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nexedi
MariaDB
Commits
b2c57ced
Commit
b2c57ced
authored
Apr 25, 2010
by
Sergey Petrunya
Browse files
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Code cleanup in subquery optimizations
parent
30bac798
Changes
6
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6 changed files
with
48 additions
and
55 deletions
+48
-55
sql/item_subselect.h
sql/item_subselect.h
+13
-1
sql/opt_subselect.cc
sql/opt_subselect.cc
+16
-34
sql/opt_subselect.h
sql/opt_subselect.h
+7
-1
sql/sql_select.cc
sql/sql_select.cc
+1
-7
sql/sql_select.h
sql/sql_select.h
+2
-10
sql/table.h
sql/table.h
+9
-2
No files found.
sql/item_subselect.h
View file @
b2c57ced
...
@@ -382,8 +382,20 @@ class Item_in_subselect :public Item_exists_subselect
...
@@ -382,8 +382,20 @@ class Item_in_subselect :public Item_exists_subselect
};
};
enum_exec_method
exec_method
;
enum_exec_method
exec_method
;
/* JTBM: temporary measure to tell JTBM predicates from SJ predicates */
/*
JTBM: temporary measure to tell JTBM predicates from SJ predicates
psergey-jtbm-todo: can't we do without this?
- either remove it altogether
- or put into enum_exec_method
We can't remove it altogether as it is used to classify contents in
join->sj_subselects.
*/
bool
convert_to_semi_join
;
bool
convert_to_semi_join
;
/*
Cost to populate the temporary table (set on if-needed basis).
*/
double
startup_cost
;
double
startup_cost
;
bool
*
get_cond_guard
(
int
i
)
bool
*
get_cond_guard
(
int
i
)
...
...
sql/opt_subselect.cc
View file @
b2c57ced
...
@@ -2,7 +2,7 @@
...
@@ -2,7 +2,7 @@
@file
@file
@brief
@brief
S
ubquery optimization code here.
S
emi-join subquery optimizations code
*/
*/
...
@@ -228,15 +228,17 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
...
@@ -228,15 +228,17 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
if
(
in_subs
->
exec_method
==
Item_in_subselect
::
NOT_TRANSFORMED
)
if
(
in_subs
->
exec_method
==
Item_in_subselect
::
NOT_TRANSFORMED
)
in_subs
->
exec_method
=
Item_in_subselect
::
MATERIALIZATION
;
in_subs
->
exec_method
=
Item_in_subselect
::
MATERIALIZATION
;
// psergey-jtbm: "if we're top-level, register for
/*
// conversion-to-join-tab".
If the subquery is an AND-part of WHERE register for being processed
with jtbm strategy
*/
if
(
in_subs
->
exec_method
==
Item_in_subselect
::
MATERIALIZATION
&&
if
(
in_subs
->
exec_method
==
Item_in_subselect
::
MATERIALIZATION
&&
thd
->
thd_marker
.
emb_on_expr_nest
==
(
TABLE_LIST
*
)
0x1
)
thd
->
thd_marker
.
emb_on_expr_nest
==
(
TABLE_LIST
*
)
0x1
)
{
{
in_subs
->
emb_on_expr_nest
=
thd
->
thd_marker
.
emb_on_expr_nest
;
in_subs
->
emb_on_expr_nest
=
thd
->
thd_marker
.
emb_on_expr_nest
;
in_subs
->
convert_to_semi_join
=
FALSE
;
//JTBM
in_subs
->
convert_to_semi_join
=
FALSE
;
select_lex
->
outer_select
()
->
select_lex
->
outer_select
()
->
join
->
sj_subselects
.
append
(
thd
->
mem_root
,
in_subs
);
//JTBM
join
->
sj_subselects
.
append
(
thd
->
mem_root
,
in_subs
);
}
}
}
}
...
@@ -406,6 +408,8 @@ static bool make_in_exists_conversion(THD *thd, JOIN *join, Item_in_subselect *i
...
@@ -406,6 +408,8 @@ static bool make_in_exists_conversion(THD *thd, JOIN *join, Item_in_subselect *i
}
}
DBUG_RETURN
(
FALSE
);
DBUG_RETURN
(
FALSE
);
}
}
/*
/*
Convert semi-join subquery predicates into semi-join join nests
Convert semi-join subquery predicates into semi-join join nests
...
