Merge bb-10.1-explain-analyze into 10.1

mysql-test/r/analyze_stmt.result

+drop table if exists t0,t1,t2,t3;
+create table t0 (a int) engine=myisam;
+INSERT INTO t0 VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table t1 (a int) engine=myisam;
+INSERT INTO t1 select * from t0;
+# Try a few basic selects to see that r_rows and r_filtered columns work
+analyze select * from t1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10	100.00	100.00	
+analyze select * from t1 where a<5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10	100.00	50.00	Using where
+analyze select * from t1 where a>100;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10	100.00	0.00	Using where
+# ANALYZE DELETE will delete rows:
+analyze delete from t1 where a in (2,3,4);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	NULL	100.00	30.00	Using where
+select * from t1;
+a
+0
+1
+5
+6
+7
+8
+9
+drop table t1;
+# ANALYZE UPDATE will make updates:
+create table t1(a int, b int);
+insert into t1 select a,a from t0;
+analyze update t1 set b=100+b where a in (6,7,8);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	NULL	100.00	30.00	Using where
+select * from t1;
+a	b
+0	0
+1	1
+2	2
+3	3
+4	4
+5	5
+6	106
+7	107
+8	108
+9	9
+drop table t1;
+# Check that UNION works
+create table t1(a int, b int);
+insert into t1 select a,a from t0;
+analyze (select * from t1 A where a<5) union (select * from t1 B where a in (5,6));
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	10	10	100.00	50.00	Using where
+2	UNION	B	ALL	NULL	NULL	NULL	NULL	10	10	100.00	20.00	Using where
+NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	7	NULL	NULL	
+analyze (select * from t1 A where a<5) union (select * from t1 B where a in (1,2));
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	PRIMARY	A	ALL	NULL	NULL	NULL	NULL	10	10	100.00	50.00	Using where
+2	UNION	B	ALL	NULL	NULL	NULL	NULL	10	10	100.00	20.00	Using where
+NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	5	NULL	NULL	
+drop table t1;
+drop table t0;
+# 
+# Try a subquery.
+# 
+create table t0 (a int, b int);
+insert into t0 values
+(0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+create table t1 (a int, b int);
+insert into t1 values (1,1),(2,2),(3,3);
+# See .test file for the right values of r_rows and r_filtered.
+analyze select a, a in (select t0.b from t0 where t0.b+1=t1.b+1) from t1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	3	100.00	100.00	
+2	DEPENDENT SUBQUERY	t0	ALL	NULL	NULL	NULL	NULL	10	3	100.00	33.33	Using where
+# Try a subquery that is never executed
+analyze select a, a in (select t0.b from t0 where t0.b+1=t1.b+1) from t1 where t1.a > 5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	3	100.00	0.00	Using where
+2	DEPENDENT SUBQUERY	t0	ALL	NULL	NULL	NULL	NULL	10	NULL	100.00	NULL	Using where
+drop table t0, t1;
+#
+# Tests for join buffering
+#
+create table t0 (a int, b int);
+insert into t0 values
+(0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+create table t1 like t0;
+insert into t1 select * from t0;
+explain select * from t0, t1 where t0.a<5 and t1.a<5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	10	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
+# These should have filtered=50
+analyze select * from t0, t1 where t0.a<5 and t1.a<5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	10	10	100.00	50.00	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10	100.00	50.00	Using where; Using join buffer (flat, BNL join)
+explain select * from t0, t1 where t0.a<5 and t1.b=t0.b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	10	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
+# Now, t1 should have filtered=10
+analyze select * from t0, t1 where t0.a<5 and t1.b=t0.b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	10	10	100.00	50.00	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10	100.00	10.00	Using where; Using join buffer (flat, BNL join)
+explain select * from t0, t1 where t0.a<5 and t1.a<5 and t1.b=t0.b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	10	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
+# Now, t1 should have filtered=10
+analyze select * from t0, t1 where t0.a<5 and t1.a<5 and t1.b=t0.b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	10	10	100.00	50.00	Using where
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10	100.00	10.00	Using where; Using join buffer (flat, BNL join)
+# TODO: Check what is counted for "range checked for each record".
+#
+# Test for joins
+#
+create table t2 (key1 int, key2x int, col1 int, key(key1), key(key2x));
+insert into t2 select A.a + 10 *B.a +100 * C.a, 
+(A.a + 10 *B.a +100 * C.a)*2,
+A.a + 10 *B.a +100 * C.a 
+from t0 A, t0 B, t0 C;
+# This always has matches, filtered=100%.
+analyze select * from t1,t2 where t2.key1=t1.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10	100.00	100.00	Using where
+1	SIMPLE	t2	ref	key1	key1	5	test.t1.a	1	1	100.00	100.00	
+# This shows r_rows=0. It is actually 0.5 (should r_rows be changed to double?)
+analyze select * from t1,t2 where t2.key2x=t1.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10	100.00	100.00	Using where
+1	SIMPLE	t2	ref	key2x	key2x	5	test.t1.a	1	0	100.00	100.00	
+select * from t1,t2 where t2.key2x=t1.a;
+a	b	key1	key2x	col1
+0	0	0	0	0
+2	2	1	2	1
+4	4	2	4	2
+6	6	3	6	3
+8	8	4	8	4
+# This has t2.filtered=40% (there are 5 values: {0,1,2,3,4}. two of them have mod=0)
+analyze select * from t1,t2 where t2.key2x=t1.a and mod(t2.col1,4)=0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	10	100.00	100.00	Using where
+1	SIMPLE	t2	ref	key2x	key2x	5	test.t1.a	1	0	100.00	40.00	Using where
+drop table t0,t1,t2;

