my_alloc.c

- Changed 0x%lx -> %p
array.c:
- Static (preallocated) buffer can now be anywhere
my_sys.h
- Define MY_INIT_BUFFER_USED
sql_delete.cc & sql_lex.cc
- Use memroot when allocating classes (avoids call to current_thd)
sql_explain.h:
- Use preallocated buffers
sql_explain.cc:
- Use preallocated buffers and memroot
sql_select.cc:
- Use multi_alloc_root() instead of many alloc_root()
- Update calls to Explain

mysql-test/suite/sys_vars/r/sysvars_server_notembedded.result

@@ -3116,10 +3116,10 @@ ENUM_VALUE_LIST	NULL
 READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	NULL
 VARIABLE_NAME	QUERY_ALLOC_BLOCK_SIZE
-SESSION_VALUE	8192
-GLOBAL_VALUE	8192
+SESSION_VALUE	16384
+GLOBAL_VALUE	16384
 GLOBAL_VALUE_ORIGIN	COMPILE-TIME
-DEFAULT_VALUE	8192
+DEFAULT_VALUE	16384
 VARIABLE_SCOPE	SESSION
 VARIABLE_TYPE	BIGINT UNSIGNED
 VARIABLE_COMMENT	Allocation block size for query parsing and execution
@@ -3214,14 +3214,14 @@ ENUM_VALUE_LIST	OFF,ON
 READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	OPTIONAL
 VARIABLE_NAME	QUERY_PREALLOC_SIZE
-SESSION_VALUE	8192
-GLOBAL_VALUE	8192
+SESSION_VALUE	24576
+GLOBAL_VALUE	24576
 GLOBAL_VALUE_ORIGIN	COMPILE-TIME
-DEFAULT_VALUE	8192
+DEFAULT_VALUE	24576
 VARIABLE_SCOPE	SESSION
 VARIABLE_TYPE	BIGINT UNSIGNED
 VARIABLE_COMMENT	Persistent buffer for query parsing and execution
-NUMERIC_MIN_VALUE	8192
+NUMERIC_MIN_VALUE	1024
 NUMERIC_MAX_VALUE	4294967295
 NUMERIC_BLOCK_SIZE	1024
 ENUM_VALUE_LIST	NULL

sql/sql_delete.cc

@@ -54,7 +54,7 @@
 
 void Delete_plan::save_explain_data(MEM_ROOT *mem_root, Explain_query *query)
 {
-  Explain_delete* explain= new Explain_delete;
+  Explain_delete *explain= new (mem_root) Explain_delete(mem_root);
 
   if (deleting_all_rows)
   {
@@ -74,7 +74,7 @@ void Delete_plan::save_explain_data(MEM_ROOT *mem_root, Explain_query *query)
 
 void Update_plan::save_explain_data(MEM_ROOT *mem_root, Explain_query *query)
 {
-  Explain_update* explain= new Explain_update;
+  Explain_update* explain= new (mem_root) Explain_update(mem_root);
   save_explain_data_intern(mem_root, query, explain);
   query->add_upd_del_plan(explain);
 }

sql/sql_explain.cc

@@ -27,10 +27,11 @@ const char * STR_DELETING_ALL_ROWS= "Deleting all rows";
 const char * STR_IMPOSSIBLE_WHERE= "Impossible WHERE";
 const char * STR_NO_ROWS_AFTER_PRUNING= "No matching rows after partition pruning";
 
-Explain_query::Explain_query(THD *thd_arg) : 
-  upd_del_plan(NULL), insert_plan(NULL), thd(thd_arg), apc_enabled(false)
+Explain_query::Explain_query(THD *thd_arg, MEM_ROOT *root) : 
+  mem_root(root), upd_del_plan(NULL),  insert_plan(NULL),
+  unions(root), selects(root),  thd(thd_arg), apc_enabled(false),
+  operations(0)
 {
-  operations= 0;
 }
 
 
@@ -140,7 +141,7 @@ int Explain_query::send_explain(THD *thd)
   select_result *result;
   LEX *lex= thd->lex;
  
