Skip to content

M
mariadb
Commit ed418461 authored by Tor Didriksen's avatar Tor Didriksen
Browse files
Options

Patch for Bug#13805127: Stored program cache produces wrong result in same THD. 

Background:

  - as described in MySQL Internals Prepared Stored
    (http://forge.mysql.com/wiki/MySQL_Internals_Prepared_Stored),
    the Optimizer sometimes does destructive changes to the parsed
    LEX-object (Item-tree), which makes it impossible to re-use
    that tree for PS/SP re-execution.

  - in order to be able to re-use the Item-tree, the destructive
    changes are remembered and rolled back after the statement execution.

The problem, discovered by this bug, was that the objects representing
GROUP-BY clause did not restored after query execution. So, the GROUP-BY
part of the statement could not be properly re-initialized for re-execution
after destructive changes.

Those objects do not take part in the Item-tree, so they can not be saved
using the approach for Item-tree.

The fix is as follows:

  - introduce a new array in st_select_lex to store the original
    ORDER pointers, representing the GROUP-BY clause;

  - Initialize this array in fix_prepare_information().

  - restore the list of GROUP-BY items in reinit_stmt_before_use().
parent d1809a5c
Hide whitespace changes
Inline Side-by-side
Showing with 485 additions and 2 deletions
mysql-test/r/ps.result
View file @ ed418461
......@@ -3746,5 +3746,108 @@ FROM (SELECT 1 UNION SELECT 2) t;
1
1
2
# Bug#13805127: Stored program cache produces wrong result in same THD
PREPARE s1 FROM
"
SELECT c1, t2.c2, count(c3)
FROM
(
SELECT 3 as c2 FROM dual WHERE @x = 1
UNION
SELECT 2 FROM dual WHERE @x = 1 OR @x = 2
) AS t1,
(
SELECT '2012-03-01 01:00:00' AS c1, 3 as c2, 1 as c3 FROM dual
UNION
SELECT '2012-03-01 02:00:00', 3, 2 FROM dual
UNION
SELECT '2012-03-01 01:00:00', 2, 1 FROM dual
) AS t2
WHERE t2.c2 = t1.c2
GROUP BY c1, c2
";
SET @x = 1;
SELECT c1, t2.c2, count(c3)
FROM
(
SELECT 3 as c2 FROM dual WHERE @x = 1
UNION
SELECT 2 FROM dual WHERE @x = 1 OR @x = 2
) AS t1,
(
SELECT '2012-03-01 01:00:00' AS c1, 3 as c2, 1 as c3 FROM dual
UNION
SELECT '2012-03-01 02:00:00', 3, 2 FROM dual
UNION
SELECT '2012-03-01 01:00:00', 2, 1 FROM dual
) AS t2
WHERE t2.c2 = t1.c2
GROUP BY c1, c2;
c1 c2 count(c3)
2012-03-01 01:00:00 2 1
2012-03-01 01:00:00 3 1
2012-03-01 02:00:00 3 1
EXECUTE s1;
c1 c2 count(c3)
2012-03-01 01:00:00 2 1
2012-03-01 01:00:00 3 1
2012-03-01 02:00:00 3 1
SET @x = 2;
SELECT c1, t2.c2, count(c3)
FROM
(
SELECT 3 as c2 FROM dual WHERE @x = 1
UNION
SELECT 2 FROM dual WHERE @x = 1 OR @x = 2
) AS t1,
(
SELECT '2012-03-01 01:00:00' AS c1, 3 as c2, 1 as c3 FROM dual
UNION
SELECT '2012-03-01 02:00:00', 3, 2 FROM dual
UNION
SELECT '2012-03-01 01:00:00', 2, 1 FROM dual
) AS t2
WHERE t2.c2 = t1.c2
GROUP BY c1, c2;
c1 c2 count(c3)
2012-03-01 01:00:00 2 1
EXECUTE s1;
c1 c2 count(c3)
2012-03-01 01:00:00 2 1
SET @x = 1;
SELECT c1, t2.c2, count(c3)