mysql-test/r/ps.result

 call mtr.add_suppression('Unsafe statement written to the binary log using statement format since BINLOG_FORMAT = STATEMENT.');
 drop table if exists t1,t2,t3,t4;
+drop database if exists mysqltest1;
 drop database if exists client_test_db;
 create table t1
 (

mysql-test/r/show_explain.result

@@ -641,7 +641,7 @@ set debug_dbug='+d,show_explain_probe_join_exec_start';
 SHOW INDEX FROM t1;
 show explain for $thr2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	STATISTICS	ALL	NULL	NULL	NULL	NULL	NULL	Skip_open_table; Scanned all databases
+1	SIMPLE	STATISTICS	ALL	NULL	TABLE_SCHEMA,TABLE_NAME	NULL	NULL	NULL	Open_full_table; Scanned 0 databases
 Warnings:
 Note	1003	SHOW INDEX FROM t1
 Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment

mysql-test/t/analyze_stmt.test

+#
+#  Tests for "ANALYZE $statement" feature (PostgreSQL's analog is called EXPLAIN ANALYZE)
+#
+--disable_warnings
+drop table if exists t0,t1,t2,t3;
+--enable_warnings
+
+create table t0 (a int) engine=myisam;
+INSERT INTO t0 VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+
+create table t1 (a int) engine=myisam;
+INSERT INTO t1 select * from t0;
+
+--echo # Try a few basic selects to see that r_rows and r_filtered columns work
+analyze select * from t1;
+analyze select * from t1 where a<5;
+analyze select * from t1 where a>100;
+
+--echo # ANALYZE DELETE will delete rows:
+analyze delete from t1 where a in (2,3,4);
+select * from t1;
+drop table t1;
+
+--echo # ANALYZE UPDATE will make updates:
+create table t1(a int, b int);
+insert into t1 select a,a from t0;
+analyze update t1 set b=100+b where a in (6,7,8);
+select * from t1;
+drop table t1;
+
+--echo # Check that UNION works
+create table t1(a int, b int);
+insert into t1 select a,a from t0;
+analyze (select * from t1 A where a<5) union (select * from t1 B where a in (5,6));
+analyze (select * from t1 A where a<5) union (select * from t1 B where a in (1,2));
+drop table t1;
+drop table t0;
+
+--echo # 
+--echo # Try a subquery.
+--echo # 
+create table t0 (a int, b int);
+insert into t0 values
+  (0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+
+create table t1 (a int, b int);
+insert into t1 values (1,1),(2,2),(3,3);
+
+#
+#   t1      t0
+#   a=1     (0,1)       2 rows
+#   a=2     (0,1,2)     3 rows
+#   a=3     (0,1,2,3)   4 rows
+#
+#  TOTAL    TOTAL= 9 rows.  3 executions, avg=3 rows.
+#  WHERE is satisfied for 1 row per query, which gives filtered=33.3
+
+--echo # See .test file for the right values of r_rows and r_filtered.
+analyze select a, a in (select t0.b from t0 where t0.b+1=t1.b+1) from t1;
+
+--echo # Try a subquery that is never executed
+analyze select a, a in (select t0.b from t0 where t0.b+1=t1.b+1) from t1 where t1.a > 5;
+
+drop table t0, t1;
+
+--echo #
+--echo # Tests for join buffering
+--echo #
+create table t0 (a int, b int);
+insert into t0 values
+  (0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+create table t1 like t0;
+insert into t1 select * from t0;
+
+explain select * from t0, t1 where t0.a<5 and t1.a<5;
+--echo # These should have filtered=50
+analyze select * from t0, t1 where t0.a<5 and t1.a<5;
+
+explain select * from t0, t1 where t0.a<5 and t1.b=t0.b;
+--echo # Now, t1 should have filtered=10
+analyze select * from t0, t1 where t0.a<5 and t1.b=t0.b;
+
+explain select * from t0, t1 where t0.a<5 and t1.a<5 and t1.b=t0.b;
+--echo # Now, t1 should have filtered=10
+analyze select * from t0, t1 where t0.a<5 and t1.a<5 and t1.b=t0.b;
+
+--echo # TODO: Check what is counted for "range checked for each record".
+
+--echo #
+--echo # Test for joins
+--echo #
+create table t2 (key1 int, key2x int, col1 int, key(key1), key(key2x));
+insert into t2 select A.a + 10 *B.a +100 * C.a, 
+                      (A.a + 10 *B.a +100 * C.a)*2,
+                      A.a + 10 *B.a +100 * C.a 
+               from t0 A, t0 B, t0 C;
+
+--echo # This always has matches, filtered=100%.
+analyze select * from t1,t2 where t2.key1=t1.a;
+
+--echo # This shows r_rows=0. It is actually 0.5 (should r_rows be changed to double?)
+analyze select * from t1,t2 where t2.key2x=t1.a;
+        select * from t1,t2 where t2.key2x=t1.a;
+
+--echo # This has t2.filtered=40% (there are 5 values: {0,1,2,3,4}. two of them have mod=0)
+analyze select * from t1,t2 where t2.key2x=t1.a and mod(t2.col1,4)=0;
+
+drop table t0,t1,t2;
+

