@@ -351,9 +351,9 @@ public:
   }
 
 protected:
-  OperatorOpenOrder get_operator_open_order() const;
-  virtual int inner_open();
-  virtual int inner_close();
+  OperatorOpenOrder get_operator_open_order() const override;
+  virtual int inner_open() override;
+  virtual int inner_close() override;
 
   // project expressions to old style row, allocate cells from ctx_.get_allocator() if needed.
   int project_row(ObExpr* const* exprs, const int64_t cnt, common::ObNewRow& row) const;

src/sql/engine/expr/ob_expr_calc_partition_id.h

@@ -60,7 +60,7 @@ public:
   explicit ObExprCalcPartitionId(common::ObIAllocator& alloc);
   virtual ~ObExprCalcPartitionId();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types_array, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types_array, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_no_partition_location(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
   static int calc_partition_level_one(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);

src/sql/engine/expr/ob_expr_calc_urowid.h

@@ -22,11 +22,11 @@ public:
   explicit ObExprCalcURowID(common::ObIAllocator& alloc);
   virtual ~ObExprCalcURowID();
 
-  virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types_statck, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+  virtual int calc_result_typeN(ObExprResType& type, ObExprResType* types_statck, int64_t param_num,
+      common::ObExprTypeCtx& type_ctx) const override;
 
-  virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* obj_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_resultN(common::ObObj& result, const common::ObObj* obj_stack, int64_t param_num,
+      common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_concat.h

@@ -23,9 +23,9 @@ public:
   virtual ~ObExprConcat();
 
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
       common::ObIAllocator* allocator, const common::ObObjType result_type, bool is_oracle_mode);
   // Check result length with %max_result_len (if %max_result_len greater than zero)

src/sql/engine/expr/ob_expr_concat_ws.h

@@ -22,9 +22,9 @@ public:
   explicit ObExprConcatWs(common::ObIAllocator& alloc);
   virtual ~ObExprConcatWs();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   // connect two strings by separator
   static int concat_ws(
       const common::ObString obj1, const common::ObString obj2, const int64_t buf_len, char** string_buf, int64_t& pos);

src/sql/engine/expr/ob_expr_div.h

@@ -24,9 +24,9 @@ public:
   virtual ~ObExprDiv()
   {}
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& left, const common::ObObj& right, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj& left, const common::ObObj& right, common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& res, const common::ObObj& obj1, const common::ObObj& obj2,
       common::ObIAllocator* allocator, common::ObScale calc_scale);
   static int calc_for_avg(common::ObObj& res, const common::ObObj& obj1, const common::ObObj& obj2,

src/sql/engine/expr/ob_expr_format.h

@@ -38,9 +38,9 @@ public:
   explicit ObExprFormat(common::ObIAllocator& alloc);
   virtual ~ObExprFormat();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_array, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_resultN(common::ObObj& result, const common::ObObj* objs_array, int64_t param_num,
+      common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_format_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
 

src/sql/engine/expr/ob_expr_greater_equal.h

@@ -22,10 +22,10 @@ public:
   ObExprGreaterEqual();
   explicit ObExprGreaterEqual(common::ObIAllocator& alloc);
   virtual ~ObExprGreaterEqual(){};
-  virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
-  virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result2(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
+  virtual int calc_resultN(common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num,
+      common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override
   {

src/sql/engine/expr/ob_expr_greater_than.h

@@ -24,10 +24,10 @@ public:
   ObExprGreaterThan();
   explicit ObExprGreaterThan(common::ObIAllocator& alloc);
   virtual ~ObExprGreaterThan(){};
-  virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
-  virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result2(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
+  virtual int calc_resultN(common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num,
+      common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override
   {

src/sql/engine/expr/ob_expr_hex.h

@@ -21,9 +21,9 @@ class ObExprHex : public ObStringExprOperator {
 public:
   explicit ObExprHex(common::ObIAllocator& alloc);
   virtual ~ObExprHex();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const;
+  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj& text, common::ObCastCtx& cast_ctx);
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_initcap.h

@@ -22,8 +22,10 @@ class ObExprInitcap : public ObStringExprOperator {
 public:
   explicit ObExprInitcap(common::ObIAllocator& alloc);
   virtual ~ObExprInitcap();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& text_obj, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type1(
+      ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result1(
+      common::ObObj& result, const common::ObObj& text_obj, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int initcap_string(const common::ObString& text, const common::ObCollationType cs_type,
       common::ObIAllocator* allocator, common::ObString& res_str);

src/sql/engine/expr/ob_expr_int2ip.h

@@ -21,9 +21,9 @@ class ObExprInt2ip : public ObStringExprOperator {
 public:
   explicit ObExprInt2ip(common::ObIAllocator& alloc);
   virtual ~ObExprInt2ip();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const;
+  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj& text, common::ObExprStringBuf& string_buf);
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int int2ip_varchar(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 

src/sql/engine/expr/ob_expr_int_div.h

@@ -21,9 +21,9 @@ public:
   explicit ObExprIntDiv(common::ObIAllocator& alloc);
   virtual ~ObExprIntDiv(){};
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_result2(
-      common::ObObj& res, const common::ObObj& ojb1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& res, const common::ObObj& ojb1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& res, const common::ObObj& ojb1, const common::ObObj& obj2,
       common::ObIAllocator* allocator, common::ObScale scale);
   static int div_int_int(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);

src/sql/engine/expr/ob_expr_interval.h

@@ -30,7 +30,7 @@ public:
   virtual ~ObExprInterval()
   {}
 
-  virtual int assign(const ObExprOperator& other);
+  virtual int assign(const ObExprOperator& other) override;
 
