Merge sanja.is.com.ua:/home/bell/mysql/mysql-4.1

into sanja.is.com.ua:/home/bell/mysql/work-distinct-4.1

mysql-test/r/subselect.result

@@ -54,9 +54,9 @@ explain select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1)
 union (select * from t4 where t4.b=(select max(t2.a)*4 from t2) order by a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	where used
+2	SUBSELECT	t3	ALL	NULL	NULL	NULL	NULL	3	Using filesort
 3	UNION	t4	ALL	NULL	NULL	NULL	NULL	3	where used; Using filesort
 4	SUBSELECT	t2	ALL	NULL	NULL	NULL	NULL	2	
-2	SUBSELECT	t3	ALL	NULL	NULL	NULL	NULL	3	Using filesort
 select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
 (select a from t3 where a<t2.a*4 order by 1 desc limit 1)	a
 3	1
@@ -163,9 +163,7 @@ UNIQUE KEY `email` (`email`)
 INSERT INTO inscrit (pseudo,email) VALUES ('joce','test');
 INSERT INTO inscrit (pseudo,email) VALUES ('joce1','test1');
 INSERT INTO inscrit (pseudo,email) VALUES ('2joce1','2test1');
-EXPLAIN SELECT pseudo,(SELECT email FROM inscrit WHERE pseudo=(SELECT
-pseudo FROM inscrit WHERE pseudo='joce')) FROM inscrit WHERE pseudo=(SELECT
-pseudo FROM inscrit WHERE pseudo='joce');
+EXPLAIN SELECT pseudo,(SELECT email FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce')) FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	inscrit	const	PRIMARY	PRIMARY	35	const	1	
 4	SUBSELECT	inscrit	const	PRIMARY	PRIMARY	35	const	1	
@@ -183,3 +181,21 @@ joce
 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo LIKE '%joce%');
 Subselect returns more than 1 record
 drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit;
+drop table if exists searchconthardwarefr3;
+CREATE TABLE `searchconthardwarefr3` (
+`topic` mediumint(8) unsigned NOT NULL default '0',
+`date` date NOT NULL default '0000-00-00',
+`pseudo` varchar(35) character set latin1 NOT NULL default '',
+PRIMARY KEY  (`pseudo`,`date`,`topic`),
+KEY `topic` (`topic`)
+) TYPE=MyISAM ROW_FORMAT=DYNAMIC;
+INSERT INTO searchconthardwarefr3 (topic,date,pseudo) VALUES
+('43506','2002-10-02','joce'),('40143','2002-08-03','joce');
+EXPLAIN SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	searchconthardwarefr3	index	NULL	PRIMARY	41	NULL	2	where used; Using index
+EXPLAIN SELECT (SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY								No tables used
+2	SUBSELECT	searchconthardwarefr3	index	NULL	PRIMARY	41	NULL	2	where used; Using index
+drop table searchconthardwarefr3;

mysql-test/t/subselect.test

@@ -83,9 +83,7 @@ CREATE TABLE `inscrit` (
 INSERT INTO inscrit (pseudo,email) VALUES ('joce','test');
 INSERT INTO inscrit (pseudo,email) VALUES ('joce1','test1');
 INSERT INTO inscrit (pseudo,email) VALUES ('2joce1','2test1');
-EXPLAIN SELECT pseudo,(SELECT email FROM inscrit WHERE pseudo=(SELECT
-pseudo FROM inscrit WHERE pseudo='joce')) FROM inscrit WHERE pseudo=(SELECT
-pseudo FROM inscrit WHERE pseudo='joce');
+EXPLAIN SELECT pseudo,(SELECT email FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce')) FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce');
 -- error 1239
 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo,email FROM
 inscrit WHERE pseudo='joce');
@@ -97,3 +95,17 @@ SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo
 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo LIKE '%joce%');
 
 drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit;
+
+drop table if exists searchconthardwarefr3;
+CREATE TABLE `searchconthardwarefr3` (
+  `topic` mediumint(8) unsigned NOT NULL default '0',
+  `date` date NOT NULL default '0000-00-00',
+  `pseudo` varchar(35) character set latin1 NOT NULL default '',
+  PRIMARY KEY  (`pseudo`,`date`,`topic`),
+  KEY `topic` (`topic`)
+) TYPE=MyISAM ROW_FORMAT=DYNAMIC;
+INSERT INTO searchconthardwarefr3 (topic,date,pseudo) VALUES
+('43506','2002-10-02','joce'),('40143','2002-08-03','joce');
+EXPLAIN SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03';
+EXPLAIN SELECT (SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03');
+drop table searchconthardwarefr3;
\ No newline at end of file

sql/mysql_priv.h

@@ -392,6 +392,8 @@ int mysql_select(THD *thd,TABLE_LIST *tables,List<Item> &list,COND *conds,
 		 SELECT_LEX_UNIT *unit, SELECT_LEX *select_lex,
 		 bool fake_select_lex);
 void fix_tables_pointers(SELECT_LEX *select_lex);
+int mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit,
+			select_result *result);
 int mysql_explain_select(THD *thd, SELECT_LEX *sl, char const *type,
 			 select_result *result);
 int mysql_union(THD *thd, LEX *lex,select_result *result);

sql/sql_lex.cc

@@ -955,6 +955,7 @@ void st_select_lex::init_query()
   table_list.first= 0; 
   table_list.next= (byte**) &table_list.first;
   item_list.empty();
+  join= 0;
 }
 
 void st_select_lex::init_select()
@@ -973,7 +974,6 @@ void st_select_lex::init_select()
   ftfunc_list= &ftfunc_list_alloc;
   linkage= UNSPECIFIED_TYPE;
   depended= having_fix_field= 0;
-  
 }
 