mysql-test/t/ps.test

@@ -7,6 +7,7 @@ call mtr.add_suppression('Unsafe statement written to the binary log using state
 --disable_warnings
 drop table if exists t1,t2,t3,t4;
 
+drop database if exists mysqltest1;
 # Avoid wrong warnings if mysql_client_test fails
 drop database if exists client_test_db;
 --enable_warnings

sql/protocol.h

@@ -210,6 +210,42 @@ class Protocol_binary :public Protocol
   virtual enum enum_protocol_type type() { return PROTOCOL_BINARY; };
 };
 
+
+/*
+  A helper for "ANALYZE $stmt" which looks a real network procotol but doesn't
+  write results to the network.
+
+  At first glance, class select_send looks like a more appropriate place to
+  implement the "write nothing" hook. This is not true, because
+    - we need to evaluate the value of every item, and do it the way
+      select_send does it (i.e. call item->val_int() or val_real() or...)
+    - select_send::send_data() has some other code, like telling the storage
+      engine that the row can be unlocked. We want to keep that also.
+  as a result, "ANALYZE $stmt" uses a select_send_analyze which still uses 
+  select_send::send_data() & co., and also uses  Protocol_discard object.
+*/
+
+class Protocol_discard : public Protocol_text
+{
+public:
+  Protocol_discard(THD *thd_arg) : Protocol_text(thd_arg) {}
+  /* The real writing is done only in write() */
+  virtual bool write() { return 0; }
+  virtual bool send_result_set_metadata(List<Item> *list, uint flags)
+  {
+    // Don't pas Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF flags 
+    return Protocol_text::send_result_set_metadata(list, 0);
+  }
+
+  // send_error is intentionally not overloaded.
+  virtual bool send_eof(uint server_status, uint statement_warn_count)
+  {
+    return 0;
+  }
+
+};
+
+
 void send_warning(THD *thd, uint sql_errno, const char *err=0);
 bool net_send_error(THD *thd, uint sql_errno, const char *err,
                     const char* sqlstate);

sql/sql_class.cc

@@ -2282,6 +2282,9 @@ int THD::send_explain_fields(select_result *result)
 /*
   Populate the provided field_list with EXPLAIN output columns.
   this->lex->describe has the EXPLAIN flags
+
+  The set/order of columns must be kept in sync with 
+  Explain_query::print_explain and co.
 */
 
 void THD::make_explain_field_list(List<Item> &field_list)
@@ -2317,11 +2320,25 @@ void THD::make_explain_field_list(List<Item> &field_list)
   item->maybe_null=1;
   field_list.push_back(item= new Item_return_int("rows", 10,
                                                  MYSQL_TYPE_LONGLONG));
-  if (lex->describe & DESCRIBE_EXTENDED)
+  if (lex->analyze_stmt)
+  {
+    field_list.push_back(item= new Item_return_int("r_rows", 10,
+                                                   MYSQL_TYPE_LONGLONG));
+    item->maybe_null=1;
+  }
+
+  if (lex->analyze_stmt || lex->describe & DESCRIBE_EXTENDED)
   {
     field_list.push_back(item= new Item_float("filtered", 0.1234, 2, 4));
     item->maybe_null=1;
   }
+
+  if (lex->analyze_stmt)
+  {
+    field_list.push_back(item= new Item_float("r_filtered", 0.1234, 2, 4));
+    item->maybe_null=1;
+  }
+
   item->maybe_null= 1;
   field_list.push_back(new Item_empty_string("Extra", 255, cs));
 }

sql/sql_class.h

@@ -3961,6 +3961,20 @@ class select_send :public select_result {
 };
 
 
+/*
+  We need this class, because select_send::send_eof() will call ::my_eof.
+
+  See also class Protocol_discard.
+*/
+
+class select_send_analyze : public select_send
+{
+  bool send_result_set_metadata(List<Item> &list, uint flags) { return 0; }
+  bool send_eof() { return 0; }
+  void abort_result_set() {}
+};
+
+
 class select_to_file :public select_result_interceptor {
 protected:
   sql_exchange *exchange;

sql/sql_delete.cc

@@ -223,6 +223,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   killed_state killed_status= NOT_KILLED;
   THD::enum_binlog_query_type query_type= THD::ROW_QUERY_TYPE;
   bool with_select= !select_lex->item_list.is_empty();
+  Explain_delete *explain;
   Delete_plan query_plan(thd->mem_root);
   query_plan.index= MAX_KEY;
   query_plan.using_filesort= FALSE;
@@ -538,9 +539,11 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
       goto cleanup;
   }
 
