diff --git a/mysys/mf_iocache.c b/mysys/mf_iocache.c
index 8ade76e922e..0b19aaf9015 100644
--- a/mysys/mf_iocache.c
+++ b/mysys/mf_iocache.c
@@ -1384,7 +1384,7 @@ static void copy_to_read_buffer(IO_CACHE *write_cache,
 
 static int _my_b_seq_read(IO_CACHE *info, uchar *Buffer, size_t Count)
 {
-  size_t length, diff_length, left_length= 0, save_count, max_length;
+  size_t length, diff_length, save_count, max_length;
   my_off_t pos_in_file;
   save_count=Count;
 
@@ -1435,7 +1435,6 @@ static int _my_b_seq_read(IO_CACHE *info, uchar *Buffer, size_t Count)
       */
       goto read_append_buffer;
     }
-    left_length+=length;
     diff_length=0;
   }
 
diff --git a/sql/item_func.cc b/sql/item_func.cc
index 7b39b7710fb..6b8025c9d0f 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -2756,7 +2756,6 @@ bool Item_func_min_max::fix_length_and_dec()
   max_length=0;
   maybe_null=0;
   Item_result tmp_cmp_type= args[0]->cmp_type();
-  uint string_type_count= 0;
   uint temporal_type_count= 0;
   enum_field_types temporal_field_type= MYSQL_TYPE_DATETIME;
 
@@ -2769,7 +2768,6 @@ bool Item_func_min_max::fix_length_and_dec()
     if (args[i]->maybe_null)
       maybe_null= 1;
     tmp_cmp_type= item_cmp_type(tmp_cmp_type, args[i]->cmp_type());
-    string_type_count+= args[i]->cmp_type() == STRING_RESULT;
     if (args[i]->cmp_type() == TIME_RESULT)
     {
       if (!temporal_type_count)
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index ce706209017..fcdb671941d 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -3928,7 +3928,7 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
   int error= 0;
   TABLE *UNINIT_VAR(table); /* inited in all loops */
   uint i,table_count,const_count,key;
-  table_map found_const_table_map, all_table_map, found_ref, refs;
+  table_map found_const_table_map, all_table_map;
   key_map const_ref, eq_part;
   bool has_expensive_keyparts;
   TABLE **table_vector;
@@ -4191,7 +4191,6 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
   {
     ref_changed = 0;
   more_const_tables_found:
-    found_ref=0;
 
     /*
       We only have to loop from stat_vector + const_count as
@@ -4280,7 +4279,6 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
 	  key=keyuse->key;
 	  s->keys.set_bit(key);               // TODO: remove this ?
 
-	  refs=0;
           const_ref.clear_all();
 	  eq_part.clear_all();
           has_expensive_keyparts= false;
@@ -4296,8 +4294,6 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
                 if (keyuse->val->is_expensive())
                   has_expensive_keyparts= true;
               }
-	      else
-		refs|=keyuse->used_tables;
 	      eq_part.set_bit(keyuse->keypart);
 	    }
 	    keyuse++;
@@ -4348,8 +4344,6 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
 		  found_const_table_map|= table->map;
 	        break;
 	      }
-	      else
-	        found_ref|= refs;      // Table is const if all refs are const
 	    }
             else if (base_const_ref == base_eq_part)
               s->const_keys.set_bit(key);
@@ -26190,7 +26184,6 @@ static bool get_range_limit_read_cost(const JOIN_TAB *tab,
     */
     if (tab)
     {
-      key_part_map const_parts= 0;
       key_part_map map= 1;
       uint kp;
       /* Find how many key parts would be used by ref(const) */
@@ -26198,7 +26191,6 @@ static bool get_range_limit_read_cost(const JOIN_TAB *tab,
       {
         if (!(table->const_key_parts[keynr] & map))
           break;
-        const_parts |= map;
       }
       
       if (kp > 0)
diff --git a/storage/innobase/fil/fil0crypt.cc b/storage/innobase/fil/fil0crypt.cc
index 8195716f722..94899ed0f65 100644
--- a/storage/innobase/fil/fil0crypt.cc
+++ b/storage/innobase/fil/fil0crypt.cc
@@ -1012,13 +1012,11 @@ static bool fil_crypt_start_encrypting_space(fil_space_t* space)
 		/* 4 - sync tablespace before publishing crypt data */
 
 		bool success = false;
-		ulint sum_pages = 0;
 
 		do {
 			ulint n_pages = 0;
 			success = buf_flush_lists(ULINT_MAX, end_lsn, &n_pages);
 			buf_flush_wait_batch_end(NULL, BUF_FLUSH_LIST);
-			sum_pages += n_pages;
 		} while (!success);
 