   OB_INLINE void set_use_binary_search(bool use_binary_search)
   {

src/sql/engine/expr/ob_expr_ip2int.h

@@ -21,9 +21,9 @@ class ObExprIp2int : public ObFuncExprOperator {
 public:
   explicit ObExprIp2int(common::ObIAllocator& alloc);
   virtual ~ObExprIp2int();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const;
+  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx);
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int ip2int_varchar(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 

src/sql/engine/expr/ob_expr_is.h

@@ -59,9 +59,9 @@ public:
   virtual ~ObExprIs(){};
 
   virtual int calc_with_null(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
-      const common::ObObj& obj3, common::ObCastCtx& cast_ctx) const;
+      const common::ObObj& obj3, common::ObCastCtx& cast_ctx) const override;
   virtual int calc_with_int(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObCastCtx& cast_ctx) const;
+      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObCastCtx& cast_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_is_date_int_null(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
   static int calc_is_null(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
@@ -89,9 +89,9 @@ public:
   virtual ~ObExprIsNot(){};
 
   virtual int calc_with_null(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
-      const common::ObObj& obj3, common::ObCastCtx& cast_ctx) const;
+      const common::ObObj& obj3, common::ObCastCtx& cast_ctx) const override;
   virtual int calc_with_int(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObCastCtx& cast_ctx) const;
+      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObCastCtx& cast_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_is_not_null(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
   static int int_is_not_true(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);

src/sql/engine/expr/ob_expr_is_serving_tenant.h

@@ -23,9 +23,9 @@ public:
   virtual ~ObExprIsServingTenant();
 
   virtual int calc_result_type3(ObExprResType& type, ObExprResType& type1, ObExprResType& type2, ObExprResType& type3,
-      common::ObExprTypeCtx& type_ctx) const;
+      common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_result3(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
-      const common::ObObj& obj3, common::ObExprCtx& expr_ctx) const;
+      const common::ObObj& obj3, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
   static int eval_is_serving_tenant(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);

src/sql/engine/expr/ob_expr_last_exec_id.h

@@ -19,8 +19,8 @@ class ObExprLastExecId : public ObStringExprOperator {
 public:
   explicit ObExprLastExecId(common::ObIAllocator& alloc);
   virtual ~ObExprLastExecId();
-  virtual int calc_result_type0(ObExprResType& type, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type0(ObExprResType& type, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const override;
   static int eval_last_exec_id(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_last_insert_id.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprLastInsertID(common::ObIAllocator& alloc);
   virtual ~ObExprLastInsertID();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types_array, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types_array, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_array, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs_array, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_last_trace_id.h

@@ -21,8 +21,8 @@ class ObExprLastTraceId : public ObStringExprOperator {
 public:
   explicit ObExprLastTraceId(common::ObIAllocator& alloc);
   virtual ~ObExprLastTraceId();
-  virtual int calc_result_type0(ObExprResType& type, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type0(ObExprResType& type, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const override;
   static int eval_last_trace_id(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_least.h

@@ -40,9 +40,9 @@ public:
       const char* name = N_LEAST);
   virtual ~ObExprBaseLeast();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types_stack, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types_stack, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num,
       const ObExprResType& expected_type, common::ObExprCtx& expr_ctx);
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;

src/sql/engine/expr/ob_expr_length.h

@@ -21,9 +21,9 @@ class ObExprLength : public ObFuncExprOperator {
 public:
   explicit ObExprLength(common::ObIAllocator& alloc);
   virtual ~ObExprLength();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const;
+  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx);
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_null(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
   static int calc_oracle_mode(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);

src/sql/engine/expr/ob_expr_lengthb.h

@@ -24,9 +24,9 @@ class ObExprLengthb : public ObFuncExprOperator {
 public:
   explicit ObExprLengthb(common::ObIAllocator& alloc);
   virtual ~ObExprLengthb();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const;
+  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx);
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_lengthb_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
 

src/sql/engine/expr/ob_expr_less_equal.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprLessEqual(common::ObIAllocator& alloc);
   virtual ~ObExprLessEqual(){};
   virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
       const common::ObCompareCtx& cmp_ctx, common::ObCastCtx& cast_ctx);
   static int calc_nocast(

src/sql/engine/expr/ob_expr_less_than.h

@@ -25,9 +25,9 @@ public:
   explicit ObExprLessThan(common::ObIAllocator& alloc);
   virtual ~ObExprLessThan(){};
   virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
       const common::ObCompareCtx& cmp_ctx, common::ObCastCtx& cast_ctx);
   static int calc_nocast(