+  explain= (Explain_delete*)thd->lex->explain->get_upd_del_plan();
   while (!(error=info.read_record(&info)) && !thd->killed &&
 	 ! thd->is_error())
   {
+    explain->on_record_read();
     if (table->vfield)
       update_virtual_fields(thd, table,
                             table->triggers ? VCOL_UPDATE_ALL :
@@ -549,6 +552,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
     // thd->is_error() is tested to disallow delete row on error
     if (!select || select->skip_record(thd) > 0)
     {
+      explain->on_record_after_where();
       if (table->triggers &&
           table->triggers->process_triggers(thd, TRG_EVENT_DELETE,
                                             TRG_ACTION_BEFORE, FALSE))
@@ -666,6 +670,11 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   }
   DBUG_ASSERT(transactional_table || !deleted || thd->transaction.stmt.modified_non_trans_table);
   free_underlaid_joins(thd, select_lex);
+  if (thd->lex->analyze_stmt)
+  {
+    error= thd->lex->explain->send_explain(thd);
+  }
+  else
   if (error < 0 || 
       (thd->lex->ignore && !thd->is_error() && !thd->is_fatal_error))
   {

sql/sql_explain.h

@@ -14,6 +14,38 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
+/* Data structures for ANALYZE */
+class Table_access_tracker 
+{
+public:
+  Table_access_tracker() :
+    r_scans(0), r_rows(0), /*r_rows_after_table_cond(0),*/
+    r_rows_after_where(0)
+  {}
+
+  ha_rows r_scans; /* How many scans were ran on this join_tab */
+  ha_rows r_rows; /* How many rows we've got after that */
+//  ha_rows r_rows_after_table_cond; /* Rows after applying the table condition */
+  ha_rows r_rows_after_where; /* Rows after applying attached part of WHERE */
+
+  bool has_scans() { return (r_scans != 0); }
+  ha_rows get_avg_rows()
+  {
+    return r_scans ? (ha_rows)rint((double) r_rows / r_scans): 0;
+  }
+
+  double get_filtered_after_where()
+  {
+    double r_filtered;
+    if (r_rows > 0)
+      r_filtered= (double)r_rows_after_where / r_rows;
+    else
+      r_filtered= 1.0;
+
+    return r_filtered;
+  }
+};
+
 
 /**************************************************************************************
  
@@ -60,10 +92,10 @@ class Explain_node : public Sql_alloc
   }
 
   virtual int print_explain(Explain_query *query, select_result_sink *output, 
-                            uint8 explain_flags)=0;
+                            uint8 explain_flags, bool is_analyze)=0;
   
   int print_explain_for_children(Explain_query *query, select_result_sink *output, 
-                                 uint8 explain_flags);
+                                 uint8 explain_flags, bool is_analyze);
   virtual ~Explain_node(){}
 };
 
@@ -110,6 +142,12 @@ class Explain_select : public Explain_node
     return false;
   }
   
+  /*
+    This is used to save the results of "late" test_if_skip_sort_order() calls
+    that are made from JOIN::exec
+  */
+  void replace_table(uint idx, Explain_table_access *new_tab);
+
 public:
   int select_id;
   const char *select_type;
@@ -134,7 +172,14 @@ class Explain_select : public Explain_node
   bool using_filesort;
   
   int print_explain(Explain_query *query, select_result_sink *output, 
-                    uint8 explain_flags);
+                    uint8 explain_flags, bool is_analyze);
+  
+  Table_access_tracker *get_using_temporary_read_tracker()
+  {
+    return &using_temporary_read_tracker;
+  }
+private:
+  Table_access_tracker using_temporary_read_tracker;
 };
 
 
@@ -172,10 +217,23 @@ class Explain_union : public Explain_node
     union_members.append(select_no);
   }
   int print_explain(Explain_query *query, select_result_sink *output, 
-                    uint8 explain_flags);
+                    uint8 explain_flags, bool is_analyze);
 
   const char *fake_select_type;
   bool using_filesort;
+
+  Table_access_tracker *get_fake_select_lex_tracker()
+  {
+    return &fake_select_lex_tracker;
+  }
+  Table_access_tracker *get_tmptable_read_tracker()
+  {
+    return &tmptable_read_tracker;
+  }
+private:
+  Table_access_tracker fake_select_lex_tracker;
+  /* This one is for reading after ORDER BY */
+  Table_access_tracker tmptable_read_tracker; 
 };
 
 
@@ -183,6 +241,7 @@ class Explain_update;
 class Explain_delete;
 class Explain_insert;
 
+
 /*
   Explain structure for a query (i.e. a statement).
 