@@ -513,29 +517,6 @@ bool convert_join_subqueries_to_semijoins(JOIN *join)
...
@@ -513,29 +517,6 @@ bool convert_join_subqueries_to_semijoins(JOIN *join)
// #tables-in-parent-query + #tables-in-subquery < MAX_TABLES
// #tables-in-parent-query + #tables-in-subquery < MAX_TABLES
/* Replace all subqueries to be flattened with Item_int(1) */
/* Replace all subqueries to be flattened with Item_int(1) */
arena
=
thd
->
activate_stmt_arena_if_needed
(
&
backup
);
arena
=
thd
->
activate_stmt_arena_if_needed
(
&
backup
);
#if 0
for (in_subq= join->sj_subselects.front();
in_subq != in_subq_end &&
join->tables + (*in_subq)->unit->first_select()->join->tables < MAX_TABLES;
in_subq++)
{
Item **tree= ((*in_subq)->emb_on_expr_nest == (TABLE_LIST*)1)?
&join->conds : &((*in_subq)->emb_on_expr_nest->on_expr);
Item *replace_me= *in_subq;
/*
JTBM: the subquery was already mapped with Item_in_optimizer, so we
should search for that, not for original Item_in_subselect.
TODO: what about delaying that rewrite until here?
*/
if (!(*in_subq)->convert_to_semi_join)
{
replace_me= (*in_subq)->optimizer;
}
if (replace_where_subcondition(join, tree, replace_me, new Item_int(1),
FALSE))
DBUG_RETURN(TRUE); /* purecov: inspected */
}
#endif
for
(
in_subq
=
join
->
sj_subselects
.
front
();
for
(
in_subq
=
join
->
sj_subselects
.
front
();
in_subq
!=
in_subq_end
&&
in_subq
!=
in_subq_end
&&
...
@@ -543,8 +524,6 @@ bool convert_join_subqueries_to_semijoins(JOIN *join)
...
@@ -543,8 +524,6 @@ bool convert_join_subqueries_to_semijoins(JOIN *join)
in_subq
++
)
in_subq
++
)
{
{
bool
remove_item
=
TRUE
;
bool
remove_item
=
TRUE
;
//psergey-jtbm: todo: here: check if we should convert to semi-join or
// to JTBM nest.
if
((
*
in_subq
)
->
convert_to_semi_join
)
if
((
*
in_subq
)
->
convert_to_semi_join
)
{
{
if
(
convert_subq_to_sj
(
join
,
*
in_subq
))
if
(
convert_subq_to_sj
(
join
,
*
in_subq
))
...
@@ -668,6 +647,7 @@ void get_temptable_params(Item_in_subselect *item, ha_rows *out_rows,
...
@@ -668,6 +647,7 @@ void get_temptable_params(Item_in_subselect *item, ha_rows *out_rows,
*
scan_time
=
data_size
/
IO_SIZE
+
2
;
*
scan_time
=
data_size
/
IO_SIZE
+
2
;
}
}
/**
/**
@brief Replaces an expression destructively inside the expression tree of
@brief Replaces an expression destructively inside the expression tree of
the WHERE clase.
the WHERE clase.
...
@@ -685,6 +665,7 @@ void get_temptable_params(Item_in_subselect *item, ha_rows *out_rows,
...
@@ -685,6 +665,7 @@ void get_temptable_params(Item_in_subselect *item, ha_rows *out_rows,
@return <code>true</code> if there was an error, <code>false</code> if
@return <code>true</code> if there was an error, <code>false</code> if
successful.
successful.
*/
*/
static
bool
replace_where_subcondition
(
JOIN
*
join
,
Item
**
expr
,
static
bool
replace_where_subcondition
(
JOIN
*
join
,
Item
**
expr
,
Item
*
old_cond
,
Item
*
new_cond
,
Item
*
old_cond
,
Item
*
new_cond
,
bool
do_fix_fields
)
bool
do_fix_fields
)
...
@@ -920,8 +901,7 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)
...
@@ -920,8 +901,7 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)
/* 3. Remove the original subquery predicate from the WHERE/ON */
/* 3. Remove the original subquery predicate from the WHERE/ON */
// The subqueries were replaced for Item_int(1) earlier
// The subqueries were replaced for Item_int(1) earlier
subq_pred
->
exec_method
=
subq_pred
->
exec_method
=
Item_in_subselect
::
SEMI_JOIN
;
// for subsequent executions
Item_in_subselect
::
SEMI_JOIN
;
// for subsequent executions
/*TODO: also reset the 'with_subselect' there. */
/*TODO: also reset the 'with_subselect' there. */
/* n. Adjust the parent_join->tables counter */
/* n. Adjust the parent_join->tables counter */
...