 /*

sql/sql_parse.cc

@@ -1485,24 +1485,7 @@ mysql_execute_command(THD *thd)
 	  else
 	    thd->send_explain_fields(explain_result);
 	fix_tables_pointers(select_lex);
-	for ( SELECT_LEX *sl= select_lex;
-	     sl && res == 0;
-	     sl= sl->next_select_in_list())
-	{
-	  SELECT_LEX *first= sl->master_unit()->first_select();
-	  res= mysql_explain_select(thd, sl,
-				    ((select_lex==sl)?
-				     ((sl->next_select_in_list())?"PRIMARY":
-				       "SIMPLE"):
-				     ((sl == first)?
-				      ((sl->depended)?"DEPENDENT SUBSELECT":
-				       "SUBSELECT"):
-				      ((sl->depended)?"DEPENDENT UNION":
-				       "UNION"))),
-				    explain_result);
-	}
-	if (res > 0)
-	  res= -res; // mysql_explain_select do not report error
+	res= mysql_explain_union(thd, &thd->lex.unit, explain_result);
 	MYSQL_LOCK *save_lock= thd->lock;
 	thd->lock= (MYSQL_LOCK *)0;
 	explain_result->send_eof();

sql/sql_select.cc

@@ -1018,9 +1018,25 @@ mysql_select(THD *thd, TABLE_LIST *tables, List<Item> &fields, COND *conds,
 	     SELECT_LEX_UNIT *unit, SELECT_LEX *select_lex,
 	     bool fake_select_lex)
 {
-  JOIN *join = new JOIN(thd, fields, select_options, result);
-
   DBUG_ENTER("mysql_select");
+
+  bool free_join= 1;
+  JOIN *join;
+  if (!fake_select_lex && select_lex->join != 0)
+  {
+    //here is EXPLAIN of subselect or derived table
+    join= select_lex->join;
+    join->result= result;
+    if (!join->procedure && result->prepare(join->fields_list, unit))
+    {
+      DBUG_RETURN(-1);
+    }
+    join->select_options= select_options;
+    free_join= 0;
+  }
+  else
+  {
+    join= new JOIN(thd, fields, select_options, result);
     thd->proc_info="init";
     thd->used_tables=0;                         // Updated by setup_fields
 
@@ -1029,25 +1045,33 @@ mysql_select(THD *thd, TABLE_LIST *tables, List<Item> &fields, COND *conds,
     {
       DBUG_RETURN(-1);
     }
-  switch (join->optimize()) {
+  }
+
+  switch (join->optimize()) 
+  {
   case 1:
     DBUG_RETURN(join->error);
   case -1:
     goto err;
   } 
 
-  if (join->global_optimize())
+  if (free_join && join->global_optimize())
     goto err;
 
   join->exec();
 
 err:
+  if (free_join)
+  {
     thd->limit_found_rows = join->send_records;
     thd->examined_row_count = join->examined_rows;
     thd->proc_info="end";
     int error= (fake_select_lex?0:join->cleanup(thd)) || thd->net.report_error;
     delete join;
     DBUG_RETURN(error);
+  }
+  else
+    DBUG_RETURN(0);
 }
 
 /*****************************************************************************
@@ -7365,9 +7389,43 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
 	result->send_error(0,NullS);
     }
   }
+  for (SELECT_LEX_UNIT *unit= join->select_lex->first_inner_unit();
+       unit;
+       unit= unit->next_unit())
+  {
+    if (mysql_explain_union(thd, unit, result))
+      DBUG_VOID_RETURN;
+  }
   DBUG_VOID_RETURN;
 }
 
+int mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit, select_result *result)
+{
+  int res= 0;
+  SELECT_LEX *first= unit->first_select();
+  for (SELECT_LEX *sl= first;
+       sl;
+       sl= sl->next_select())
+  {
+    res= mysql_explain_select(thd, sl,
+			      (((&thd->lex.select_lex)==sl)?
+			       ((sl->next_select_in_list())?"PRIMARY":
+				"SIMPLE"):
+			       ((sl == first)?
+				((sl->depended)?"DEPENDENT SUBSELECT":
+				 "SUBSELECT"):
+				((sl->depended)?"DEPENDENT UNION":
+				 "UNION"))),
+			      result);
+    if (res)
+      break;
+
+  }
+  if (res > 0)
+    res= -res; // mysql_explain_select do not report error
+  return res;
+}
+
 int mysql_explain_select(THD *thd, SELECT_LEX *select_lex, char const *type, 
 			 select_result *result)
 {