src/sql/engine/expr/ob_expr_like.h

@@ -95,9 +95,9 @@ public:
   explicit ObExprLike(common::ObIAllocator& alloc);
   virtual ~ObExprLike();
   virtual int calc_result_type3(ObExprResType& type, ObExprResType& type1, ObExprResType& type2, ObExprResType& type3,
-      common::ObExprTypeCtx& type_ctx) const;
+      common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_result3(common::ObObj& result, const common::ObObj& obj, const common::ObObj& pattern,
-      const common::ObObj& escape, common::ObExprCtx& expr_ctx) const;
+      const common::ObObj& escape, common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& result, common::ObCollationType coll_type, const common::ObObj& obj,
       const common::ObObj& pattern, const common::ObObj& escape, common::ObExprCtx& expr_ctx,
       const bool is_going_optimization, const uint64_t like_id, const bool check_optimization);
@@ -105,7 +105,7 @@ public:
   static int calc_with_non_instr_mode(T& result, const common::ObCollationType coll_type,
       const common::ObCollationType escape_coll, const common::ObString& text_val, const common::ObString& pattern_val,
       const common::ObString& escape_val);
-  int assign(const ObExprOperator& other);
+  int assign(const ObExprOperator& other) override;
   OB_INLINE bool is_pattern_literal() const
   {
     return is_pattern_literal_;

src/sql/engine/expr/ob_expr_lnnvl.h

@@ -21,8 +21,8 @@ class ObExprFuncLnnvl : public ObFuncExprOperator {
 public:
   explicit ObExprFuncLnnvl(common::ObIAllocator& alloc);
   virtual ~ObExprFuncLnnvl();
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& input, common::ObExprCtx& expr_ctx) const;
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& input, common::ObExprCtx& expr_ctx) const override;
+  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
   static int eval_lnnvl(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);

src/sql/engine/expr/ob_expr_log10.h

@@ -21,8 +21,8 @@ class ObExprLog10 : public ObFuncExprOperator {
 public:
   explicit ObExprLog10(common::ObIAllocator& alloc);
   virtual ~ObExprLog10();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
 private:

src/sql/engine/expr/ob_expr_log2.h

@@ -21,8 +21,8 @@ class ObExprLog2 : public ObFuncExprOperator {
 public:
   explicit ObExprLog2(common::ObIAllocator& alloc);
   virtual ~ObExprLog2();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
 private:

src/sql/engine/expr/ob_expr_lower.h

@@ -55,8 +55,8 @@ public:
   virtual ~ObExprLower()
   {}
   virtual int calc(const common::ObCollationType cs_type, char* src, int32_t src_len, char* dest, int32_t det_len,
-      int32_t& out_len) const;
-  virtual int32_t get_case_mutiply(const common::ObCollationType cs_type) const;
+      int32_t& out_len) const override;
+  virtual int32_t get_case_mutiply(const common::ObCollationType cs_type) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_lower(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 
@@ -70,8 +70,8 @@ public:
   virtual ~ObExprUpper()
   {}
   virtual int calc(const common::ObCollationType cs_type, char* src, int32_t src_len, char* dest, int32_t det_len,
-      int32_t& out_len) const;
-  virtual int32_t get_case_mutiply(const common::ObCollationType cs_type) const;
+      int32_t& out_len) const override;
+  virtual int32_t get_case_mutiply(const common::ObCollationType cs_type) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_upper(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 
@@ -85,8 +85,8 @@ public:
   virtual ~ObExprNlsLower()
   {}
   virtual int calc(const common::ObCollationType cs_type, char* src, int32_t src_len, char* dest, int32_t det_len,
-      int32_t& out_len) const;
-  virtual int32_t get_case_mutiply(const common::ObCollationType cs_type) const;
+      int32_t& out_len) const override;
+  virtual int32_t get_case_mutiply(const common::ObCollationType cs_type) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_lower(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 
@@ -100,8 +100,8 @@ public:
   virtual ~ObExprNlsUpper()
   {}
   virtual int calc(const common::ObCollationType cs_type, char* src, int32_t src_len, char* dest, int32_t det_len,
-      int32_t& out_len) const;
-  virtual int32_t get_case_mutiply(const common::ObCollationType cs_type) const;
+      int32_t& out_len) const override;
+  virtual int32_t get_case_mutiply(const common::ObCollationType cs_type) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_upper(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 

src/sql/engine/expr/ob_expr_lrpad.h

@@ -100,7 +100,7 @@ public:
   virtual int calc_result3(common::ObObj& result, const common::ObObj& text, const common::ObObj& len,
       const common::ObObj& pad_text, common::ObExprCtx& expr_ctx) const override;
   // for engine 3.0
-  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const;
+  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_mysql_rpad_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res);
 
 private:
@@ -118,7 +118,7 @@ public:
   virtual int calc_resultN(common::ObObj& result, const common::ObObj* objs_array, int64_t param_num,
       common::ObExprCtx& expr_ctx) const override;
   // for engine 3.0
-  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const;
+  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_oracle_lpad_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res);
 
 private:
@@ -136,7 +136,7 @@ public:
   virtual int calc_resultN(common::ObObj& result, const common::ObObj* objs_array, int64_t param_num,
       common::ObExprCtx& expr_ctx) const override;
   // for engine 3.0
-  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const;
+  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_oracle_rpad_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res);
 
 private:

