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BUG#834534: Assertion `0' failed in replace_where_subcondition with semijoin subquery in HAVING

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- The problem was that the code that made the check whether the subquery is an AND-part of the WHERE 
  clause didn't work correctly for nested subqueries. In particular, grand-child subquery in HAVING was 
  treated as if it was in the WHERE, which eventually caused an assert when replace_where_subcondition
  looked for the subquery predicate in the WHERE and couldn't find it there.

- The fix: Removed implementation of "thd_marker approach". thd->thd_marker was used to determine the 
  location of subquery predicate: setup_conds() would set accordingly it when making the 

    {where|on_expr}->fix_fields(...)

  call so that AND-parts of the WHERE/ON clauses can determine they are the AND-parts. 
  Item_cond_or::fix_fields(), Item_func::fix_fields(), Item_subselect::fix_fields (this one was missed),
  and all other items-that-contain-items had to reset thd->thd_marker before calling fix_fields() for 
  their children items, so that the children can see they are not AND-parts of WHERE/ON.
- The "thd_marker approach" required that a lot of code in different locations maintains correct value of
  thd->thd_marker, so it was replaced with:
- The new approach with mark_as_condition_AND_part does not keep context in thd->thd_marker. Instead, 
  setup_conds() now calls

    {where|on_expr}->mark_as_condition_AND_part()

  and implementations of that function make sure that: 
   - parts of AND-expressions get the mark_as_condition_AND_part() call
   - Item_in_subselect objects record that they are AND-parts of WHERE/ON
This commit is contained in:
Sergey Petrunya
2011-08-29 19:57:41 +04:00
parent 2df1914791
commit 945a595aa3
14 changed files with 96 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
mysql-test/r/subselect_sj.result
View File

@ -1729,4 +1729,24 @@ c1 c2
2 7
5 6
DROP TABLE t1, t2, t3;
#
# BUG#834534: Assertion `0' failed in replace_where_subcondition with semijoin subquery in HAVING
#
CREATE TABLE t1 ( d int );
INSERT INTO t1 VALUES (2),(2),(0),(2),(2);
CREATE TABLE t2 ( b int );
INSERT INTO t2 VALUES (4),(3),(3);
CREATE TABLE t3 ( a int );
SELECT *
FROM t3
WHERE (t3.a) IN (
SELECT t1.d
FROM t1
HAVING ( 4 ) IN (
SELECT t2.b
FROM t2
)
);
a
drop table t1, t2,t3;
set optimizer_switch=@subselect_sj_tmp;

20
mysql-test/r/subselect_sj_jcl6.result
View File

@ -1740,6 +1740,26 @@ c1 c2
2 7
5 6
DROP TABLE t1, t2, t3;
#
# BUG#834534: Assertion `0' failed in replace_where_subcondition with semijoin subquery in HAVING
#
CREATE TABLE t1 ( d int );
INSERT INTO t1 VALUES (2),(2),(0),(2),(2);
CREATE TABLE t2 ( b int );
INSERT INTO t2 VALUES (4),(3),(3);
CREATE TABLE t3 ( a int );
SELECT *
FROM t3
WHERE (t3.a) IN (
SELECT t1.d
FROM t1
HAVING ( 4 ) IN (
SELECT t2.b
FROM t2
)
);
a
drop table t1, t2,t3;
set optimizer_switch=@subselect_sj_tmp;
#
# BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off

23
mysql-test/t/subselect_sj.test
View File

@ -1571,5 +1571,28 @@ SELECT * FROM t1 WHERE c1 IN ( SELECT t3.c1 FROM t3 LEFT JOIN t2 ON t2 .c1 = t3
DROP TABLE t1, t2, t3;
--echo #
--echo # BUG#834534: Assertion `0' failed in replace_where_subcondition with semijoin subquery in HAVING
--echo #
CREATE TABLE t1 ( d int );
INSERT INTO t1 VALUES (2),(2),(0),(2),(2);
CREATE TABLE t2 ( b int );
INSERT INTO t2 VALUES (4),(3),(3);
CREATE TABLE t3 ( a int );
SELECT *
FROM t3
WHERE (t3.a) IN (
SELECT t1.d
FROM t1
HAVING ( 4 ) IN (
SELECT t2.b
FROM t2
)
);
drop table t1, t2,t3;
# The following command must be the last one the file
set optimizer_switch=@subselect_sj_tmp;

2
sql/item.h
View File

@ -1292,6 +1292,8 @@ public:
be defined for Item_func.
*/
virtual void get_cache_parameters(List<Item> &parameters) { };
virtual void mark_as_condition_AND_part(TABLE_LIST *embedding) {};
};