@@ -238,13 +297,14 @@ class Explain_query : public Sql_alloc
   Explain_union *get_union(uint select_id);
  
   /* Produce a tabular EXPLAIN output */
-  int print_explain(select_result_sink *output, uint8 explain_flags);
+  int print_explain(select_result_sink *output, uint8 explain_flags, 
+                    bool is_analyze);
   
   /* Send tabular EXPLAIN to the client */
   int send_explain(THD *thd);
   
   /* Return tabular EXPLAIN output as a text string */
-  bool print_explain_str(THD *thd, String *out_str);
+  bool print_explain_str(THD *thd, String *out_str, bool is_analyze);
 
   /* If true, at least part of EXPLAIN can be printed */
   bool have_query_plan() { return insert_plan || upd_del_plan|| get_node(1) != NULL; }
@@ -252,6 +312,8 @@ class Explain_query : public Sql_alloc
   void query_plan_ready();
 
   MEM_ROOT *mem_root;
+
+  Explain_update *get_upd_del_plan() { return upd_del_plan; }
 private:
   /* Explain_delete inherits from Explain_update */
   Explain_update *upd_del_plan;
@@ -320,13 +382,17 @@ enum explain_extra_tag
 };
 
 
-typedef struct st_explain_bka_type
+class EXPLAIN_BKA_TYPE
 {
+public:
+  EXPLAIN_BKA_TYPE() : join_alg(NULL) {}
+
   bool incremental;
   const char *join_alg;
   StringBuffer<64> mrr_type;
   
-} EXPLAIN_BKA_TYPE;
+  bool is_using_jbuf() { return (join_alg != NULL); }
+};
 
 
 /*
@@ -386,6 +452,7 @@ class Explain_quick_select : public Sql_alloc
 /*
   EXPLAIN data structure for a single JOIN_TAB.
 */
+
 class Explain_table_access : public Sql_alloc
 {
 public:
@@ -459,8 +526,14 @@ class Explain_table_access : public Sql_alloc
   StringBuffer<32> firstmatch_table_name;
 
   int print_explain(select_result_sink *output, uint8 explain_flags, 
+                    bool is_analyze,
                     uint select_id, const char *select_type,
                     bool using_temporary, bool using_filesort);
+
+  /* ANALYZE members*/
+  Table_access_tracker tracker;
+  Table_access_tracker jbuf_tracker;
+
 private:
   void append_tag_name(String *str, enum explain_extra_tag tag);
 };
@@ -502,8 +575,17 @@ class Explain_update : public Explain_node
   bool using_filesort;
   bool using_io_buffer;
 
+  /* ANALYZE members and methods */
+  ha_rows r_rows;
+  ha_rows r_rows_after_where;
+  inline void on_record_read() { r_rows++; }
+  inline void on_record_after_where() { r_rows_after_where++; }
+
+  Explain_update() : 
+    r_rows(0), r_rows_after_where(0)
+  {}
   virtual int print_explain(Explain_query *query, select_result_sink *output, 
-                            uint8 explain_flags);
+                            uint8 explain_flags, bool is_analyze);
 };
 
 
@@ -523,7 +605,7 @@ class Explain_insert : public Explain_node
   int get_select_id() { return 1; /* always root */ }
 
   int print_explain(Explain_query *query, select_result_sink *output, 
-                    uint8 explain_flags);
+                    uint8 explain_flags, bool is_analyze);
 };
 
 
@@ -544,7 +626,7 @@ class Explain_delete: public Explain_update
   virtual int get_select_id() { return 1; /* always root */ }
 
   virtual int print_explain(Explain_query *query, select_result_sink *output, 
-                            uint8 explain_flags);
+                            uint8 explain_flags, bool is_analyze);
 };
 
 

sql/sql_join_cache.cc

@@ -2277,11 +2277,13 @@ enum_nested_loop_state JOIN_CACHE::join_matching_records(bool skip_last)
     /* Prepare to read matching candidates from the join buffer */
     if (prepare_look_for_matches(skip_last))
       continue;
+    join_tab->jbuf_tracker->r_scans++;
 
     uchar *rec_ptr;
     /* Read each possible candidate from the buffer and look for matches */
     while ((rec_ptr= get_next_candidate_for_match()))
     {
+      join_tab->jbuf_tracker->r_rows++;
       /* 
         If only the first match is needed, and, it has been already found for
         the next record read from the join buffer, then the record is skipped.
@@ -2452,6 +2454,8 @@ inline bool JOIN_CACHE::check_match(uchar *rec_ptr)
   if (join_tab->select && join_tab->select->skip_record(join->thd) <= 0)
     DBUG_RETURN(FALSE);
   
+  join_tab->jbuf_tracker->r_rows_after_where++;
+
   if (!join_tab->is_last_inner_table())
     DBUG_RETURN(TRUE);
 
@@ -2574,7 +2578,7 @@ enum_nested_loop_state JOIN_CACHE::join_null_complements(bool skip_last)
     none
 */ 
 
-void JOIN_CACHE::save_explain_data(struct st_explain_bka_type *explain)
+void JOIN_CACHE::save_explain_data(EXPLAIN_BKA_TYPE *explain)
 {
   explain->incremental= MY_TEST(prev_cache);
 