-  if (!(result= new select_send()) || 
+  if (!(result= new (thd->mem_root) select_send()) || 
       thd->send_explain_fields(result, lex->describe, lex->analyze_stmt))
     return 1;
 
@@ -225,7 +226,8 @@ bool print_explain_for_slow_log(LEX *lex, THD *thd, String *str)
   Return tabular EXPLAIN output as a text string
 */
 
-bool Explain_query::print_explain_str(THD *thd, String *out_str,  bool is_analyze)
+bool Explain_query::print_explain_str(THD *thd, String *out_str,
+                                      bool is_analyze)
 {
   List<Item> fields;
   thd->make_explain_field_list(fields, thd->lex->describe, is_analyze);
@@ -551,6 +553,20 @@ int Explain_node::print_explain_for_children(Explain_query *query,
   return 0;
 }
 
+bool Explain_basic_join::add_table(Explain_table_access *tab, Explain_query *query)
+{
+  if (!join_tabs)
+  {
+    n_join_tabs= 0;
+    if (!(join_tabs= ((Explain_table_access**)
+                      alloc_root(query->mem_root,
+                                 sizeof(Explain_table_access*) *
+                                 MAX_TABLES))))
+      return true;
+  }
+  join_tabs[n_join_tabs++]= tab;
+  return false;
+}
 
 /*
   This tells whether a child subquery should be printed in JSON output.
@@ -609,7 +625,6 @@ Explain_basic_join::~Explain_basic_join()
   {
     for (uint i= 0; i< n_join_tabs; i++)
       delete join_tabs[i];
-    my_free(join_tabs);
   }
 } 
 
@@ -1895,9 +1910,12 @@ void delete_explain_query(LEX *lex)
 void create_explain_query(LEX *lex, MEM_ROOT *mem_root)
 {
   DBUG_ASSERT(!lex->explain);
-  lex->explain= new Explain_query(lex->thd);
+  DBUG_ENTER("create_explain_query");
+
+  lex->explain= new (mem_root) Explain_query(lex->thd, mem_root);
   DBUG_ASSERT(mem_root == current_thd->mem_root);
-  lex->explain->mem_root= mem_root;
+
+  DBUG_VOID_RETURN;
 }
 
 void create_explain_query_if_not_exists(LEX *lex, MEM_ROOT *mem_root)

sql/sql_explain.h

@@ -90,6 +90,9 @@ class Json_writer;
 class Explain_node : public Sql_alloc
 {
 public:
+  Explain_node(MEM_ROOT *root)
+    :children(root)
+  {}
   /* A type specifying what kind of node this is */
   enum explain_node_type 
   {
@@ -158,20 +161,10 @@ class Explain_basic_join : public Explain_node
 public:
   enum explain_node_type get_type() { return EXPLAIN_BASIC_JOIN; }
   
-  Explain_basic_join() : join_tabs(NULL) {}
+  Explain_basic_join(MEM_ROOT *root) : Explain_node(root), join_tabs(NULL) {}
   ~Explain_basic_join();
 
-  bool add_table(Explain_table_access *tab)
-  {
-    if (!join_tabs)
-    {
-      join_tabs= (Explain_table_access**) my_malloc(sizeof(Explain_table_access*) *
-                                                MAX_TABLES, MYF(0));
-      n_join_tabs= 0;
-    }
-    join_tabs[n_join_tabs++]= tab;
-    return false;
-  }
+  bool add_table(Explain_table_access *tab, Explain_query *query);
 
   int get_select_id() { return select_id; }
 
@@ -199,8 +192,8 @@ class Explain_basic_join : public Explain_node
 
   In the non-degenerate case, a SELECT may have a GROUP BY/ORDER BY operation.
 