15
sql/item_cmpfunc.cc
View File

@ -4076,15 +4076,12 @@ Item_cond::fix_fields(THD *thd, Item **ref)
DBUG_ASSERT(fixed == 0);
List_iterator<Item> li(list);
Item *item;
TABLE_LIST *save_emb_on_expr_nest= thd->thd_marker.emb_on_expr_nest;
#ifndef EMBEDDED_LIBRARY
uchar buff[sizeof(char*)]; // Max local vars in function
#endif
not_null_tables_cache= used_tables_cache= 0;
const_item_cache= 1;
if (functype() != COND_AND_FUNC)
thd->thd_marker.emb_on_expr_nest= NULL;
/*
and_table_cache is the value that Item_cond_or() returns for
not_null_tables()
@ -4144,7 +4141,6 @@ Item_cond::fix_fields(THD *thd, Item **ref)
maybe_null=1;
}
thd->lex->current_select->cond_count+= list.elements;
thd->thd_marker.emb_on_expr_nest= save_emb_on_expr_nest;
fix_length_and_dec();
fixed= 1;
return FALSE;
@ -4414,6 +4410,17 @@ void Item_cond::neg_arguments(THD *thd)
}
void Item_cond_and::mark_as_condition_AND_part(TABLE_LIST *embedding)
{
List_iterator<Item> li(list);
Item *item;
while ((item=li++))
{
item->mark_as_condition_AND_part(embedding);
}
}
/**
Evaluation of AND(expr, expr, expr ...).

1
sql/item_cmpfunc.h
View File

@ -1816,6 +1816,7 @@ public:
return item;
}
Item *neg_transformer(THD *thd);
void mark_as_condition_AND_part(TABLE_LIST *embedding);
};
inline bool is_cond_and(Item *item)

3
sql/item_func.cc
View File

@ -152,11 +152,9 @@ Item_func::fix_fields(THD *thd, Item **ref)
{
DBUG_ASSERT(fixed == 0);
Item **arg,**arg_end;
TABLE_LIST *save_emb_on_expr_nest= thd->thd_marker.emb_on_expr_nest;
#ifndef EMBEDDED_LIBRARY // Avoid compiler warning
uchar buff[STACK_BUFF_ALLOC]; // Max argument in function
#endif
thd->thd_marker.emb_on_expr_nest= NULL;
used_tables_cache= not_null_tables_cache= 0;
const_item_cache=1;
@ -210,7 +208,6 @@ Item_func::fix_fields(THD *thd, Item **ref)
if (thd->is_error()) // An error inside fix_length_and_dec occured
return TRUE;
fixed= 1;
thd->thd_marker.emb_on_expr_nest= save_emb_on_expr_nest;
return FALSE;
}

7
sql/item_subselect.cc
View File

@ -1165,8 +1165,9 @@ bool Item_in_subselect::test_limit(st_select_lex_unit *unit_arg)
Item_in_subselect::Item_in_subselect(Item * left_exp,
st_select_lex *select_lex):
Item_exists_subselect(), left_expr_cache(0), first_execution(TRUE),
optimizer(0), pushed_cond_guards(NULL), in_strategy(0),
Item_exists_subselect(),
left_expr_cache(0), first_execution(TRUE),
optimizer(0), pushed_cond_guards(NULL), emb_on_expr_nest(NULL), in_strategy(0),
is_jtbm_merged(FALSE), is_flattenable_semijoin(FALSE),
is_registered_semijoin(FALSE),
upper_item(0)
@ -2395,6 +2396,7 @@ bool Item_in_subselect::fix_fields(THD *thd_arg, Item **ref)
uint outer_cols_num;
List<Item> *inner_cols;
if (in_strategy & SUBS_SEMI_JOIN)
return !( (*ref)= new Item_int(1));
@ -2449,7 +2451,6 @@ bool Item_in_subselect::fix_fields(THD *thd_arg, Item **ref)
return TRUE;
if (Item_subselect::fix_fields(thd_arg, ref))
return TRUE;
fixed= TRUE;
return FALSE;
}

10
sql/item_subselect.h
View File

@ -428,7 +428,6 @@ public:
join nest pointer - the predicate is an AND-part of ON expression
of a join nest
NULL - for all other locations
See also THD::emb_on_expr_nest.
*/
TABLE_LIST *emb_on_expr_nest;
/*
@ -489,7 +488,8 @@ public:
Item_in_subselect()
:Item_exists_subselect(), left_expr_cache(0), first_execution(TRUE),
abort_on_null(0), optimizer(0),
pushed_cond_guards(NULL), func(NULL), in_strategy(SUBS_NOT_TRANSFORMED),
pushed_cond_guards(NULL), func(NULL), emb_on_expr_nest(NULL),
in_strategy(SUBS_NOT_TRANSFORMED),
is_jtbm_merged(FALSE),
upper_item(0)
{}
@ -533,6 +533,12 @@ public:
user.
*/
int get_identifier();
void mark_as_condition_AND_part(TABLE_LIST *embedding)
{
emb_on_expr_nest= embedding;
}
friend class Item_ref_null_helper;
friend class Item_is_not_null_test;
friend class Item_in_optimizer;