 		/* 5 - publish crypt data */
diff --git a/storage/innobase/fsp/fsp0fsp.cc b/storage/innobase/fsp/fsp0fsp.cc
index 58aa18ac323..cb5eff07f88 100644
--- a/storage/innobase/fsp/fsp0fsp.cc
+++ b/storage/innobase/fsp/fsp0fsp.cc
@@ -2719,7 +2719,6 @@ fsp_reserve_free_extents(
 	ulint		n_free;
 	ulint		n_free_up;
 	ulint		reserve;
-	size_t		total_reserved = 0;
 
 	ut_ad(mtr);
 	*n_reserved = n_ext;
@@ -2801,7 +2800,6 @@ try_again:
 	}
 try_to_extend:
 	if (ulint n = fsp_try_extend_data_file(space, space_header, mtr)) {
-		total_reserved += n;
 		goto try_again;
 	}
 
diff --git a/storage/innobase/row/row0ftsort.cc b/storage/innobase/row/row0ftsort.cc
index 2ca930e0934..29e126290cf 100644
--- a/storage/innobase/row/row0ftsort.cc
+++ b/storage/innobase/row/row0ftsort.cc
@@ -770,7 +770,6 @@ fts_parallel_tokenization(
 	row_merge_block_t**	crypt_block;
 	int			tmpfd[FTS_NUM_AUX_INDEX];
 	ulint			mycount[FTS_NUM_AUX_INDEX];
-	ib_uint64_t		total_rec = 0;
 	ulint			num_doc_processed = 0;
 	doc_id_t		last_doc_id = 0;
 	mem_heap_t*		blob_heap = NULL;
@@ -1038,7 +1037,6 @@ exit:
 			goto func_exit;
 		}
 
-		total_rec += merge_file[i]->n_rec;
 		close(tmpfd[i]);
 	}
 
diff --git a/storage/maria/ma_check.c b/storage/maria/ma_check.c
index 2795528a044..cb4585d0f62 100644
--- a/storage/maria/ma_check.c
+++ b/storage/maria/ma_check.c
@@ -4191,7 +4191,7 @@ int maria_repair_parallel(HA_CHECK *param, register MARIA_HA *info,
 			const char * name, my_bool rep_quick)
 {
   int got_error;
-  uint i,key, total_key_length, istep;
+  uint i,key, istep;
   ha_rows start_records;
   my_off_t new_header_length,del;
   File new_file;
@@ -4353,7 +4353,9 @@ int maria_repair_parallel(HA_CHECK *param, register MARIA_HA *info,
     _ma_check_print_error(param,"Not enough memory for key!");
     goto err;
   }
-  total_key_length=0;
+#ifdef USING_SECOND_APPROACH
+  uint total_key_length=0;
+#endif
   rec_per_key_part= param->new_rec_per_key_part;
   share->state.state.records=share->state.state.del=share->state.split=0;
   share->state.state.empty=0;
@@ -4422,7 +4424,9 @@ int maria_repair_parallel(HA_CHECK *param, register MARIA_HA *info,
       if (keyseg->flag & HA_NULL_PART)
         sort_param[i].key_length++;
     }
+#ifdef USING_SECOND_APPROACH
     total_key_length+=sort_param[i].key_length;
+#endif
 
     if (sort_param[i].keyinfo->flag & HA_FULLTEXT)
     {
diff --git a/storage/myisam/mi_check.c b/storage/myisam/mi_check.c
index d9b9bb5af4a..8bae409d1e6 100644
--- a/storage/myisam/mi_check.c
+++ b/storage/myisam/mi_check.c
@@ -2614,7 +2614,7 @@ int mi_repair_parallel(HA_CHECK *param, register MI_INFO *info,
 			const char * name, int rep_quick)
 {
   int got_error;
-  uint i,key, total_key_length, istep;
+  uint i,key, istep;
   ulong rec_length;
   ha_rows start_records;
   my_off_t new_header_length,del;
@@ -2800,7 +2800,9 @@ int mi_repair_parallel(HA_CHECK *param, register MI_INFO *info,
     mi_check_print_error(param,"Not enough memory for key!");
     goto err;
   }
-  total_key_length=0;
+#ifdef USING_SECOND_APPROACH
+  uint total_key_length=0;
+#endif
   rec_per_key_part= param->rec_per_key_part;
   info->state->records=info->state->del=share->state.split=0;
   info->state->empty=0;
@@ -2869,7 +2871,9 @@ int mi_repair_parallel(HA_CHECK *param, register MI_INFO *info,
       if (keyseg->flag & HA_NULL_PART)
         sort_param[i].key_length++;
     }
+#ifdef USING_SECOND_APPROACH
     total_key_length+=sort_param[i].key_length;
+#endif
 
     if (sort_param[i].keyinfo->flag & HA_FULLTEXT)
     {