EXPLAIN FORMAT=JSON: Add support for single-table UPDATE/DELETE.

mysql-test/r/explain_json.result

@@ -199,7 +199,7 @@ EXPLAIN
         },
         {
           "query_block": {
-            "select_id": 1,
+            "select_id": 2,
             "table": {
               "table_name": "B",
               "access_type": "ALL",
@@ -233,7 +233,7 @@ EXPLAIN
         },
         {
           "query_block": {
-            "select_id": 1,
+            "select_id": 2,
             "table": {
               "table_name": "B",
               "access_type": "ALL",
@@ -265,7 +265,7 @@ EXPLAIN
     "subqueries": [
       {
         "query_block": {
-          "select_id": 1,
+          "select_id": 2,
           "table": {
             "table_name": "t1",
             "access_type": "ALL",
@@ -295,7 +295,7 @@ EXPLAIN
     "subqueries": [
       {
         "query_block": {
-          "select_id": 1,
+          "select_id": 2,
           "table": {
             "table_name": "t1",
             "access_type": "ALL",
@@ -342,4 +342,55 @@ EXPLAIN
   }
 }
 drop table t1;
+#
+# Single-table UPDATE/DELETE
+#
+explain format=json delete from t0;
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "message": "Deleting all rows"
+    }
+  }
+}
+explain format=json delete from t0 where 1 > 2;
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "message": "Impossible WHERE"
+    }
+  }
+}
+explain format=json delete from t0 where a < 3;
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "delete": 1,
+      "table_name": "t0",
+      "access_type": "ALL",
+      "rows": 10,
+      "attached_condition": "(t0.a < 3)"
+    }
+  }
+}
+explain format=json update t0 set a=3 where a in (2,3,4);
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "update": 1,
+      "table_name": "t0",
+      "access_type": "ALL",
+      "rows": 10,
+      "attached_condition": "(t0.a in (2,3,4))"
+    }
+  }
+}
 drop table t0;

mysql-test/t/explain_json.test

@@ -70,5 +70,15 @@ select * from t1 A, t1 B where A.a=B.a and A.b < 3 and B.b < 5;
 
 drop table t1;
 
+--echo #
+--echo # Single-table UPDATE/DELETE
+--echo #
+explain format=json delete from t0;
+explain format=json delete from t0 where 1 > 2;
+
+explain format=json delete from t0 where a < 3;
+
+explain format=json update t0 set a=3 where a in (2,3,4);
+
 drop table t0;
 

sql/sql_delete.cc

@@ -51,7 +51,7 @@
     invoked on a running DELETE statement.
 */
 
-void Delete_plan::save_explain_data(Explain_query *query)
+void Delete_plan::save_explain_data(MEM_ROOT *mem_root, Explain_query *query)
 {
   Explain_delete* explain= new Explain_delete;
 
@@ -64,22 +64,23 @@ void Delete_plan::save_explain_data(Explain_query *query)
   else
   {
     explain->deleting_all_rows= false;
-    Update_plan::save_explain_data_intern(query, explain);
+    Update_plan::save_explain_data_intern(mem_root, query, explain);
   }
  
   query->add_upd_del_plan(explain);
 }
 
 
-void Update_plan::save_explain_data(Explain_query *query)
+void Update_plan::save_explain_data(MEM_ROOT *mem_root, Explain_query *query)
 {
   Explain_update* explain= new Explain_update;
-  save_explain_data_intern(query, explain);
+  save_explain_data_intern(mem_root, query, explain);
   query->add_upd_del_plan(explain);
 }
 
 
-void Update_plan::save_explain_data_intern(Explain_query *query, 
+void Update_plan::save_explain_data_intern(MEM_ROOT *mem_root,
+                                           Explain_query *query, 
                                            Explain_update *explain)
 {
   explain->select_type= "SIMPLE";
@@ -141,10 +142,12 @@ void Update_plan::save_explain_data_intern(Explain_query *query,
   }
 
   explain->using_where= MY_TEST(select && select->cond);
+  explain->where_cond= select? select->cond: NULL;
   explain->using_filesort= using_filesort;
   explain->using_io_buffer= using_io_buffer;
 
