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-rw-r--r--configure.in2
-rw-r--r--libmysqld/libmysqld.c2
-rw-r--r--mysql-test/r/func_group.result53
-rw-r--r--mysql-test/t/func_group.test27
-rw-r--r--sql/item.h1
-rw-r--r--sql/item_sum.h2
-rw-r--r--sql/opt_sum.cc92
-rw-r--r--sql/sql_select.cc6
8 files changed, 158 insertions, 27 deletions
diff --git a/configure.in b/configure.in
index 6e1e274fe3c..2255dd0e2b6 100644
--- a/configure.in
+++ b/configure.in
@@ -4,7 +4,7 @@ dnl Process this file with autoconf to produce a configure script.
AC_INIT(sql/mysqld.cc)
AC_CANONICAL_SYSTEM
# The Docs Makefile.am parses this line!
-AM_INIT_AUTOMAKE(mysql, 4.0.10-gamma)
+AM_INIT_AUTOMAKE(mysql, 4.0.11)
AM_CONFIG_HEADER(config.h)
PROTOCOL_VERSION=10
diff --git a/libmysqld/libmysqld.c b/libmysqld/libmysqld.c
index 3fba238a8bf..3f7c666cd30 100644
--- a/libmysqld/libmysqld.c
+++ b/libmysqld/libmysqld.c
@@ -62,7 +62,7 @@ my_string mysql_unix_port=0;
#define closesocket(A) close(A)
#endif
-static void mysql_once_init(void);
+void STDCALL mysql_once_init(void);
static MYSQL_DATA *read_rows (MYSQL *mysql,MYSQL_FIELD *fields,
uint field_count);
static int read_one_row(MYSQL *mysql,uint fields,MYSQL_ROW row,
diff --git a/mysql-test/r/func_group.result b/mysql-test/r/func_group.result
index c1f36283ab0..8263df36105 100644
--- a/mysql-test/r/func_group.result
+++ b/mysql-test/r/func_group.result
@@ -151,3 +151,56 @@ sum(num)
45.63
51.80
drop table t1;
+create table t1 (a1 int, a2 char(3), key k1(a1), key k2(a2));
+insert into t1 values(10,'aaa'), (10,null), (10,'bbb'), (20,'zzz');
+create table t2(a1 char(3), a2 int, a3 real, key k1(a1), key k2(a2, a1));
+select * from t1;
+a1 a2
+10 aaa
+10 NULL
+10 bbb
+20 zzz
+select min(a2) from t1;
+min(a2)
+aaa
+select max(t1.a1), max(t2.a2) from t1, t2;
+max(t1.a1) max(t2.a2)
+NULL NULL
+select max(t1.a1) from t1, t2;
+max(t1.a1)
+NULL
+select max(t2.a2), max(t1.a1) from t1, t2;
+max(t2.a2) max(t1.a1)
+NULL NULL
+explain select min(a2) from t1;
+Comment
+Select tables optimized away
+explain select max(t1.a1), max(t2.a2) from t1, t2;
+Comment
+No matching min/max row
+insert into t2 values('AAA', 10, 0.5);
+select max(t1.a1), max(t2.a1) from t1, t2 where t2.a2=9;
+max(t1.a1) max(t2.a1)
+NULL NULL
+select max(t2.a1), max(t1.a1) from t1, t2 where t2.a2=9;
+max(t2.a1) max(t1.a1)
+NULL NULL
+select t1.a1, t1.a2, t2.a1, t2.a2 from t1 left outer join t2 on t1.a1=10;
+a1 a2 a1 a2
+10 aaa AAA 10
+10 NULL AAA 10
+10 bbb AAA 10
+20 zzz NULL NULL
+select max(t1.a2) from t1 left outer join t2 on t1.a1=10;
+max(t1.a2)
+zzz
+select max(t1.a2) from t1 left outer join t2 on t1.a1=10 where t1.a1=20;
+max(t1.a2)
+zzz
+select max(t1.a2) from t1 left outer join t2 on t1.a1=10 where t1.a1=10;
+max(t1.a2)
+bbb
+select max(t2.a1) from t1 left outer join t2 on t1.a2=t2.a1 and 1=0 where t2.a1='AAA';
+max(t2.a1)
+NULL
+drop table t1,t2;
diff --git a/mysql-test/t/func_group.test b/mysql-test/t/func_group.test
index 57e9ae24e08..04a2ff68a92 100644
--- a/mysql-test/t/func_group.test
+++ b/mysql-test/t/func_group.test
@@ -99,3 +99,30 @@ insert into t1 values (5.2,'nem'),(8.64,'monty'),(11.12,'sinisa');
select sum(num) from t1;
select sum(num) from t1 group by user;
drop table t1;
+