6
sql/opt_subselect.cc
View File

@ -340,7 +340,7 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
!select_lex->is_part_of_union() && // 2
!select_lex->group_list.elements && !join->order && // 3
!join->having && !select_lex->with_sum_func && // 4
thd->thd_marker.emb_on_expr_nest && // 5
in_subs->emb_on_expr_nest && // 5
select_lex->outer_select()->join && // 6
parent_unit->first_select()->leaf_tables.elements && // 7
!in_subs->in_strategy && // 8
@ -353,7 +353,6 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
(void)subquery_types_allow_materialization(in_subs);
in_subs->emb_on_expr_nest= thd->thd_marker.emb_on_expr_nest;
in_subs->is_flattenable_semijoin= TRUE;
/* Register the subquery for further processing in flatten_subqueries() */
@ -434,10 +433,9 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
If the subquery is an AND-part of WHERE register for being processed
with jtbm strategy
*/
if (thd->thd_marker.emb_on_expr_nest == NO_JOIN_NEST &&
if (in_subs->emb_on_expr_nest == NO_JOIN_NEST &&
optimizer_flag(thd, OPTIMIZER_SWITCH_SEMIJOIN))
{
in_subs->emb_on_expr_nest= thd->thd_marker.emb_on_expr_nest;
in_subs->is_flattenable_semijoin= FALSE;
if (!in_subs->is_registered_semijoin)
{

7
sql/sql_base.cc
View File

@ -8276,7 +8276,6 @@ int setup_conds(THD *thd, TABLE_LIST *tables, List<TABLE_LIST> &leaves,
SELECT_LEX *select_lex= thd->lex->current_select;
Query_arena *arena= thd->stmt_arena, backup;
TABLE_LIST *table= NULL; // For HP compilers
TABLE_LIST *save_emb_on_expr_nest= thd->thd_marker.emb_on_expr_nest;
List_iterator<TABLE_LIST> ti(leaves);
/*
it_is_update set to TRUE when tables of primary SELECT_LEX (SELECT_LEX
@ -8317,7 +8316,6 @@ int setup_conds(THD *thd, TABLE_LIST *tables, List<TABLE_LIST> &leaves,
goto err_no_arena;
}
thd->thd_marker.emb_on_expr_nest= NO_JOIN_NEST;
if (*conds)
{
thd->where="where clause";
@ -8331,11 +8329,11 @@ int setup_conds(THD *thd, TABLE_LIST *tables, List<TABLE_LIST> &leaves,
*/
if ((*conds)->type() == Item::FIELD_ITEM && !derived)
wrap_ident(thd, conds);
(*conds)->mark_as_condition_AND_part(NO_JOIN_NEST);
if ((!(*conds)->fixed && (*conds)->fix_fields(thd, conds)) ||
(*conds)->check_cols(1))
goto err_no_arena;
}
thd->thd_marker.emb_on_expr_nest= save_emb_on_expr_nest;
/*
Apply fix_fields() to all ON clauses at all levels of nesting,
@ -8351,8 +8349,8 @@ int setup_conds(THD *thd, TABLE_LIST *tables, List<TABLE_LIST> &leaves,
if (embedded->on_expr)
{
/* Make a join an a expression */
thd->thd_marker.emb_on_expr_nest= embedded;
thd->where="on clause";
embedded->on_expr->mark_as_condition_AND_part(embedded);
if ((!embedded->on_expr->fixed &&
embedded->on_expr->fix_fields(thd, &embedded->on_expr)) ||
embedded->on_expr->check_cols(1))
@ -8376,7 +8374,6 @@ int setup_conds(THD *thd, TABLE_LIST *tables, List<TABLE_LIST> &leaves,
}
}
}
thd->thd_marker.emb_on_expr_nest= save_emb_on_expr_nest;
if (!thd->stmt_arena->is_conventional())
{

9
sql/sql_class.h
View File

@ -1600,15 +1600,6 @@ public:
/* container for handler's private per-connection data */
Ha_data ha_data[MAX_HA];
/* Place to store various things */
union
{
/*
Used by subquery optimizations, see Item_in_subselect::emb_on_expr_nest.
*/
TABLE_LIST *emb_on_expr_nest;
} thd_marker;
bool prepare_derived_at_open;
/*

2
sql/sql_parse.cc
View File

@ -5052,7 +5052,6 @@ static bool execute_sqlcom_select(THD *thd, TABLE_LIST *all_tables)
param->select_limit=
new Item_int((ulonglong) thd->variables.select_limit);
}
thd->thd_marker.emb_on_expr_nest= NULL;
if (!(res= open_and_lock_tables(thd, all_tables)))
{
if (lex->describe)
@ -5826,7 +5825,6 @@ void mysql_reset_thd_for_next_command(THD *thd, my_bool calculate_userstat)
thd->query_plan_flags= QPLAN_INIT;
thd->query_plan_fsort_passes= 0;
thd->thd_marker.emb_on_expr_nest= NULL;
/*
Because we come here only for start of top-statements, binlog format is

1
sql/sql_prepare.cc
View File

@ -1413,7 +1413,6 @@ static int mysql_test_select(Prepared_statement *stmt,
goto error;
thd->used_tables= 0; // Updated by setup_fields
thd->thd_marker.emb_on_expr_nest= 0;
/*
JOIN::prepare calls