-  make_possible_keys_line(table, possible_keys, &explain->possible_keys_line);
+  append_possible_keys(mem_root, explain->possible_keys, table, 
+                       possible_keys);
 
   explain->quick_info= NULL;
 
@@ -157,11 +160,8 @@ void Update_plan::save_explain_data_intern(Explain_query *query,
   {
     if (index != MAX_KEY)
     {
-      explain->key_str.append(table->key_info[index].name);
-      char buf[64];
-      size_t length;
-      length= longlong10_to_str(table->key_info[index].key_length, buf, 10) - buf;
-      explain->key_len_str.append(buf, length);
+      explain->key.set(mem_root, &table->key_info[index],
+                       table->key_info[index].key_length);
     }
   }
   explain->rows= scanned_rows;
@@ -460,7 +460,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   if (thd->lex->describe)
     goto produce_explain_and_leave;
   
-  query_plan.save_explain_data(thd->lex->explain);
+  query_plan.save_explain_data(thd->mem_root, thd->lex->explain);
 
   DBUG_EXECUTE_IF("show_explain_probe_delete_exec_start", 
                   dbug_serve_apcs(thd, 1););
@@ -698,7 +698,7 @@ produce_explain_and_leave:
     We come here for various "degenerate" query plans: impossible WHERE,
     no-partitions-used, impossible-range, etc.
   */
-  query_plan.save_explain_data(thd->lex->explain);
+  query_plan.save_explain_data(thd->mem_root, thd->lex->explain);
 
 send_nothing_and_leave:
   /* 

sql/sql_explain.h

@@ -432,6 +432,11 @@ class Explain_index_use : public Sql_alloc
 public:
   String_list key_parts_list;
   
+  Explain_index_use()
+  {
+    clear();
+  }
+
   void clear()
   {
     key_name= NULL;
@@ -440,8 +445,8 @@ public:
   void set(MEM_ROOT *root, KEY *key_name, uint key_len_arg);
   void set_pseudo_key(MEM_ROOT *root, const char *key_name);
 
-  inline const char *get_key_name() { return key_name; }
-  inline uint get_key_len() { return key_len; }
+  inline const char *get_key_name() const { return key_name; }
+  inline uint get_key_len() const { return key_len; }
 };
 
 
@@ -584,8 +589,8 @@ public:
 
 private:
   void append_tag_name(String *str, enum explain_extra_tag tag);
-  void fill_key_str(String *key_str, bool is_json);
-  void fill_key_len_str(String *key_len_str);
+  void fill_key_str(String *key_str, bool is_json) const;
+  void fill_key_len_str(String *key_len_str) const;
   double get_r_filtered();
   void tag_to_json(Json_writer *writer, enum explain_extra_tag tag);
 };
@@ -614,14 +619,22 @@ public:
   StringBuffer<64> table_name;
 
   enum join_type jtype;
-  StringBuffer<128> possible_keys_line;
-  StringBuffer<128> key_str;
-  StringBuffer<128> key_len_str;
+  String_list possible_keys;
+
+  /* Used key when doing a full index scan (possibly with limit) */
+  Explain_index_use key;
+
+  /* 
+    MRR that's used with quick select. This should probably belong to the
+    quick select
+  */
   StringBuffer<64> mrr_type;
   
   Explain_quick_select *quick_info;
 
   bool using_where;
+  Item *where_cond;
+
   ha_rows rows;
 
   bool using_filesort;
@@ -632,8 +645,8 @@ public:
 
   virtual int print_explain(Explain_query *query, select_result_sink *output, 
                             uint8 explain_flags, bool is_analyze);
-  virtual void print_explain_json(Explain_query *query, Json_writer *writer, bool is_analyze)
-  { /* EXPLAIN_JSON_NOT_IMPL */}
+  virtual void print_explain_json(Explain_query *query, Json_writer *writer,
+                                  bool is_analyze);
 };
 