src/sql/engine/expr/ob_expr_md5.h

@@ -24,8 +24,8 @@ public:
   virtual ~ObExprMd5();
 
 public:
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& str, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& str_obj, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type1(ObExprResType& type, ObExprResType& str, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& str_obj, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_md5(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 

src/sql/engine/expr/ob_expr_minus.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprMinus(common::ObIAllocator& alloc, ObExprOperatorType type = T_OP_MINUS);
   virtual ~ObExprMinus(){};
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& left, const common::ObObj& right, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj& left, const common::ObObj& right, common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& res, const common::ObObj& ojb1, const common::ObObj& obj2,
       common::ObIAllocator* allocator, common::ObScale scale);
   static int calc(common::ObObj& res, const common::ObObj& ojb1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx,

src/sql/engine/expr/ob_expr_mod.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprMod(common::ObIAllocator& alloc);
   virtual ~ObExprMod(){};
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result2(
-      common::ObObj& res, const common::ObObj& ojb1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result2(common::ObObj& res, const common::ObObj& ojb1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& res, const common::ObObj& ojb1, const common::ObObj& obj2,
       common::ObIAllocator* allocator, common::ObScale scale);
 

src/sql/engine/expr/ob_expr_mul.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprMul(common::ObIAllocator& alloc, ObExprOperatorType type = T_OP_MUL);
   virtual ~ObExprMul(){};
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& left, const common::ObObj& right, common::ObExprCtx& expr_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result2(common::ObObj& result, const common::ObObj& left, const common::ObObj& right,
+      common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& res, const common::ObObj& ojb1, const common::ObObj& obj2,
       common::ObIAllocator* allocator, common::ObScale scale);
   static int calc(common::ObObj& res, const common::ObObj& ojb1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx,

src/sql/engine/expr/ob_expr_not_equal.h

@@ -24,15 +24,15 @@ public:
   ObExprNotEqual();
   explicit ObExprNotEqual(common::ObIAllocator& alloc);
   virtual ~ObExprNotEqual(){};
-  virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
-  virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result2(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
+  virtual int calc_resultN(common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num,
+      common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
       const common::ObCompareCtx& cmp_ctx, common::ObCastCtx& cast_ctx);
 
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override
   {

src/sql/engine/expr/ob_expr_random.h

@@ -36,9 +36,9 @@ public:
   explicit ObExprRandom(common::ObIAllocator& alloc);
   virtual ~ObExprRandom();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   inline void set_seed_const(bool is_seed_const);
 
   // engine 3.0

src/sql/engine/expr/ob_expr_regexp.h

@@ -25,12 +25,12 @@ public:
   explicit ObExprRegexp(common::ObIAllocator& alloc);
   virtual ~ObExprRegexp();
 
-  virtual int assign(const ObExprOperator& other);
+  virtual int assign(const ObExprOperator& other) override;
 
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& obj, const common::ObObj& pattern, common::ObExprCtx& expr_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result2(common::ObObj& result, const common::ObObj& obj, const common::ObObj& pattern,
+      common::ObExprCtx& expr_ctx) const override;
   virtual inline void reset()
   {
     regexp_idx_ = common::OB_COMPACT_INVALID_INDEX;

src/sql/engine/expr/ob_expr_regexp_count.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprRegexpCount(common::ObIAllocator& alloc);
   virtual ~ObExprRegexpCount();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_regexp_instr.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprRegexpInstr(common::ObIAllocator& alloc);
   virtual ~ObExprRegexpInstr();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
   static int eval_regexp_instr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);

src/sql/engine/expr/ob_expr_regexp_like.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprRegexpLike(common::ObIAllocator& alloc);
   virtual ~ObExprRegexpLike();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_regexp_replace.h

@@ -24,9 +24,9 @@ public:
   explicit ObExprRegexpReplace(common::ObIAllocator& alloc);
   virtual ~ObExprRegexpReplace();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_regexp_substr.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprRegexpSubstr(common::ObIAllocator& alloc);
   virtual ~ObExprRegexpSubstr();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_repeat.h

@@ -22,7 +22,7 @@ public:
   explicit ObExprRepeat(common::ObIAllocator& alloc);
   virtual ~ObExprRepeat();
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& text, ObExprResType& count, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType& text, ObExprResType& count, common::ObExprTypeCtx& type_ctx) const override;
   ///@brief call function calc(), implementation of ObExprOperator::calc_result2()
   ///
   ///@param [out] result  result of RPEAT(str, count)
@@ -31,7 +31,7 @@ public:
   ///@param [in] allocator:ObExprStringBuf
   ///@return OB_SUCCESS success, others failure
   virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& text, const common::ObObj& count, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj& text, const common::ObObj& count, common::ObExprCtx& expr_ctx) const override;
   static int calc(common::ObObj& result, const common::ObObj& text, const common::ObObj& count,
       common::ObIAllocator* allocator, const common::ObObjType res_type, const int64_t max_result_size);
   static int calc(common::ObObj& result, const common::ObObjType type, const common::ObString& text,

src/sql/engine/expr/ob_expr_replace.h

@@ -24,7 +24,7 @@ public:
   explicit ObExprReplace(common::ObIAllocator& alloc);
   virtual ~ObExprReplace();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types_array, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types_array, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
 