@@ -1046,7 +1026,7 @@ static bool convert_subq_to_jtbm(JOIN *parent_join,
...
@@ -1046,7 +1026,7 @@ static bool convert_subq_to_jtbm(JOIN *parent_join,
SELECT_LEX
*
parent_lex
=
parent_join
->
select_lex
;
SELECT_LEX
*
parent_lex
=
parent_join
->
select_lex
;
List
<
TABLE_LIST
>
*
emb_join_list
=
&
parent_lex
->
top_join_list
;
List
<
TABLE_LIST
>
*
emb_join_list
=
&
parent_lex
->
top_join_list
;
TABLE_LIST
*
emb_tbl_nest
=
NULL
;
// will change when we learn to handle outer joins
TABLE_LIST
*
emb_tbl_nest
=
NULL
;
// will change when we learn to handle outer joins
TABLE_LIST
*
tl
;
//, *last_leaf;
TABLE_LIST
*
tl
;
DBUG_ENTER
(
"convert_subq_to_jtbm"
);
DBUG_ENTER
(
"convert_subq_to_jtbm"
);
if
(
subq_pred
->
setup_engine
(
TRUE
))
if
(
subq_pred
->
setup_engine
(
TRUE
))
...
@@ -1071,7 +1051,6 @@ static bool convert_subq_to_jtbm(JOIN *parent_join,
...
@@ -1071,7 +1051,6 @@ static bool convert_subq_to_jtbm(JOIN *parent_join,
jtbm
->
join_list
=
emb_join_list
;
jtbm
->
join_list
=
emb_join_list
;
jtbm
->
embedding
=
emb_tbl_nest
;
jtbm
->
embedding
=
emb_tbl_nest
;
jtbm
->
alias
=
(
char
*
)
"(jtbm)"
;
jtbm
->
jtbm_subselect
=
subq_pred
;
jtbm
->
jtbm_subselect
=
subq_pred
;
jtbm
->
nested_join
=
NULL
;
jtbm
->
nested_join
=
NULL
;
...
@@ -1504,6 +1483,7 @@ bool optimize_semijoin_nests(JOIN *join, table_map all_table_map)
...
@@ -1504,6 +1483,7 @@ bool optimize_semijoin_nests(JOIN *join, table_map all_table_map)
DBUG_RETURN
(
FALSE
);
DBUG_RETURN
(
FALSE
);
}
}
/*
/*
Get estimated record length for semi-join materialization temptable
Get estimated record length for semi-join materialization temptable
...
@@ -1627,6 +1607,7 @@ bool find_eq_ref_candidate(TABLE *table, table_map sj_inner_tables)
...
@@ -1627,6 +1607,7 @@ bool find_eq_ref_candidate(TABLE *table, table_map sj_inner_tables)
return
FALSE
;
return
FALSE
;
}
}
/*
/*
Do semi-join optimization step after we've added a new tab to join prefix
Do semi-join optimization step after we've added a new tab to join prefix
...
@@ -3762,6 +3743,7 @@ static void remove_subq_pushed_predicates(JOIN *join, Item **where)
...
@@ -3762,6 +3743,7 @@ static void remove_subq_pushed_predicates(JOIN *join, Item **where)
}
}
}
}
int
do_jtbm_materialization_if_needed
(
JOIN_TAB
*
tab
)
int
do_jtbm_materialization_if_needed
(
JOIN_TAB
*
tab
)
{
{
Item_in_subselect
*
in_subs
;
Item_in_subselect
*
in_subs
;
...
...
sql/opt_subselect.h
View file @
b2c57ced
/* */
/*
Semi-join subquery optimization code definitions
*/
#ifdef USE_PRAGMA_INTERFACE
#ifdef USE_PRAGMA_INTERFACE
#pragma interface
/* gcc class implementation */
#pragma interface
/* gcc class implementation */
...
@@ -365,4 +367,8 @@ int clear_sj_tmp_tables(JOIN *join);
...