FROM
(
SELECT 3 as c2 FROM dual WHERE @x = 1
UNION
SELECT 2 FROM dual WHERE @x = 1 OR @x = 2
) AS t1,
(
SELECT '2012-03-01 01:00:00' AS c1, 3 as c2, 1 as c3 FROM dual
UNION
SELECT '2012-03-01 02:00:00', 3, 2 FROM dual
UNION
SELECT '2012-03-01 01:00:00', 2, 1 FROM dual
) AS t2
WHERE t2.c2 = t1.c2
GROUP BY c1, c2;
c1 c2 count(c3)
2012-03-01 01:00:00 2 1
2012-03-01 01:00:00 3 1
2012-03-01 02:00:00 3 1
EXECUTE s1;
c1 c2 count(c3)
2012-03-01 01:00:00 2 1
2012-03-01 01:00:00 3 1
2012-03-01 02:00:00 3 1
DEALLOCATE PREPARE s1;
#
# End of 5.5 tests.
mysql-test/r/sp.result
View file @ ed418461
......@@ -7747,6 +7747,44 @@ CALL p2();
DROP PROCEDURE p1;
DROP PROCEDURE p2;
DROP TABLE t1;
# Bug#13805127: Stored program cache produces wrong result in same THD
CREATE PROCEDURE p1(x INT UNSIGNED)
BEGIN
SELECT c1, t2.c2, count(c3)
FROM
(
SELECT 3 as c2 FROM dual WHERE x = 1
UNION
SELECT 2 FROM dual WHERE x = 1 OR x = 2
) AS t1,
(
SELECT '2012-03-01 01:00:00' AS c1, 3 as c2, 1 as c3 FROM dual
UNION
SELECT '2012-03-01 02:00:00', 3, 2 FROM dual
UNION
SELECT '2012-03-01 01:00:00', 2, 1 FROM dual
) AS t2
WHERE t2.c2 = t1.c2
GROUP BY c1, c2
;
END|
CALL p1(1);
c1 c2 count(c3)
2012-03-01 01:00:00 2 1
2012-03-01 01:00:00 3 1
2012-03-01 02:00:00 3 1
CALL p1(2);
c1 c2 count(c3)
2012-03-01 01:00:00 2 1
CALL p1(1);
c1 c2 count(c3)
2012-03-01 01:00:00 2 1
2012-03-01 01:00:00 3 1
2012-03-01 02:00:00 3 1
DROP PROCEDURE p1;
# End of 5.5 test
#
# Bug#12663165 SP DEAD CODE REMOVAL DOESN'T UNDERSTAND CONTINUE HANDLERS
......
mysql-test/t/ps.test
View file @ ed418461
......@@ -3364,6 +3364,94 @@ disconnect con1;
SELECT *
FROM (SELECT 1 UNION SELECT 2) t;
--echo
--echo # Bug#13805127: Stored program cache produces wrong result in same THD
--echo
PREPARE s1 FROM
"
SELECT c1, t2.c2, count(c3)
FROM
(
SELECT 3 as c2 FROM dual WHERE @x = 1
UNION
SELECT 2 FROM dual WHERE @x = 1 OR @x = 2
) AS t1,
(
SELECT '2012-03-01 01:00:00' AS c1, 3 as c2, 1 as c3 FROM dual
UNION
SELECT '2012-03-01 02:00:00', 3, 2 FROM dual
UNION
SELECT '2012-03-01 01:00:00', 2, 1 FROM dual
) AS t2
WHERE t2.c2 = t1.c2
GROUP BY c1, c2
";
--echo
SET @x = 1;
SELECT c1, t2.c2, count(c3)
FROM
(
SELECT 3 as c2 FROM dual WHERE @x = 1
UNION
SELECT 2 FROM dual WHERE @x = 1 OR @x = 2
) AS t1,
(
SELECT '2012-03-01 01:00:00' AS c1, 3 as c2, 1 as c3 FROM dual
UNION
SELECT '2012-03-01 02:00:00', 3, 2 FROM dual
UNION
SELECT '2012-03-01 01:00:00', 2, 1 FROM dual
) AS t2
WHERE t2.c2 = t1.c2
GROUP BY c1, c2;
--echo
EXECUTE s1;
--echo
SET @x = 2;
SELECT c1, t2.c2, count(c3)
FROM
(
SELECT 3 as c2 FROM dual WHERE @x = 1
UNION
SELECT 2 FROM dual WHERE @x = 1 OR @x = 2
) AS t1,
(
SELECT '2012-03-01 01:00:00' AS c1, 3 as c2, 1 as c3 FROM dual
UNION
SELECT '2012-03-01 02:00:00', 3, 2 FROM dual
UNION
SELECT '2012-03-01 01:00:00', 2, 1 FROM dual
) AS t2
WHERE t2.c2 = t1.c2
GROUP BY c1, c2;
--echo
EXECUTE s1;
--echo
SET @x = 1;
SELECT c1, t2.c2, count(c3)
FROM
(
SELECT 3 as c2 FROM dual WHERE @x = 1