   static int calc(common::ObObj& result, const common::ObObj& text, const common::ObObj& from, const common::ObObj& to,
       common::ObExprStringBuf& string_buf);

src/sql/engine/expr/ob_expr_sinh.h

@@ -20,8 +20,9 @@ class ObExprSinh : public ObFuncExprOperator {
 public:
   explicit ObExprSinh(common::ObIAllocator& alloc);
   virtual ~ObExprSinh();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type1(
+      ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
 private:

src/sql/engine/expr/ob_expr_sqrt.h

@@ -20,8 +20,8 @@ class ObExprSqrt : public ObFuncExprOperator {
 public:
   explicit ObExprSqrt(common::ObIAllocator& alloc);
   virtual ~ObExprSqrt();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
 private:

src/sql/engine/expr/ob_expr_str_to_date.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprStrToDate(common::ObIAllocator& alloc);
   virtual ~ObExprStrToDate();
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& date, ObExprResType& format, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& date, const common::ObObj& format, common::ObExprCtx& expr_ctx) const;
+      ObExprResType& type, ObExprResType& date, ObExprResType& format, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result2(common::ObObj& result, const common::ObObj& date, const common::ObObj& format,
+      common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
 private:

src/sql/engine/expr/ob_expr_strcmp.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprStrcmp(common::ObIAllocator& alloc);
   virtual ~ObExprStrcmp(){};
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result2(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override
   {

src/sql/engine/expr/ob_expr_subquery_greater_equal.h

@@ -30,7 +30,7 @@ public:
 
 private:
   virtual int compare_single_row(const common::ObNewRow& left_row, const common::ObNewRow& right_row,
-      common::ObExprCtx& expr_ctx, common::ObObj& result) const;
+      common::ObExprCtx& expr_ctx, common::ObObj& result) const override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObExprSubQueryGreaterEqual);

src/sql/engine/expr/ob_expr_subquery_greater_than.h

@@ -30,7 +30,7 @@ public:
 
 private:
   virtual int compare_single_row(const common::ObNewRow& left_row, const common::ObNewRow& right_row,
-      common::ObExprCtx& expr_ctx, common::ObObj& result) const;
+      common::ObExprCtx& expr_ctx, common::ObObj& result) const override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObExprSubQueryGreaterThan);

src/sql/engine/expr/ob_expr_subquery_less_equal.h

@@ -30,7 +30,7 @@ public:
 
 private:
   virtual int compare_single_row(const common::ObNewRow& left_row, const common::ObNewRow& right_row,
-      common::ObExprCtx& expr_ctx, common::ObObj& result) const;
+      common::ObExprCtx& expr_ctx, common::ObObj& result) const override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObExprSubQueryLessEqual);

src/sql/engine/expr/ob_expr_subquery_less_than.h

@@ -30,7 +30,7 @@ public:
 
 private:
   virtual int compare_single_row(const common::ObNewRow& left_row, const common::ObNewRow& right_row,
-      common::ObExprCtx& expr_ctx, common::ObObj& result) const;
+      common::ObExprCtx& expr_ctx, common::ObObj& result) const override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObExprSubQueryLessThan);

src/sql/engine/expr/ob_expr_subquery_not_equal.h

@@ -28,7 +28,7 @@ public:
 
 private:
   virtual int compare_single_row(const common::ObNewRow& left_row, const common::ObNewRow& right_row,
-      common::ObExprCtx& expr_ctx, common::ObObj& result) const;
+      common::ObExprCtx& expr_ctx, common::ObObj& result) const override;
 
 private:
   DISALLOW_COPY_AND_ASSIGN(ObExprSubQueryNotEqual);

src/sql/engine/expr/ob_expr_subquery_ns_equal.h

@@ -28,7 +28,7 @@ public:
 
 private:
   virtual int compare_single_row(const common::ObNewRow& left_row, const common::ObNewRow& right_row,
-      common::ObExprCtx& expr_ctx, common::ObObj& result) const;
+      common::ObExprCtx& expr_ctx, common::ObObj& result) const override;
   DISALLOW_COPY_AND_ASSIGN(ObExprSubQueryNSEqual);
 };
 }  // namespace sql

src/sql/engine/expr/ob_expr_subquery_ref.h

@@ -46,11 +46,11 @@ public:
   explicit ObExprSubQueryRef(common::ObIAllocator& alloc);
   virtual ~ObExprSubQueryRef();
 
-  virtual int assign(const ObExprOperator& other);
+  virtual int assign(const ObExprOperator& other) override;
 
