Return character strings in table, type, possible_keys, key fields

of EXPLAIN SELECT, rather than binary strings.

mysql-test/r/ps_1general.result

@@ -414,15 +414,15 @@ prepare stmt1 from ' explain select a from t1 order by b ';
 execute stmt1;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	6	N	1	31	63
-def					table	253	64	2	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	6	N	1	31	8
+def					table	253	64	2	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	14	N	1	31	63
+def					Extra	253	255	14	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	Using filesort
 SET @arg00=1 ;
@@ -430,15 +430,15 @@ prepare stmt1 from ' explain select a from t1 where a > ? order by b ';
 execute stmt1 using @arg00;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	6	N	1	31	63
-def					table	253	64	2	N	1	31	63
-def					type	253	10	5	N	1	31	63
-def					possible_keys	253	4096	7	Y	0	31	63
-def					key	253	64	7	Y	0	31	63
+def					select_type	253	19	6	N	1	31	8
+def					table	253	64	2	N	1	31	8
+def					type	253	10	5	N	1	31	8
+def					possible_keys	253	4096	7	Y	0	31	8
+def					key	253	64	7	Y	0	31	8
 def					key_len	8	3	1	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	27	N	1	31	63
+def					Extra	253	255	27	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	PRIMARY	PRIMARY	4	NULL	3	Using where; Using filesort
 test_sequence

mysql-test/r/ps_2myisam.result

@@ -574,15 +574,15 @@ prepare stmt1 from @stmt ;
 execute stmt1 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where
@@ -645,15 +645,15 @@ execute stmt1 using @arg00, @arg01, @arg02, @arg03, @arg04, @arg05, @arg06,
 @arg07, @arg08, @arg09 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where

mysql-test/r/ps_3innodb.result

@@ -574,15 +574,15 @@ prepare stmt1 from @stmt ;
 execute stmt1 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where
@@ -645,15 +645,15 @@ execute stmt1 using @arg00, @arg01, @arg02, @arg03, @arg04, @arg05, @arg06,
 @arg07, @arg08, @arg09 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where

mysql-test/r/ps_4heap.result

@@ -575,15 +575,15 @@ prepare stmt1 from @stmt ;
 execute stmt1 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where
@@ -646,15 +646,15 @@ execute stmt1 using @arg00, @arg01, @arg02, @arg03, @arg04, @arg05, @arg06,
 @arg07, @arg08, @arg09 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where

mysql-test/r/ps_5merge.result

@@ -617,15 +617,15 @@ prepare stmt1 from @stmt ;
 execute stmt1 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where
@@ -688,15 +688,15 @@ execute stmt1 using @arg00, @arg01, @arg02, @arg03, @arg04, @arg05, @arg06,
 @arg07, @arg08, @arg09 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where
@@ -1812,15 +1812,15 @@ prepare stmt1 from @stmt ;
 execute stmt1 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where
@@ -1883,15 +1883,15 @@ execute stmt1 using @arg00, @arg01, @arg02, @arg03, @arg04, @arg05, @arg06,
 @arg07, @arg08, @arg09 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where

mysql-test/r/ps_6bdb.result

@@ -574,15 +574,15 @@ prepare stmt1 from @stmt ;
 execute stmt1 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where
@@ -645,15 +645,15 @@ execute stmt1 using @arg00, @arg01, @arg02, @arg03, @arg04, @arg05, @arg06,
 @arg07, @arg08, @arg09 ;
 Catalog	Database	Table	Table_alias	Column	Column_alias	Name	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
 def					id	8	3	1	N	32801	0	8
-def					select_type	253	19	18	N	1	31	63
-def					table	253	64	16	N	1	31	63
-def					type	253	10	3	N	1	31	63
-def					possible_keys	253	4096	0	Y	0	31	63
-def					key	253	64	0	Y	0	31	63
+def					select_type	253	19	18	N	1	31	8
+def					table	253	64	16	N	1	31	8
+def					type	253	10	3	N	1	31	8
+def					possible_keys	253	4096	0	Y	0	31	8
+def					key	253	64	0	Y	0	31	8
 def					key_len	8	3	0	Y	32800	0	8
-def					ref	253	1024	0	Y	0	31	63
+def					ref	253	1024	0	Y	0	31	8
 def					rows	8	10	1	N	32801	0	8
-def					Extra	253	255	44	N	1	31	63
+def					Extra	253	255	44	N	1	31	8
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t_many_col_types	ALL	NULL	NULL	NULL	NULL	2	
 1	PRIMARY	<derived6>	ALL	NULL	NULL	NULL	NULL	2	Using where

sql/item.h

@@ -706,8 +706,8 @@ class Item_datetime :public Item_string
 class Item_empty_string :public Item_string
 {
 public:
-  Item_empty_string(const char *header,uint length) :Item_string("",0,
-  							&my_charset_bin)
+  Item_empty_string(const char *header,uint length, CHARSET_INFO *cs= NULL) :
+    Item_string("",0, cs ? cs : &my_charset_bin)
     { name=(char*) header; max_length=length;}
   void make_field(Send_field *field);
 };

sql/sql_class.cc

@@ -654,27 +654,29 @@ CHANGED_TABLE_LIST* THD::changed_table_dup(const char *key, long key_length)
   return new_table;
 }
 
+
 int THD::send_explain_fields(select_result *result)
 {
   List<Item> field_list;
   Item *item;
+  CHARSET_INFO *cs= system_charset_info;
   field_list.push_back(new Item_return_int("id",3, MYSQL_TYPE_LONGLONG));
-  field_list.push_back(new Item_empty_string("select_type",19));
-  field_list.push_back(new Item_empty_string("table",NAME_LEN));
-  field_list.push_back(new Item_empty_string("type",10));
+  field_list.push_back(new Item_empty_string("select_type", 19, cs));
+  field_list.push_back(new Item_empty_string("table", NAME_LEN, cs));
+  field_list.push_back(new Item_empty_string("type", 10, cs));
   field_list.push_back(item=new Item_empty_string("possible_keys",
-						  NAME_LEN*MAX_KEY));
+						  NAME_LEN*MAX_KEY, cs));
   item->maybe_null=1;
-  field_list.push_back(item=new Item_empty_string("key",NAME_LEN));
+  field_list.push_back(item=new Item_empty_string("key", NAME_LEN, cs));
   item->maybe_null=1;
   field_list.push_back(item=new Item_return_int("key_len",3,
 						MYSQL_TYPE_LONGLONG));
   item->maybe_null=1;
   field_list.push_back(item=new Item_empty_string("ref",
-						  NAME_LEN*MAX_REF_PARTS));
+						  NAME_LEN*MAX_REF_PARTS, cs));
   item->maybe_null=1;
-  field_list.push_back(new Item_return_int("rows",10, MYSQL_TYPE_LONGLONG));
-  field_list.push_back(new Item_empty_string("Extra",255));
+  field_list.push_back(new Item_return_int("rows", 10, MYSQL_TYPE_LONGLONG));
+  field_list.push_back(new Item_empty_string("Extra", 255, cs));
   return (result->send_fields(field_list,1));
 }