UNION
SELECT 2 FROM dual WHERE @x = 1 OR @x = 2
) AS t1,
(
SELECT '2012-03-01 01:00:00' AS c1, 3 as c2, 1 as c3 FROM dual
UNION
SELECT '2012-03-01 02:00:00', 3, 2 FROM dual
UNION
SELECT '2012-03-01 01:00:00', 2, 1 FROM dual
) AS t2
WHERE t2.c2 = t1.c2
GROUP BY c1, c2;
--echo
EXECUTE s1;
DEALLOCATE PREPARE s1;
--echo #
--echo # End of 5.5 tests.
......
mysql-test/t/sp.test
View file @ ed418461
......@@ -9027,6 +9027,42 @@ DROP PROCEDURE p1;
DROP PROCEDURE p2;
DROP TABLE t1;
--echo
--echo # Bug#13805127: Stored program cache produces wrong result in same THD
--echo
delimiter |;
CREATE PROCEDURE p1(x INT UNSIGNED)
BEGIN
SELECT c1, t2.c2, count(c3)
FROM
(
SELECT 3 as c2 FROM dual WHERE x = 1
UNION
SELECT 2 FROM dual WHERE x = 1 OR x = 2
) AS t1,
(
SELECT '2012-03-01 01:00:00' AS c1, 3 as c2, 1 as c3 FROM dual
UNION
SELECT '2012-03-01 02:00:00', 3, 2 FROM dual
UNION
SELECT '2012-03-01 01:00:00', 2, 1 FROM dual
) AS t2
WHERE t2.c2 = t1.c2
GROUP BY c1, c2
;
END|
delimiter ;|
--echo
CALL p1(1);
CALL p1(2);
CALL p1(1);
DROP PROCEDURE p1;
--echo # End of 5.5 test
......
sql/mem_root_array.h 0 → 100644
View file @ ed418461
/* Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
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
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifndef MEM_ROOT_ARRAY_INCLUDED
#define MEM_ROOT_ARRAY_INCLUDED
#include <my_alloc.h>
/**
A typesafe replacement for DYNAMIC_ARRAY.
We use MEM_ROOT for allocating storage, rather than the C++ heap.
The interface is chosen to be similar to std::vector.
@remark
Unlike DYNAMIC_ARRAY, elements are properly copied
(rather than memcpy()d) if the underlying array needs to be expanded.
@remark
Depending on has_trivial_destructor, we destroy objects which are
removed from the array (including when the array object itself is destroyed).
@remark
Note that MEM_ROOT has no facility for reusing free space,
so don't use this if multiple re-expansions are likely to happen.
@param Element_type The type of the elements of the container.
Elements must be copyable.
@param has_trivial_destructor If true, we don't destroy elements.
We could have used type traits to determine this.
__has_trivial_destructor is supported by some (but not all)
compilers we use.
*/
template<typename Element_type, bool has_trivial_destructor>
class Mem_root_array
{
public:
Mem_root_array(MEM_ROOT *root)
: m_root(root), m_array(NULL), m_size(0), m_capacity(0)
{
DBUG_ASSERT(m_root != NULL);
}
~Mem_root_array()
{
clear();
}
Element_type &at(size_t n)
{
DBUG_ASSERT(n < size());
return m_array[n];
}
const Element_type &at(size_t n) const
{
DBUG_ASSERT(n < size());
return m_array[n];
}
// Returns a pointer to the first element in the array.
Element_type *begin() { return &m_array[0]; }
// Returns a pointer to the past-the-end element in the array.
Element_type *end() { return &m_array[size()]; }
// Erases all of the elements.
void clear()
{
if (!empty())
chop(0);
}
/*