+#
+# Test problem with MIN() optimization in case of null values
+#
+
+create table t1 (a1 int, a2 char(3), key k1(a1), key k2(a2));
+insert into t1 values(10,'aaa'), (10,null), (10,'bbb'), (20,'zzz');
+create table t2(a1 char(3), a2 int, a3 real, key k1(a1), key k2(a2, a1));
+select * from t1;
+# The following returned NULL in 4.0.10
+select min(a2) from t1;
+select max(t1.a1), max(t2.a2) from t1, t2;
+select max(t1.a1) from t1, t2;
+select max(t2.a2), max(t1.a1) from t1, t2;
+
+explain select min(a2) from t1;
+explain select max(t1.a1), max(t2.a2) from t1, t2;
+
+insert into t2 values('AAA', 10, 0.5);
+select max(t1.a1), max(t2.a1) from t1, t2 where t2.a2=9;
+select max(t2.a1), max(t1.a1) from t1, t2 where t2.a2=9;
+select t1.a1, t1.a2, t2.a1, t2.a2 from t1 left outer join t2 on t1.a1=10;
+select max(t1.a2) from t1 left outer join t2 on t1.a1=10;
+select max(t1.a2) from t1 left outer join t2 on t1.a1=10 where t1.a1=20;
+select max(t1.a2) from t1 left outer join t2 on t1.a1=10 where t1.a1=10;
+select max(t2.a1) from t1 left outer join t2 on t1.a2=t2.a1 and 1=0 where t2.a1='AAA';
+drop table t1,t2;
diff --git a/sql/item.h b/sql/item.h
index b690807691f..c669c266f0f 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -89,6 +89,7 @@ public:
virtual void set_result_field(Field *field) {}
virtual bool is_result_field() { return 0; }
virtual void save_in_result_field(bool no_conversions) {}
+ virtual void no_rows_in_result() {}
};
diff --git a/sql/item_sum.h b/sql/item_sum.h
index 2cf92343ebb..04f95dfd778 100644
--- a/sql/item_sum.h
+++ b/sql/item_sum.h
@@ -69,6 +69,7 @@ public:
void make_field(Send_field *field);
void print(String *str);
void fix_num_length_and_dec();
+ void no_rows_in_result() { reset(); }
virtual bool setup(THD *thd) {return 0;}
unsigned int size_of() { return sizeof(*this);}
};
@@ -135,6 +136,7 @@ class Item_sum_count :public Item_sum_int
bool const_item() const { return !used_table_cache; }
enum Sumfunctype sum_func () const { return COUNT_FUNC; }
void reset();
+ void no_rows_in_result() { count=0; }
bool add();
void make_const(longlong count_arg) { count=count_arg; used_table_cache=0; }
longlong val_int();
diff --git a/sql/opt_sum.cc b/sql/opt_sum.cc
index ecfa97586e9..d5a4149f243 100644
--- a/sql/opt_sum.cc
+++ b/sql/opt_sum.cc
@@ -1,4 +1,4 @@
-/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
+/* Copyright (C) 2000-2003 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -22,28 +22,55 @@
static bool find_range_key(TABLE_REF *ref, Field* field,COND *cond);
-/*****************************************************************************
-** This function is only called for queries with sum functions and no
-** GROUP BY part.
-** This substitutes constants for some COUNT(), MIN() and MAX() functions.
-** The function returns 1 if all items was resolved and -1 on impossible
-** conditions
-****************************************************************************/
+/*
+ Substitutes constants for some COUNT(), MIN() and MAX() functions.
+
+ SYNOPSIS
+ opt_sum_query()
+ tables Tables in query
+ all_fields All fields to be returned
+ conds WHERE clause
+
+ NOTE:
+ This function is only called for queries with sum functions and no
+ GROUP BY part.