@@ -2619,14 +2623,14 @@ static void add_mrr_explain_info(String *str, uint mrr_mode, handler *file)
   }
 }
 
-void JOIN_CACHE_BKA::save_explain_data(struct st_explain_bka_type *explain)
+void JOIN_CACHE_BKA::save_explain_data(EXPLAIN_BKA_TYPE *explain)
 {
   JOIN_CACHE::save_explain_data(explain); 
   add_mrr_explain_info(&explain->mrr_type, mrr_mode, join_tab->table->file);
 }
 
 
-void JOIN_CACHE_BKAH::save_explain_data(struct st_explain_bka_type *explain)
+void JOIN_CACHE_BKAH::save_explain_data(EXPLAIN_BKA_TYPE *explain)
 {
   JOIN_CACHE::save_explain_data(explain); 
   add_mrr_explain_info(&explain->mrr_type, mrr_mode, join_tab->table->file);
@@ -3333,6 +3337,7 @@ int JOIN_TAB_SCAN::open()
 {
   save_or_restore_used_tabs(join_tab, FALSE);
   is_first_record= TRUE;
+  join_tab->tracker->r_scans++;
   return join_init_read_record(join_tab);
 }
 
@@ -3371,8 +3376,14 @@ int JOIN_TAB_SCAN::next()
     is_first_record= FALSE;
   else
     err= info->read_record(info);
-  if (!err && table->vfield)
+
+  if (!err)
+  {
+    join_tab->tracker->r_rows++;
+    if (table->vfield)
       update_virtual_fields(thd, table);
+  }
+
   while (!err && select && (skip_rc= select->skip_record(thd)) <= 0)
   {
     if (thd->check_killed() || skip_rc < 0) 
@@ -3382,9 +3393,16 @@ int JOIN_TAB_SCAN::next()
       meet the condition pushed to the table join_tab.
     */
     err= info->read_record(info);
-    if (!err && table->vfield)
+    if (!err)
+    {
+      join_tab->tracker->r_rows++;
+      if (table->vfield)
         update_virtual_fields(thd, table);
     }
+  }
+
+  if (!err)
+    join_tab->tracker->r_rows_after_where++;
   return err; 
 }
 

sql/sql_join_cache.h

@@ -63,7 +63,7 @@ typedef struct st_cache_field {
 
 class JOIN_TAB_SCAN;
 
-struct st_explain_bka_type;
+class EXPLAIN_BKA_TYPE;
 
 /*
   JOIN_CACHE is the base class to support the implementations of 
@@ -662,7 +662,7 @@ class JOIN_CACHE :public Sql_alloc
   enum_nested_loop_state join_records(bool skip_last);
 
   /* Add a comment on the join algorithm employed by the join cache */
-  virtual void save_explain_data(struct st_explain_bka_type *explain);
+  virtual void save_explain_data(EXPLAIN_BKA_TYPE *explain);
 
   THD *thd();
 
@@ -1340,7 +1340,7 @@ class JOIN_CACHE_BKA :public JOIN_CACHE
   /* Check index condition of the joined table for a record from BKA cache */
   bool skip_index_tuple(range_id_t range_info);
 
-  void save_explain_data(struct st_explain_bka_type *explain);
+  void save_explain_data(EXPLAIN_BKA_TYPE *explain);
 };
 
 
@@ -1431,5 +1431,5 @@ class JOIN_CACHE_BKAH :public JOIN_CACHE_BNLH
   /* Check index condition of the joined table for a record from BKAH cache */
   bool skip_index_tuple(range_id_t range_info);
 
-  void save_explain_data(struct st_explain_bka_type *explain);
+  void save_explain_data(EXPLAIN_BKA_TYPE *explain);
 };

sql/sql_lex.cc

@@ -483,6 +483,7 @@ void lex_start(THD *thd)
   if (lex->select_lex.group_list_ptrs)
     lex->select_lex.group_list_ptrs->clear();
   lex->describe= 0;
+  lex->analyze_stmt= 0;
   lex->subqueries= FALSE;
   lex->context_analysis_only= 0;
   lex->derived_tables= 0;
@@ -4181,12 +4182,12 @@ bool st_select_lex::is_merged_child_of(st_select_lex *ancestor)
 */
 
 int LEX::print_explain(select_result_sink *output, uint8 explain_flags,
-                       bool *printed_anything)
+                       bool is_analyze, bool *printed_anything)
 {
   int res;
   if (explain && explain->have_query_plan())
   {
-    res= explain->print_explain(output, explain_flags);
+    res= explain->print_explain(output, explain_flags, is_analyze);
     *printed_anything= true;
   }
   else

sql/sql_lex.h

@@ -2268,6 +2268,7 @@ class Update_plan
 
   void save_explain_data(Explain_query *query);
   void save_explain_data_intern(Explain_query *query, Explain_update *eu);
+
   virtual ~Update_plan() {}
 