Chops the tail off the array, erasing all tail elements.
@param pos Index of first element to erase.
*/
void chop(const size_t pos)
{
DBUG_ASSERT(pos < m_size);
if (!has_trivial_destructor)
{
for (size_t ix= pos; ix < m_size; ++ix)
{
Element_type *p= &m_array[ix];
p->~Element_type(); // Destroy discarded element.
}
}
m_size= pos;
}
/*
Reserves space for array elements.
Copies over existing elements, in case we are re-expanding the array.
@param n number of elements.
@retval true if out-of-memory, false otherwise.
*/
bool reserve(size_t n)
{
if (n <= m_capacity)
return false;
void *mem= alloc_root(m_root, n * element_size());
if (!mem)
return true;
Element_type *array= static_cast<Element_type*>(mem);
// Copy all the existing elements into the new array.
for (size_t ix= 0; ix < m_size; ++ix)
{
Element_type *new_p= &array[ix];
Element_type *old_p= &m_array[ix];
new (new_p) Element_type(*old_p); // Copy into new location.
if (!has_trivial_destructor)
old_p->~Element_type(); // Destroy the old element.
}
// Forget the old array.
m_array= array;
m_capacity= n;
return false;
}
/*
Adds a new element at the end of the array, after its current last
element. The content of this new element is initialized to a copy of
the input argument.
@param element Object to copy.
@retval true if out-of-memory, false otherwise.
*/
bool push_back(const Element_type &element)
{
const size_t min_capacity= 20;
const size_t expansion_factor= 2;
if (0 == m_capacity && reserve(min_capacity))
return true;
if (m_size == m_capacity && reserve(m_capacity * expansion_factor))
return true;
Element_type *p= &m_array[m_size++];
new (p) Element_type(element);
return false;
}
size_t capacity() const { return m_capacity; }
size_t element_size() const { return sizeof(Element_type); }
bool empty() const { return size() == 0; }
size_t size() const { return m_size; }
private:
MEM_ROOT *const m_root;
Element_type *m_array;
size_t m_size;
size_t m_capacity;
// Not (yet) implemented.
Mem_root_array(const Mem_root_array&);
Mem_root_array &operator=(const Mem_root_array&);
};
#endif // MEM_ROOT_ARRAY_INCLUDED
sql/sql_lex.cc
View file @ ed418461
......@@ -389,6 +389,8 @@ void lex_start(THD *thd)
lex->select_lex.sql_cache= SELECT_LEX::SQL_CACHE_UNSPECIFIED;
lex->select_lex.init_order();
lex->select_lex.group_list.empty();
if (lex->select_lex.group_list_ptrs)
lex->select_lex.group_list_ptrs->clear();
lex->describe= 0;
lex->subqueries= FALSE;
lex->context_analysis_only= 0;
......@@ -1773,6 +1775,8 @@ void st_select_lex::init_select()
{
st_select_lex_node::init_select();
group_list.empty();
if (group_list_ptrs)
group_list_ptrs->clear();
type= db= 0;
having= 0;
table_join_options= 0;
......@@ -3100,6 +3104,8 @@ static void fix_prepare_info_in_table_list(THD *thd, TABLE_LIST *tbl)
The passed WHERE and HAVING are to be saved for the future executions.
This function saves it, and returns a copy which can be thrashed during