-  In both cases, the select may have children nodes. class Explain_node provides
-  a way get node's children.
+  In both cases, the select may have children nodes. class Explain_node
+  provides a way get node's children.
 */
 
 class Explain_select : public Explain_basic_join
@@ -208,7 +201,8 @@ class Explain_select : public Explain_basic_join
 public:
   enum explain_node_type get_type() { return EXPLAIN_SELECT; }
 
-  Explain_select() : 
+  Explain_select(MEM_ROOT *root) : 
+  Explain_basic_join(root),
     message(NULL),
     using_temporary(false), using_filesort(false)
   {}
@@ -255,6 +249,10 @@ class Explain_select : public Explain_basic_join
 class Explain_union : public Explain_node
 {
 public:
+  Explain_union(MEM_ROOT *root) : 
+  Explain_node(root)
+  {}
+
   enum explain_node_type get_type() { return EXPLAIN_UNION; }
 
   int get_select_id()
@@ -348,7 +346,7 @@ class Explain_insert;
 class Explain_query : public Sql_alloc
 {
 public:
-  Explain_query(THD *thd);
+  Explain_query(THD *thd, MEM_ROOT *root);
   ~Explain_query();
 
   /* Add a new node */
@@ -536,9 +534,10 @@ class Explain_quick_select : public Sql_alloc
 class Explain_table_access : public Sql_alloc
 {
 public:
-  Explain_table_access() :
+  Explain_table_access(MEM_ROOT *root) :
     derived_select_number(0),
     non_merged_sjm_number(0),
+    extra_tags(root),
     start_dups_weedout(false),
     end_dups_weedout(false),
     where_cond(NULL),
@@ -551,9 +550,13 @@ class Explain_table_access : public Sql_alloc
   void push_extra(enum explain_extra_tag extra_tag);
 
   /* Internals */
-public:
+
   /* id and 'select_type' are cared-of by the parent Explain_select */
   StringBuffer<32> table_name;
+  StringBuffer<32> used_partitions;
+  // valid with ET_USING_MRR
+  StringBuffer<32> mrr_type;
+  StringBuffer<32> firstmatch_table_name;
 
   /* 
     Non-zero number means this is a derived table. The number can be used to
@@ -565,11 +568,15 @@ class Explain_table_access : public Sql_alloc
 
   enum join_type type;
 
-  StringBuffer<32> used_partitions;
   bool used_partitions_set;
   
   /* Empty means "NULL" will be printed */
   String_list possible_keys;
+
+  bool rows_set; /* not set means 'NULL' should be printed */
+  bool filtered_set; /* not set means 'NULL' should be printed */
+  // Valid if ET_USING_INDEX_FOR_GROUP_BY is present
+  bool loose_scan_is_scanning;
   
   /*
     Index use: key name and length.
@@ -589,10 +596,7 @@ class Explain_table_access : public Sql_alloc
   
   String_list ref_list;
 
-  bool rows_set; /* not set means 'NULL' should be printed */
   ha_rows rows;
-
-  bool filtered_set; /* not set means 'NULL' should be printed */
   double filtered;
 
   /* 
@@ -604,19 +608,11 @@ class Explain_table_access : public Sql_alloc
   // Valid if ET_USING tag is present
   Explain_quick_select *quick_info;
 
-  // Valid if ET_USING_INDEX_FOR_GROUP_BY is present
-  bool loose_scan_is_scanning;
-  
   // valid with ET_RANGE_CHECKED_FOR_EACH_RECORD
   key_map range_checked_map;
 
-  // valid with ET_USING_MRR
-  StringBuffer<32> mrr_type;
-
   // valid with ET_USING_JOIN_BUFFER
   EXPLAIN_BKA_TYPE bka_type;
-  
-  StringBuffer<32> firstmatch_table_name;
 
   bool start_dups_weedout;
   bool end_dups_weedout;
@@ -633,6 +629,12 @@ class Explain_table_access : public Sql_alloc
 
   Explain_basic_join *sjm_nest;
 
+  /* ANALYZE members */
+
+  /* Tracker for reading the table */
+  Table_access_tracker tracker;
+  Table_access_tracker jbuf_tracker;
+
   int print_explain(select_result_sink *output, uint8 explain_flags, 
                     bool is_analyze,
                     uint select_id, const char *select_type,
@@ -640,12 +642,6 @@ class Explain_table_access : public Sql_alloc
   void print_explain_json(Explain_query *query, Json_writer *writer,
                           bool is_analyze);
 