   Update_plan(MEM_ROOT *mem_root_arg) : 
@@ -2459,6 +2460,7 @@ struct LEX: public Query_tables_list
   */
   uint table_count;
   uint8 describe;
+  bool  analyze_stmt; /* TRUE<=> this is "ANALYZE $stmt" */
   /*
     A flag that indicates what kinds of derived tables are present in the
     query (0 if no derived tables, otherwise a combination of flags
@@ -2735,7 +2737,7 @@ struct LEX: public Query_tables_list
   }
 
   int print_explain(select_result_sink *output, uint8 explain_flags,
-                    bool *printed_anything);
+                    bool is_analyze, bool *printed_anything);
 };
 
 

sql/sql_parse.cc

@@ -5233,7 +5233,8 @@ static bool execute_sqlcom_select(THD *thd, TABLE_LIST *all_tables)
           top-level LIMIT
         */        
         result->reset_offset_limit(); 
-        thd->lex->explain->print_explain(result, thd->lex->describe);
+        thd->lex->explain->print_explain(result, thd->lex->describe,
+                                         thd->lex->analyze_stmt);
         if (lex->describe & DESCRIBE_EXTENDED)
         {
           char buff[1024];
@@ -5256,13 +5257,38 @@ static bool execute_sqlcom_select(THD *thd, TABLE_LIST *all_tables)
       delete result;
     }
     else
+    {
+      //psergey-todo: ANALYZE should hook in here...
+      select_result *save_result;
+      Protocol *save_protocol;
+      if (lex->analyze_stmt)
+      {
+        save_result= result;
+        result= new select_send_analyze();
+        save_protocol= thd->protocol;
+        thd->protocol= new Protocol_discard(thd);
+      }
+      else
       {
         if (!result && !(result= new select_send()))
           return 1;                               /* purecov: inspected */
+      }
       query_cache_store_query(thd, all_tables);
       res= handle_select(thd, lex, result, 0);
       if (result != lex->result)
         delete result;
+
+      if (lex->analyze_stmt)
+      {
+        result= save_result;
+        if (!result && !(result= new select_send()))
+          return 1;
+        thd->protocol= save_protocol;
+        thd->lex->explain->send_explain(thd);
+
+        if (result != lex->result)
+          delete result;
+      }
     }
   }
   /* Count number of empty select queries */

sql/sql_select.h

@@ -251,6 +251,8 @@ typedef struct st_join_table {
   /* Special content for EXPLAIN 'Extra' column or NULL if none */
   enum explain_extra_tag info;
   
+  Table_access_tracker *tracker;
+  Table_access_tracker *jbuf_tracker;
   /* 
     Bitmap of TAB_INFO_* bits that encodes special line for EXPLAIN 'Extra'
     column, or 0 if there is no info.
@@ -536,6 +538,11 @@ typedef struct st_join_table {
   }
 
   void remove_redundant_bnl_scan_conds();
+
+  void save_explain_data(Explain_table_access *eta, table_map prefix_tables, 
+                         bool distinct, struct st_join_table *first_top_tab);
+
+  void update_explain_data(uint idx);
 } JOIN_TAB;
 
 
@@ -1848,14 +1855,14 @@ void push_index_cond(JOIN_TAB *tab, uint keyno);
 
 /* EXPLAIN-related utility functions */
 int print_explain_message_line(select_result_sink *result, 
-                               uint8 options,
+                               uint8 options, bool is_analyze,
                                uint select_number,
                                const char *select_type,
                                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,
+                      uint8 options, bool is_analyze,
                       uint select_number,
                       const char *select_type,
                       const char *table_name,
@@ -1866,6 +1873,8 @@ int print_explain_row(select_result_sink *result,
                       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);
 

sql/sql_show.h

@@ -150,6 +150,69 @@ class Show_explain_request : public Apc_target::Apc_call
   void call_in_target_thread();
 };
 
+/**
+  Condition pushdown used for INFORMATION_SCHEMA / SHOW queries.
+  This structure is to implement an optimization when
+  accessing data dictionary data in the INFORMATION_SCHEMA
+  or SHOW commands.
+  When the query contain a TABLE_SCHEMA or TABLE_NAME clause,
+  narrow the search for data based on the constraints given.
+*/
+typedef struct st_lookup_field_values
+{
+  /**
+    Value of a TABLE_SCHEMA clause.
+    Note that this value length may exceed @c NAME_LEN.
+    @sa wild_db_value
+  */
+  LEX_STRING db_value;
+  /**
+    Value of a TABLE_NAME clause.
+    Note that this value length may exceed @c NAME_LEN.
+    @sa wild_table_value
+  */
+  LEX_STRING table_value;
+  /**
+    True when @c db_value is a LIKE clause,
+    false when @c db_value is an '=' clause.
+  */
+  bool wild_db_value;
+  /**
+    True when @c table_value is a LIKE clause,
+    false when @c table_value is an '=' clause.
+  */
+  bool wild_table_value;
+} LOOKUP_FIELD_VALUES;  
+
+
+/*
+  INFORMATION_SCHEMA: Execution plan for get_all_tables() call
+*/
+
+class IS_table_read_plan : public Sql_alloc
+{
+public:
+  IS_table_read_plan() : no_rows(false) {}
+
+  bool no_rows;
+
+  LOOKUP_FIELD_VALUES lookup_field_vals;
+  Item *partial_cond;
+
+  bool has_db_lookup_value()
+  {
+    return (lookup_field_vals.db_value.length &&
+           !lookup_field_vals.wild_db_value);
+  }
+  bool has_table_lookup_value()
+  {
+    return (lookup_field_vals.table_value.length &&
+            !lookup_field_vals.wild_table_value);
+  }
+};
+
+bool optimize_schema_tables_reads(JOIN *join);
+
 /* Handle the ignored database directories list for SHOW/I_S. */
 bool ignore_db_dirs_init();
 void ignore_db_dirs_free();