this execution of the statement. By saving/thrashing here we mean only
We also save the chain of ORDER::next in group_list, in case
the list is modified by remove_const().
AND/OR trees.
The function also calls fix_prepare_info_in_table_list that saves all
ON expressions.
......@@ -3111,6 +3117,19 @@ void st_select_lex::fix_prepare_information(THD *thd, Item **conds,
if (!thd->stmt_arena->is_conventional() && first_execution)
{
first_execution= 0;
if (group_list.first)
{
if (!group_list_ptrs)
{
void *mem= thd->stmt_arena->alloc(sizeof(Group_list_ptrs));
group_list_ptrs= new (mem) Group_list_ptrs(thd->stmt_arena->mem_root);
}
group_list_ptrs->reserve(group_list.elements);
for (ORDER *order= group_list.first; order; order= order->next)
{
group_list_ptrs->push_back(order);
}
}
if (*conds)
{
prep_where= *conds;
......@@ -3362,3 +3381,7 @@ void binlog_unsafe_map_init()
BINLOG_DIRECT_OFF & TRX_CACHE_NOT_EMPTY);
}
#endif
#ifdef HAVE_EXPLICIT_TEMPLATE_INSTANTIATION
template class Mem_root_array<ORDER*, true>;
#endif
sql/sql_lex.h
View file @ ed418461
......@@ -24,6 +24,7 @@
#include "sql_trigger.h"
#include "item.h" /* From item_subselect.h: subselect_union_engine */
#include "thr_lock.h" /* thr_lock_type, TL_UNLOCK */
#include "mem_root_array.h"
/* YACC and LEX Definitions */
......@@ -258,6 +259,7 @@ enum enum_drop_mode
#define TL_OPTION_ALIAS 8
typedef List<Item> List_item;
typedef Mem_root_array<ORDER*, true> Group_list_ptrs;
/* SERVERS CACHE CHANGES */
typedef struct st_lex_server_options
......@@ -693,7 +695,16 @@ public:
enum olap_type olap;
/* FROM clause - points to the beginning of the TABLE_LIST::next_local list. */
SQL_I_List<TABLE_LIST> table_list;
SQL_I_List<ORDER> group_list; /* GROUP BY clause. */
/*
GROUP BY clause.
This list may be mutated during optimization (by remove_const()),
so for prepared statements, we keep a copy of the ORDER.next pointers in
group_list_ptrs, and re-establish the original list before each execution.
*/
SQL_I_List<ORDER> group_list;
Group_list_ptrs *group_list_ptrs;
List<Item> item_list; /* list of fields & expressions */
List<String> interval_list;
bool is_item_list_lookup;
......@@ -870,7 +881,8 @@ public:
bool test_limit();
friend void lex_start(THD *thd);
st_select_lex() : n_sum_items(0), n_child_sum_items(0) {}
st_select_lex() : group_list_ptrs(NULL), n_sum_items(0), n_child_sum_items(0)
{}
void make_empty_select()
{
init_query();
......
sql/sql_prepare.cc
View file @ ed418461
......@@ -2422,6 +2422,14 @@ void reinit_stmt_before_use(THD *thd, LEX *lex)
DBUG_ASSERT(sl->join == 0);
ORDER *order;
/* Fix GROUP list */
if (sl->group_list_ptrs && sl->group_list_ptrs->size() > 0)
{
for (uint ix= 0; ix < sl->group_list_ptrs->size() - 1; ++ix)
{
order= sl->group_list_ptrs->at(ix);
order->next= sl->group_list_ptrs->at(ix+1);
}
}
for (order= sl->group_list.first; order; order= order->next)
order->item= &order->item_ptr;
/* Fix ORDER list */
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7