-  /* ANALYZE members */
-
-  /* Tracker for reading the table */
-  Table_access_tracker tracker;
-  Table_access_tracker jbuf_tracker;
-
 private:
   void append_tag_name(String *str, enum explain_extra_tag tag);
   void fill_key_str(String *key_str, bool is_json) const;
@@ -665,6 +661,11 @@ class Explain_table_access : public Sql_alloc
 class Explain_update : public Explain_node
 {
 public:
+
+  Explain_update(MEM_ROOT *root) : 
+  Explain_node(root)
+  {}
+
   virtual enum explain_node_type get_type() { return EXPLAIN_UPDATE; }
   virtual int get_select_id() { return 1; /* always root */ }
 
@@ -719,6 +720,10 @@ class Explain_update : public Explain_node
 class Explain_insert : public Explain_node
 {
 public:
+  Explain_insert(MEM_ROOT *root) : 
+  Explain_node(root)
+  {}
+
   StringBuffer<64> table_name;
 
   enum explain_node_type get_type() { return EXPLAIN_INSERT; }
@@ -738,6 +743,10 @@ class Explain_insert : public Explain_node
 class Explain_delete: public Explain_update
 {
 public:
+  Explain_delete(MEM_ROOT *root) : 
+  Explain_update(root)
+  {}
+
   /*
     TRUE means we're going to call handler->delete_all_rows() and not read any
     rows.

sql/sql_insert.cc

@@ -612,7 +612,7 @@ create_insert_stmt_from_insert_delayed(THD *thd, String *buf)
 
 static void save_insert_query_plan(THD* thd, TABLE_LIST *table_list)
 {
-  Explain_insert* explain= new Explain_insert;
+  Explain_insert* explain= new (thd->mem_root) Explain_insert(thd->mem_root);
   explain->table_name.append(table_list->table->alias);
 
   thd->lex->explain->add_insert_plan(explain);

sql/sql_lex.cc

@@ -4253,7 +4253,7 @@ void LEX::restore_set_statement_var()
 int st_select_lex_unit::save_union_explain(Explain_query *output)
 {
   SELECT_LEX *first= first_select();
-  Explain_union *eu= new (output->mem_root) Explain_union;
+  Explain_union *eu= new (output->mem_root) Explain_union(output->mem_root);
 
   if (derived)
     eu->connection_type= Explain_node::EXPLAIN_NODE_DERIVED;

sql/sql_select.cc

@@ -3413,23 +3413,29 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
   LINT_INIT(table); /* inited in all loops */
   table_count=join->table_count;
 
-  stat=(JOIN_TAB*) join->thd->calloc(sizeof(JOIN_TAB)*(table_count));
-  stat_ref=(JOIN_TAB**) join->thd->alloc(sizeof(JOIN_TAB*)*
-                                         (MAX_TABLES + table_count + 1));
-  stat_vector= stat_ref + MAX_TABLES;
-  table_vector=(TABLE**) join->thd->calloc(sizeof(TABLE*)*(table_count*2));
-  join->positions= new (join->thd->mem_root) POSITION[(table_count+1)];
   /*
     best_positions is ok to allocate with alloc() as we copy things to it with
     memcpy()
   */
-  join->best_positions= (POSITION*) join->thd->alloc(sizeof(POSITION)*
-                                                     (table_count +1));
 
-  if (join->thd->is_fatal_error)
-    DBUG_RETURN(1);				// Eom /* purecov: inspected */
+  if (!multi_alloc_root(join->thd->mem_root,
+                        &stat, sizeof(JOIN_TAB)*(table_count),
+                        &stat_ref, sizeof(JOIN_TAB*)* MAX_TABLES,
+                        &stat_vector, sizeof(JOIN_TAB*)* (table_count +1),
+                        &table_vector, sizeof(TABLE*)*(table_count*2),
+                        &join->positions, sizeof(POSITION)*(table_count + 1),
+                        &join->best_positions,
+                        sizeof(POSITION)*(table_count + 1),
+                        NullS))
+    DBUG_RETURN(1);
+
+  /* The following should be optimized to only clear critical things */
+  bzero(stat, sizeof(JOIN_TAB)* table_count);
+  /* Initialize POSITION objects */
+  for (i=0 ; i <= table_count ; i++)
+    (void) new ((char*) (join->positions + i)) POSITION;
 