 
@@ -678,8 +691,8 @@ public:
 
   virtual int print_explain(Explain_query *query, select_result_sink *output, 
                             uint8 explain_flags, bool is_analyze);
-  virtual void print_explain_json(Explain_query *query, Json_writer *writer, bool is_analyze)
-  { /* EXPLAIN_JSON_NOT_IMPL */}
+  virtual void print_explain_json(Explain_query *query, Json_writer *writer,
+                                  bool is_analyze);
 };
 
 

sql/sql_lex.h

@@ -2303,8 +2303,9 @@ public:
   void set_impossible_where() { impossible_where= true; }
   void set_no_partitions() { no_partitions= true; }
 
-  void save_explain_data(Explain_query *query);
-  void save_explain_data_intern(Explain_query *query, Explain_update *eu);
+  void save_explain_data(MEM_ROOT *mem_root, Explain_query *query);
+  void save_explain_data_intern(MEM_ROOT *mem_root, Explain_query *query,
+                                Explain_update *eu);
 
   virtual ~Update_plan() {}
 
@@ -2335,7 +2336,7 @@ public:
     scanned_rows= rows_arg;
   }
 
-  void save_explain_data(Explain_query *query);
+  void save_explain_data(MEM_ROOT *mem_root, Explain_query *query);
 };
 
 

sql/sql_select.cc

@@ -23126,135 +23126,7 @@ int print_explain_message_line(select_result_sink *result,
   return 0;
 }
 
-
-/*
-  Make a comma-separated list of possible_keys names and add it into the string
-*/ 
-
-void make_possible_keys_line(TABLE *table, key_map possible_keys, String *line)
-{
-  if (!possible_keys.is_clear_all())
-  {
-    uint j;
-    for (j=0 ; j < table->s->keys ; j++)
-    {
-      if (possible_keys.is_set(j))
-      {
-        if (line->length())
-          line->append(',');
-        line->append(table->key_info[j].name, 
-                     strlen(table->key_info[j].name),
-                     system_charset_info);
-      }
-    }
-  }
-}
-
-/*
-  Print an EXPLAIN output row, based on information provided in the parameters
-
-  @note
-    Parameters that may have NULL value in EXPLAIN output, should be passed
-    (char*)NULL.
-
-  @return 
-    0  - OK
-    1  - OOM Error
-*/
-
-int print_explain_row(select_result_sink *result,
-                      uint8 options, bool is_analyze,
-                      uint select_number,
-                      const char *select_type,
-                      const char *table_name,
-                      const char *partitions,
-                      enum join_type jtype,
-                      const char *possible_keys,
-                      const char *index,
-                      const char *key_len,
-                      const char *ref,
-                      ha_rows *rows,
-                      ha_rows *r_rows,
-                      double r_filtered,
-                      const char *extra)
-{
-  Item *item_null= new Item_null();
-  List<Item> item_list;
-  Item *item;
-
-  item_list.push_back(new Item_int((int32) select_number));
-  item_list.push_back(new Item_string_sys(select_type));
-  item_list.push_back(new Item_string_sys(table_name));
-  if (options & DESCRIBE_PARTITIONS)
-  {
-    if (partitions)
-    {
-      item_list.push_back(new Item_string_sys(partitions));
-    }
-    else
-      item_list.push_back(item_null);
-  }
-  
-  const char *jtype_str= join_type_str[jtype];
-  item_list.push_back(new Item_string_sys(jtype_str));
-  
-  item= possible_keys? new Item_string_sys(possible_keys) : item_null;
-  item_list.push_back(item);
-  
-  /* 'index */
-  item= index ? new Item_string_sys(index) : item_null;
-  item_list.push_back(item);
-  
-  /* 'key_len */
-  item= key_len ? new Item_string_sys(key_len) : item_null;
-  item_list.push_back(item);
-  
-  /* 'ref' */
-  item= ref ? new Item_string_sys(ref) : item_null;
-  item_list.push_back(item);
-
-  /* 'rows' */
-  if (rows)
-  {
-    item_list.push_back(new Item_int(*rows, 
-                                     MY_INT64_NUM_DECIMAL_DIGITS));
-  }
-  else
-    item_list.push_back(item_null);
-  
-  /* 'r_rows' */
-  if (is_analyze)
-  {
-    if (r_rows)
-    {
-      item_list.push_back(new Item_int(*r_rows, 
-                                       MY_INT64_NUM_DECIMAL_DIGITS));
-    }
-    else
-      item_list.push_back(item_null);
-  }
-
-  /* 'filtered' */
-  const double filtered=100.0;
-  if (options & DESCRIBE_EXTENDED || is_analyze)
-    item_list.push_back(new Item_float(filtered, 2));
-  
-  /* 'r_filtered' */
-  if (is_analyze)
-    item_list.push_back(new Item_float(r_filtered, 2));
-  
-  /* 'Extra' */
-  if (extra)
-    item_list.push_back(new Item_string_sys(extra));
-  else
-    item_list.push_back(item_null);
-
-  if (result->send_data(item_list))
-    return 1;
-  return 0;
-}
-
-
+#if 0
 int print_fake_select_lex_join(select_result_sink *result, bool on_the_fly,
                                SELECT_LEX *select_lex, uint8 explain_flags)
 {
@@ -23327,7 +23199,7 @@ int print_fake_select_lex_join(select_result_sink *result, bool on_the_fly,
     return 1;
   return 0;
 }
-
+#endif
 