-  virtual void reset();
-  virtual int calc_result_type0(ObExprResType& type, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const;
+  virtual void reset() override;
+  virtual int calc_result_type0(ObExprResType& type, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int expr_eval(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);

src/sql/engine/expr/ob_expr_substr.h

@@ -23,13 +23,13 @@ public:
   explicit ObExprSubstr(common::ObIAllocator& alloc);
   virtual ~ObExprSubstr();
   virtual int calc_result2(common::ObObj& result, const common::ObObj& text, const common::ObObj& start_pos,
-      common::ObExprCtx& expr_ctx) const;
+      common::ObExprCtx& expr_ctx) const override;
   virtual int calc_result3(common::ObObj& result, const common::ObObj& text, const common::ObObj& start_pos,
-      const common::ObObj& length, common::ObExprCtx& expr_ctx) const;
-  virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types_stack, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_array, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      const common::ObObj& length, common::ObExprCtx& expr_ctx) const override;
+  virtual int calc_result_typeN(ObExprResType& type, ObExprResType* types_stack, int64_t param_num,
+      common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_resultN(common::ObObj& result, const common::ObObj* objs_array, int64_t param_num,
+      common::ObExprCtx& expr_ctx) const override;
 
   static int substr(common::ObString& output, const common::ObString& input, const int64_t pos, const int64_t len,
       common::ObCollationType cs_type);

src/sql/engine/expr/ob_expr_substring_index.h

@@ -23,9 +23,9 @@ public:
   explicit ObExprSubstringIndex(common::ObIAllocator& alloc);
   virtual ~ObExprSubstringIndex();
   virtual int calc_result_type3(ObExprResType& type, ObExprResType& str, ObExprResType& delim, ObExprResType& count,
-      common::ObExprTypeCtx& type_ctx) const;
+      common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_result3(common::ObObj& result, const common::ObObj& str, const common::ObObj& delim,
-      const common::ObObj& count, common::ObExprCtx& expr_ctx) const;
+      const common::ObObj& count, common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_sys_connect_by_path.h

@@ -24,9 +24,9 @@ public:
   virtual ~ObExprSysConnectByPath()
   {}
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& left, const common::ObObj& right, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj& left, const common::ObObj& right, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_sys_path(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
   static int eval_sys_connect_by_path(

src/sql/engine/expr/ob_expr_sys_privilege_check.h

@@ -20,11 +20,11 @@ public:
   explicit ObExprSysPrivilegeCheck(common::ObIAllocator& alloc);
   virtual ~ObExprSysPrivilegeCheck();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
 
   /// obj_array(level, tenant, db, table)
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* obj_array, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* obj_array, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int eval_sys_privilege_check(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 

src/sql/engine/expr/ob_expr_timestamp_diff.h

@@ -22,10 +22,10 @@ public:
   explicit ObExprTimeStampDiff(common::ObIAllocator& alloc);
   virtual ~ObExprTimeStampDiff();
   virtual int calc_result_type3(ObExprResType& type, ObExprResType& unit, ObExprResType& left, ObExprResType& right,
-      common::ObExprTypeCtx& type_ctx) const;
+      common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_result3(common::ObObj& result, const common::ObObj& unit, const common::ObObj& left,
-      const common::ObObj& right, common::ObExprCtx& expr_ctx) const;
-  virtual common::ObCastMode get_cast_mode() const
+      const common::ObObj& right, common::ObExprCtx& expr_ctx) const override;
+  virtual common::ObCastMode get_cast_mode() const override
   {
     return CM_NULL_ON_WARN;
   }

src/sql/engine/expr/ob_expr_timestamp_nvl.h

@@ -22,9 +22,9 @@ public:
   explicit ObExprTimestampNvl(common::ObIAllocator& alloc);
   virtual ~ObExprTimestampNvl();
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_result2(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_timestampnvl(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 

src/sql/engine/expr/ob_expr_to_days.h

@@ -21,8 +21,9 @@ public:
   ObExprToDays();
   explicit ObExprToDays(common::ObIAllocator& alloc);
   virtual ~ObExprToDays();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& date, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& date, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type1(
+      ObExprResType& type, ObExprResType& date, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result1(common::ObObj& result, const common::ObObj& date, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
 private:

src/sql/engine/expr/ob_expr_to_interval.h

@@ -21,8 +21,8 @@ class ObExprToYMInterval : public ObFuncExprOperator {
 public:
   explicit ObExprToYMInterval(common::ObIAllocator& alloc);
   virtual ~ObExprToYMInterval();
-  int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
-  int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
+  int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const override;
+  int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_to_yminterval(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 
@@ -34,8 +34,8 @@ class ObExprToDSInterval : public ObFuncExprOperator {
 public:
   explicit ObExprToDSInterval(common::ObIAllocator& alloc);
   virtual ~ObExprToDSInterval();
-  int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
-  int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const;
+  int calc_result_type1(ObExprResType& type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const override;
+  int calc_result1(common::ObObj& result, const common::ObObj& obj, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_to_dsinterval(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
 
@@ -48,9 +48,9 @@ public:
   explicit ObExprNumToYMInterval(common::ObIAllocator& alloc);
   virtual ~ObExprNumToYMInterval();
   int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
-  int calc_result2(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
+  int calc_result2(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
   template <class T>
   static int calc_result_common(
       const T& obj1, const T& obj2, common::ObIAllocator& calc_buf, common::ObIntervalYMValue& ym_value);
@@ -66,9 +66,9 @@ public:
   explicit ObExprNumToDSInterval(common::ObIAllocator& alloc);
   virtual ~ObExprNumToDSInterval();
   int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
-  int calc_result2(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
+  int calc_result2(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
   template <class R, class T>
   static int calc_result_common(R& result, const T& obj1, const T& obj2, common::ObIAllocator& calc_buf);
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;

src/sql/engine/expr/ob_expr_to_number.h

@@ -38,7 +38,7 @@ public:
   virtual ~ObExprToNumber();
 