-  join->best_ref=stat_vector;
+  join->best_ref= stat_vector;
 
   stat_end=stat+table_count;
   found_const_table_map= all_table_map=0;
@@ -23267,15 +23273,18 @@ int append_possible_keys(MEM_ROOT *alloc, String_list &list, TABLE *table,
   return 0;
 }
 
-// TODO: this function is only applicable for the first non-const optimization
-// join tab. 
+/*
+  TODO: this function is only applicable for the first non-const optimization
+  join tab. 
+*/
+
 void JOIN_TAB::update_explain_data(uint idx)
 {
   if (this == first_breadth_first_tab(join, WALK_OPTIMIZATION_TABS) + join->const_tables &&
       join->select_lex->select_number != INT_MAX &&
       join->select_lex->select_number != UINT_MAX)
   {
-    Explain_table_access *eta= new Explain_table_access();
+    Explain_table_access *eta= new (join->thd->mem_root) Explain_table_access(join->thd->mem_root);
     JOIN_TAB* const first_top_tab= first_breadth_first_tab(join, WALK_OPTIMIZATION_TABS);
     save_explain_data(eta, join->const_table_map, join->select_distinct, first_top_tab);
 
@@ -23721,7 +23730,7 @@ int JOIN::save_explain_data_intern(Explain_query *output, bool need_tmp_table,
   if (message)
   {
     Explain_select *xpl_sel;
-    explain_node= xpl_sel= new (output->mem_root) Explain_select;
+    explain_node= xpl_sel= new (output->mem_root) Explain_select(output->mem_root);
     join->select_lex->set_explain_type(true);
 
     xpl_sel->select_id= join->select_lex->select_number;
@@ -23740,7 +23749,7 @@ int JOIN::save_explain_data_intern(Explain_query *output, bool need_tmp_table,
            join->select_lex->master_unit()->derived->is_materialized_derived())
   {
     Explain_select *xpl_sel;
-    explain_node= xpl_sel= new (output->mem_root) Explain_select;
+    explain_node= xpl_sel= new (output->mem_root) Explain_select(output->mem_root);
     table_map used_tables=0;
 
     join->select_lex->set_explain_type(true);
@@ -23781,7 +23790,8 @@ int JOIN::save_explain_data_intern(Explain_query *output, bool need_tmp_table,
         tab= pre_sort_join_tab;
       }
 
-      Explain_table_access *eta= new (output->mem_root) Explain_table_access;
+      Explain_table_access *eta= (new (output->mem_root)
+                                  Explain_table_access(output->mem_root));
 
       if (tab->bush_root_tab != prev_bush_root_tab)
       {
@@ -23790,7 +23800,7 @@ int JOIN::save_explain_data_intern(Explain_query *output, bool need_tmp_table,
           /* 
             We've entered an SJ-Materialization nest. Create an object for it.
           */
-          cur_parent= new Explain_basic_join;
+          cur_parent= new (output->mem_root) Explain_basic_join(output->mem_root);
 
           JOIN_TAB *first_child= tab->bush_root_tab->bush_children->start;
           cur_parent->select_id=
@@ -23809,7 +23819,7 @@ int JOIN::save_explain_data_intern(Explain_query *output, bool need_tmp_table,
       }
       prev_bush_root_tab= tab->bush_root_tab;
 
-      cur_parent->add_table(eta);
+      cur_parent->add_table(eta, output);
       tab->save_explain_data(eta, used_tables, distinct, first_top_tab);
 
       if (saved_join_tab)

sql/sql_select.h

@@ -785,7 +785,7 @@ class Sj_materialization_picker : public Semi_join_strategy_picker
   Information about a position of table within a join order. Used in join
   optimization.
 */
-typedef struct st_position :public Sql_alloc
+typedef struct st_position
 {
   /* The table that's put into join order */
   JOIN_TAB *table;