sql/sql_update.cc

@@ -277,6 +277,7 @@ int mysql_update(THD *thd,
   List<Item> all_fields;
   killed_state killed_status= NOT_KILLED;
   Update_plan query_plan(thd->mem_root);
+  Explain_update *explain;
   query_plan.index= MAX_KEY;
   query_plan.using_filesort= FALSE;
   DBUG_ENTER("mysql_update");
@@ -717,15 +718,16 @@ int mysql_update(THD *thd,
   if (table->file->ha_table_flags() & HA_PARTIAL_COLUMN_READ)
     table->prepare_for_position();
 
+  explain= thd->lex->explain->get_upd_del_plan();
   /*
     We can use compare_record() to optimize away updates if
     the table handler is returning all columns OR if
     if all updated columns are read
   */
   can_compare_record= records_are_comparable(table);
-
   while (!(error=info.read_record(&info)) && !thd->killed)
   {
+    explain->on_record_read();
     if (table->vfield)
       update_virtual_fields(thd, table,
                             table->triggers ? VCOL_UPDATE_ALL :
@@ -736,6 +738,7 @@ int mysql_update(THD *thd,
       if (table->file->was_semi_consistent_read())
         continue;  /* repeat the read of the same row if it still exists */
 
+      explain->on_record_after_where();
       store_record(table,record[1]);
       if (fill_record_n_invoke_before_triggers(thd, table, fields, values, 0,
                                                TRG_EVENT_UPDATE))
@@ -993,7 +996,11 @@ int mysql_update(THD *thd,
   id= thd->arg_of_last_insert_id_function ?
     thd->first_successful_insert_id_in_prev_stmt : 0;
 
-  if (error < 0)
+  if (thd->lex->analyze_stmt)
+  {
+    error= thd->lex->explain->send_explain(thd);
+  }
+  else if (error < 0)
   {
     char buff[MYSQL_ERRMSG_SIZE];
     my_snprintf(buff, sizeof(buff), ER(ER_UPDATE_INFO), (ulong) found,

sql/sql_yacc.yy

@@ -1804,6 +1804,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 %type <dyncol_def_list> dyncall_create_list
 
 %type <NONE>
+        analyze_stmt_command
         query verb_clause create change select do drop insert replace insert2
         insert_values update delete truncate rename
         show describe load alter optimize keycache preload flush
@@ -1990,6 +1991,7 @@ verb_clause:
 statement:
           alter
         | analyze
+        | analyze_stmt_command
         | binlog_base64_event
         | call
         | change
@@ -12766,6 +12768,13 @@ describe_command:
         | DESCRIBE
         ;
 
+analyze_stmt_command:
+          ANALYZE_SYM explainable_command
+          {
+            Lex->analyze_stmt= true;
+          }
+        ;
+
 opt_extended_describe:
           /* empty */ {}
         | EXTENDED_SYM   { Lex->describe|= DESCRIBE_EXTENDED; }

sql/table.h

@@ -1499,6 +1499,7 @@ typedef struct st_schema_table
   uint i_s_requested_object;  /* the object we need to open(TABLE | VIEW) */
 } ST_SCHEMA_TABLE;
 
+class IS_table_read_plan;
 
 /*
   Types of derived tables. The ending part is a bitmap of phases that are
@@ -2044,12 +2045,23 @@ struct TABLE_LIST
   /* TRUE <=> this table is a const one and was optimized away. */
   bool optimized_away;
 
+  /* I_S: Flags to open_table (e.g. OPEN_TABLE_ONLY or OPEN_VIEW_ONLY) */
   uint i_s_requested_object;
-  bool has_db_lookup_value;
-  bool has_table_lookup_value;
+
+  /*
+    I_S: how to read the tables (SKIP_OPEN_TABLE/OPEN_FRM_ONLY/OPEN_FULL_TABLE)
+  */
   uint table_open_method;
+  /*
+    I_S: where the schema table was filled
+    (this is a hack. The code should be able to figure out whether reading
+    from I_S should be done by create_sort_index() or by JOIN::exec.)
+  */
   enum enum_schema_table_state schema_table_state;
 
+  /* Something like a "query plan" for reading INFORMATION_SCHEMA table */
+  IS_table_read_plan *is_table_read_plan;
+
   MDL_request mdl_request;
 
 #ifdef WITH_PARTITION_STORAGE_ENGINE