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_(const ObString& in_str, const ObString& in_fmt_str, ObIAllocator& alloc, number::ObNumber& res_nmb);
   // for engine 3.0
@@ -54,9 +54,9 @@ public:
   virtual ~ObExprToBinaryFloat();
 
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_(const ObString& in_str, const ObString& in_fmt_str, ObIAllocator& alloc, number::ObNumber& res_nmb);
   static int calc_to_binaryfloat_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
@@ -71,9 +71,9 @@ public:
   virtual ~ObExprToBinaryDouble();
 
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* objs, int64_t param_num, common::ObExprCtx& expr_ctx) const override;
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_to_binarydouble_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
 

src/sql/engine/expr/ob_expr_to_temporal_base.h

@@ -23,10 +23,10 @@ public:
   explicit ObExprToTemporalBase(common::ObIAllocator& alloc, ObExprOperatorType type, const char* name);
   virtual ~ObExprToTemporalBase()
   {}
-  virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types_array, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_array, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_typeN(ObExprResType& type, ObExprResType* types_array, int64_t param_num,
+      common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_resultN(common::ObObj& result, const common::ObObj* objs_array, int64_t param_num,
+      common::ObExprCtx& expr_ctx) const override;
   virtual int set_my_result_from_ob_time(
       common::ObExprCtx& expr_ctx, common::ObTime& ob_time, common::ObObj& result) const = 0;
   virtual common::ObObjType get_my_target_obj_type() const = 0;

src/sql/engine/expr/ob_expr_trim.h

@@ -41,7 +41,7 @@ public:
       const common::ObFixedArray<size_t, common::ObIAllocator>&);
 
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override
   {
     return deduce_result_type(type, types, param_num, type_ctx);
   }
@@ -49,8 +49,8 @@ public:
   static int deduce_result_type(
       ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx);
 
-  virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_array, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_resultN(common::ObObj& result, const common::ObObj* objs_array, int64_t param_num,
+      common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
@@ -84,10 +84,11 @@ public:
   explicit ObExprLtrim(common::ObIAllocator& alloc, ObExprOperatorType type, const char* name, int32_t param_num);
   virtual ~ObExprLtrim();
 
-  virtual int calc_result_type1(ObExprResType& res_type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;
+  virtual int calc_result_type1(
+      ObExprResType& res_type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const override;
 
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const
+      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const override
   {
     return deduce_result_type(type, types, param_num, type_ctx);
   }
@@ -95,12 +96,13 @@ public:
   static int deduce_result_type(
       ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx);
 
-  virtual int calc_result1(common::ObObj& res_obj, const common::ObObj& obj1, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result1(
+      common::ObObj& res_obj, const common::ObObj& obj1, common::ObExprCtx& expr_ctx) const override;
 
   int calc(common::ObObj& res_obj, const common::ObObj& obj1, common::ObExprCtx& expr_ctx, int64_t trim_type_val) const;
 
-  virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* objs_array, int64_t param_num, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_resultN(common::ObObj& result, const common::ObObj* objs_array, int64_t param_num,
+      common::ObExprCtx& expr_ctx) const override;
 
   static int calc_oracle_mode(common::ObObj& result, const int64_t trim_type, const common::ObString& pattern,
       const common::ObString& text, const common::ObObjType& res_type, common::ObExprCtx& expr_ctx,

src/sql/engine/expr/ob_expr_truncate.h

@@ -27,7 +27,7 @@ public:
 
   virtual int calc_result2(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
       common::ObExprCtx& expr_ctx) const override;
-  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const;
+  virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int set_trunc_val(
       common::ObObj& result, common::number::ObNumber& nmb, common::ObExprCtx& expr_ctx, common::ObObjType res_type);
 

src/sql/engine/expr/ob_expr_type_to_str.h

@@ -105,8 +105,8 @@ class ObExprSetToStr : public ObExprTypeToStr {
 public:
   explicit ObExprSetToStr(common::ObIAllocator& alloc);
   virtual ~ObExprSetToStr();
-  virtual int calc(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+  virtual int calc(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_to_str_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
 
@@ -119,8 +119,8 @@ class ObExprEnumToStr : public ObExprTypeToStr {
 public:
   explicit ObExprEnumToStr(common::ObIAllocator& alloc);
   virtual ~ObExprEnumToStr();
-  virtual int calc(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+  virtual int calc(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_to_str_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
 
@@ -134,9 +134,9 @@ public:
   explicit ObExprSetToInnerType(common::ObIAllocator& alloc);
   virtual ~ObExprSetToInnerType();
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_to_inner_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
 
@@ -150,9 +150,9 @@ public:
   explicit ObExprEnumToInnerType(common::ObIAllocator& alloc);
   virtual ~ObExprEnumToInnerType();
   virtual int calc_result_type2(
-      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc(
-      common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2, common::ObExprCtx& expr_ctx) const;
+      ObExprResType& type, ObExprResType& type1, ObExprResType& type2, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc(common::ObObj& result, const common::ObObj& obj1, const common::ObObj& obj2,
+      common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int calc_to_inner_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
 

src/sql/engine/expr/ob_expr_uid.h

@@ -21,8 +21,8 @@ class ObExprUid : public ObFuncExprOperator {
 public:
   explicit ObExprUid(common::ObIAllocator& alloc);
   virtual ~ObExprUid();
-  virtual int calc_result_type0(ObExprResType& type, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type0(ObExprResType& type, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const override;
   static int eval_uid(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_unhex.h