 /*
   Append MRR information from quick select to the given string

sql/sql_select.h

@@ -1832,8 +1832,10 @@ inline bool optimizer_flag(THD *thd, uint flag)
   return (thd->variables.optimizer_switch & flag);
 }
 
+/*
 int print_fake_select_lex_join(select_result_sink *result, bool on_the_fly,
                                SELECT_LEX *select_lex, uint8 select_options);
+*/
 
 uint get_index_for_order(ORDER *order, TABLE *table, SQL_SELECT *select,
                          ha_rows limit, ha_rows *scanned_limit, 
@@ -1861,22 +1863,8 @@ int print_explain_message_line(select_result_sink *result,
                                ha_rows *rows,
                                const char *message);
 void explain_append_mrr_info(QUICK_RANGE_SELECT *quick, String *res);
-int print_explain_row(select_result_sink *result,
-                      uint8 options, bool is_analyze,
-                      uint select_number,
-                      const char *select_type,
-                      const char *table_name,
-                      const char *partitions,
-                      enum join_type jtype,
-                      const char *possible_keys,
-                      const char *index,
-                      const char *key_len,
-                      const char *ref,
-                      ha_rows *rows,
-                      ha_rows *r_rows,
-                      double r_filtered,
-                      const char *extra);
-void make_possible_keys_line(TABLE *table, key_map possible_keys, String *line);
+int append_possible_keys(MEM_ROOT *alloc, String_list &list, TABLE *table, 
+                         key_map possible_keys);
 
 /****************************************************************************
   Temporary table support for SQL Runtime

sql/sql_update.cc

@@ -517,7 +517,7 @@ int mysql_update(THD *thd,
   */
   if (thd->lex->describe)
     goto produce_explain_and_leave;
-  query_plan.save_explain_data(thd->lex->explain);
+  query_plan.save_explain_data(thd->mem_root, thd->lex->explain);
 
   DBUG_EXECUTE_IF("show_explain_probe_update_exec_start", 
                   dbug_serve_apcs(thd, 1););
@@ -1037,7 +1037,7 @@ produce_explain_and_leave:
     We come here for various "degenerate" query plans: impossible WHERE,
     no-partitions-used, impossible-range, etc.
   */
-  query_plan.save_explain_data(thd->lex->explain);
+  query_plan.save_explain_data(thd->mem_root, thd->lex->explain);
 
 emit_explain_and_leave:
   int err2= thd->lex->explain->send_explain(thd);