+
+ RETURN VALUES
+ 0 No errors
+ 1 if all items was resolved
+ -1 on impossible conditions
+*/
int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
{
List_iterator_fast<Item> it(all_fields);
- int const_result=1;
- bool recalc_const_item=0;
- table_map removed_tables=0;
+ int const_result= 1;
+ bool recalc_const_item= 0;
+ table_map removed_tables= 0, outer_tables= 0, used_tables= 0;
+ table_map where_tables= 0;
Item *item;
COND *org_conds= conds;
- /* Add all ON conditions to WHERE condition */
+ if (conds)
+ where_tables= conds->used_tables();
+
+ /* Don't replace expression on a table that is part of an outer join */
for (TABLE_LIST *tl=tables; tl ; tl= tl->next)
{
if (tl->on_expr)
- conds= and_expressions(conds, tl->on_expr, &org_conds);
+ {
+ outer_tables|= tl->table->map;
+
+ /*
+ We can't optimise LEFT JOIN in cases where the WHERE condition
+ restricts the table that is used, like in:
+ SELECT MAX(t1.a) FROM t1 LEFT JOIN t2 join-condition
+ WHERE t2.field IS NULL;
+ */
+ if (tl->table->map & where_tables)
+ return 0;
+ }
+ used_tables|= tl->table->map;
}
/*
@@ -68,8 +95,8 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
TABLE_LIST *table;
for (table=tables; table ; table=table->next)
{
- if (table->on_expr || (table->table->file->table_flags() &
- HA_NOT_EXACT_COUNT))
+ if (outer_tables || (table->table->file->table_flags() &
+ HA_NOT_EXACT_COUNT))
{
const_result=0; // Can't optimize left join
break;
@@ -99,21 +126,35 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
byte key_buff[MAX_KEY_LENGTH];
TABLE_REF ref;
ref.key_buff=key_buff;
+ Item_field *item_field= ((Item_field*) expr);
+ TABLE *table= item_field->field->table;
- if (!find_range_key(&ref, ((Item_field*) expr)->field,conds))
+ if ((outer_tables & table->map) ||
+ (!find_range_key(&ref, item_field->field,conds)))
{
const_result=0;
break;
}
- TABLE *table=((Item_field*) expr)->field->table;
- bool error=table->file->index_init((uint) ref.key);
+ bool error= table->file->index_init((uint) ref.key);
+ enum ha_rkey_function find_flag= HA_READ_KEY_OR_NEXT;
+ uint prefix_len= ref.key_length;
+ /*
+ If we are doing MIN() on a column with NULL fields
+ we must read the key after the NULL column
+ */
+ if (item_field->field->null_bit)
+ {
+ ref.key_buff[ref.key_length++]=1;
+ find_flag= HA_READ_AFTER_KEY;
+ }
+
if (!ref.key_length)
error=table->file->index_first(table->record[0]) !=0;
else
error=table->file->index_read(table->record[0],key_buff,
ref.key_length,
- HA_READ_KEY_OR_NEXT) ||
- key_cmp(table, key_buff, ref.key, ref.key_length);
+ find_flag) ||
+ key_cmp(table, key_buff, ref.key, prefix_len);
if (table->key_read)
{
table->key_read=0;
@@ -121,7 +162,7 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
}
table->file->index_end();
if (error)
- return -1; // Impossible query
+ return -1; // No rows matching where
removed_tables|= table->map;
}
else if (!expr->const_item()) // This is VERY seldom false
@@ -147,13 +188,14 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
byte key_buff[MAX_KEY_LENGTH];
TABLE_REF ref;
ref.key_buff=key_buff;
+ TABLE *table=((Item_field*) expr)->field->table;
- if (!find_range_key(&ref, ((Item_field*) expr)->field,conds))
+ if ((outer_tables & table->map) ||
+ !find_range_key(&ref, ((Item_field*) expr)->field,conds))
{
const_result=0;
break;
}
- TABLE *table=((Item_field*) expr)->field->table;
if ((table->file->table_flags() & HA_NOT_READ_AFTER_KEY))
{
const_result=0;
@@ -203,8 +245,8 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
const_result=0;
}
}
- if (conds && (conds->used_tables() & ~ removed_tables))
- const_result=0;
+ if (used_tables != removed_tables)
+ const_result=0; // We didn't remove all tables
return const_result;
}
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 6996bba8798..be5e5be7cb7 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -3104,7 +3104,13 @@ return_zero_rows(JOIN *join, select_result *result,TABLE_LIST *tables,
if (!(result->send_fields(fields,1)))
{
if (send_row)
+ {
+ List_iterator_fast<Item> it(fields);
+ Item *item;
+ while ((item= it++))
+ item->no_rows_in_result();
result->send_data(fields);
+ }
if (tables) // Not from do_select()
{
/* Close open cursors */
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