@@ -21,10 +21,11 @@ class ObExprUnhex : public ObStringExprOperator {
 public:
   explicit ObExprUnhex(common::ObIAllocator& alloc);
   virtual ~ObExprUnhex();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const;
-  static int calc(
-      common::ObObj& result, const common::ObObj& text, common::ObCastCtx& cast_ctx, common::ObExprCtx& expr_ctx);
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type1(
+      ObExprResType& type, ObExprResType& text, common::ObExprTypeCtx& type_ctx) const override;
+  static int calc(common::ObObj& result, const common::ObObj& text, common::ObCastCtx& cast_ctx, common::ObExprCtx& expr_ctx);
+  virtual int calc_result1(
+      common::ObObj& result, const common::ObObj& text, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
   static int eval_unhex(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
 

src/sql/engine/expr/ob_expr_unix_timestamp.h

@@ -22,9 +22,9 @@ public:
   explicit ObExprUnixTimestamp(common::ObIAllocator& alloc);
   virtual ~ObExprUnixTimestamp();
   virtual int calc_result_typeN(
-      ObExprResType& type, ObExprResType* type_array, int64_t param, common::ObExprTypeCtx& type_ctx) const;
+      ObExprResType& type, ObExprResType* type_array, int64_t param, common::ObExprTypeCtx& type_ctx) const override;
   virtual int calc_resultN(
-      common::ObObj& result, const common::ObObj* date_param, int64_t param, common::ObExprCtx& expr_ctx) const;
+      common::ObObj& result, const common::ObObj* date_param, int64_t param, common::ObExprCtx& expr_ctx) const override;
   static int calc(
       common::ObObj& result, const common::ObObj& dt_date, const ObExprResType& res_type, common::ObCastCtx& cast_ctx);
   static int eval_unix_timestamp(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res);

src/sql/engine/expr/ob_expr_usec_to_time.h

@@ -20,8 +20,10 @@ class ObExprUsecToTime : public ObFuncExprOperator {
 public:
   explicit ObExprUsecToTime(common::ObIAllocator& alloc);
   virtual ~ObExprUsecToTime();
-  virtual int calc_result_type1(ObExprResType& type, ObExprResType& usec, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result1(common::ObObj& result, const common::ObObj& usec, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result_type1(
+      ObExprResType& type, ObExprResType& usec, common::ObExprTypeCtx& type_ctx) const override;
+  virtual int calc_result1(
+      common::ObObj& result, const common::ObObj& usec, common::ObExprCtx& expr_ctx) const override;
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 
 private:

src/sql/engine/expr/ob_expr_user.h

@@ -22,7 +22,7 @@ public:
   explicit ObExprUser(common::ObIAllocator& alloc);
   virtual ~ObExprUser();
   virtual int calc_result_type0(ObExprResType& type, common::ObExprTypeCtx& type_ctx) const;
-  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const;
+  virtual int calc_result0(common::ObObj& result, common::ObExprCtx& expr_ctx) const override;
   static int eval_user(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);
   virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/expr/ob_expr_user_can_access_obj.h

@@ -25,10 +25,10 @@ public:
   explicit ObExprUserCanAccessObj(common::ObIAllocator& alloc);
   virtual ~ObExprUserCanAccessObj();
   virtual int calc_result_type3(ObExprResType& type, ObExprResType& arg1, ObExprResType& arg2, ObExprResType& arg3,
-      common::ObExprTypeCtx& type_ctx) const;
+      common::ObExprTypeCtx& type_ctx) const override;
 
   virtual int calc_result3(common::ObObj& result, const common::ObObj& arg1, const common::ObObj& arg2,
-      const common::ObObj& arg3, common::ObExprCtx& expr_ctx) const;
+      const common::ObObj& arg3, common::ObExprCtx& expr_ctx) const override;
 
   virtual int cg_expr(ObExprCGCtx& expr_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
 

src/sql/engine/join/ob_basic_nested_loop_join.h

@@ -73,8 +73,8 @@ protected:
 public:
   explicit ObBasicNestedLoopJoin(common::ObIAllocator& alloc);
   virtual ~ObBasicNestedLoopJoin();
-  virtual void reset();
-  virtual void reuse();
+  virtual void reset() override;
+  virtual void reuse() override;
   int init_param_count(int64_t count)
   {
     return init_array_size<>(rescan_params_, count);
@@ -95,7 +95,7 @@ public:
       other_join_conds_, N_INNER_GET, is_inner_get_, N_SELF_JOIN, is_self_join_);
 
 protected:
-  int get_next_left_row(ObJoinCtx& join_ctx) const;
+  int get_next_left_row(ObJoinCtx& join_ctx) const override;
   int prepare_rescan_params(ObBasicNestedLoopJoinCtx& join_ctx) const;
   inline bool use_batch_index_join(ObPhyOperatorType right_op_type) const
   {