@@ -365,4 +367,8 @@ int clear_sj_tmp_tables(JOIN *join);
int
rewrite_to_index_subquery_engine
(
JOIN
*
join
);
int
rewrite_to_index_subquery_engine
(
JOIN
*
join
);
void
get_temptable_params
(
Item_in_subselect
*
item
,
ha_rows
*
out_rows
,
ha_rows
*
scan_time
);
int
do_jtbm_materialization_if_needed
(
JOIN_TAB
*
tab
);
sql/sql_select.cc
View file @
b2c57ced
...
@@ -243,10 +243,6 @@ join_read_record_no_init(JOIN_TAB *tab);
...
@@ -243,10 +243,6 @@ join_read_record_no_init(JOIN_TAB *tab);
Item_equal
*
find_item_equal
(
COND_EQUAL
*
cond_equal
,
Field
*
field
,
Item_equal
*
find_item_equal
(
COND_EQUAL
*
cond_equal
,
Field
*
field
,
bool
*
inherited_fl
);
bool
*
inherited_fl
);
void
get_temptable_params
(
Item_in_subselect
*
item
,
ha_rows
*
out_rows
,
ha_rows
*
scan_time
);
int
do_jtbm_materialization_if_needed
(
JOIN_TAB
*
tab
);
/**
/**
This handles SELECT with and without UNION.
This handles SELECT with and without UNION.
*/
*/
...
@@ -2634,7 +2630,6 @@ make_join_statistics(JOIN *join, TABLE_LIST *tables_arg, COND *conds,
...
@@ -2634,7 +2630,6 @@ make_join_statistics(JOIN *join, TABLE_LIST *tables_arg, COND *conds,
no_rows_const_tables
|=
table
->
map
;
no_rows_const_tables
|=
table
->
map
;
}
}
}
}
//psergey-todo: inject jtbm JOIN_TABS here.
stat_vector
[
i
]
=
0
;
stat_vector
[
i
]
=
0
;
join
->
outer_join
=
outer_join
;
join
->
outer_join
=
outer_join
;
...
@@ -7723,7 +7718,7 @@ void JOIN_TAB::cleanup()
...
@@ -7723,7 +7718,7 @@ void JOIN_TAB::cleanup()
table
->
file
->
extra
(
HA_EXTRA_NO_KEYREAD
);
table
->
file
->
extra
(
HA_EXTRA_NO_KEYREAD
);
}
}
table
->
file
->
ha_index_or_rnd_end
();
table
->
file
->
ha_index_or_rnd_end
();
//psergey-jtbm2:
if
(
table
->
pos_in_table_list
&&
if
(
table
->
pos_in_table_list
&&
table
->
pos_in_table_list
->
jtbm_subselect
)
table
->
pos_in_table_list
->
jtbm_subselect
)
{
{
...
@@ -11570,7 +11565,6 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
...
@@ -11570,7 +11565,6 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
{
{
key_part_info
->
null_bit
=
0
;
key_part_info
->
null_bit
=
0
;
key_part_info
->
field
=
*
reg_field
;
key_part_info
->
field
=
*
reg_field
;
//psergey-jtbm:
(
*
reg_field
)
->
flags
|=
PART_KEY_FLAG
;
(
*
reg_field
)
->
flags
|=
PART_KEY_FLAG
;
if
(
key_part_info
==
keyinfo
->
key_part
)
if
(
key_part_info
==
keyinfo
->
key_part
)
(
*
reg_field
)
->
key_start
.
set_bit
(
0
);
(
*
reg_field
)
->
key_start
.
set_bit
(
0
);
...
...
sql/sql_select.h
View file @
b2c57ced
...
@@ -1552,18 +1552,11 @@ class JOIN :public Sql_alloc
...
@@ -1552,18 +1552,11 @@ class JOIN :public Sql_alloc
bool
optimized
;
///< flag to avoid double optimization in EXPLAIN
bool
optimized
;
///< flag to avoid double optimization in EXPLAIN
/*
/*
Subqueries that will need to be converted to semi-join nests
(the list
Subqueries that will need to be converted to semi-join nests
, including
is emptied when conversion is done
those converted to jtbm nests. The list is emptied when conversion is done.
*/
*/
Array
<
Item_in_subselect
>
sj_subselects
;
Array
<
Item_in_subselect
>
sj_subselects
;
/*
Subqueries that will need to be converted to JOIN_TABs
(Note this is different from the above in the respect that it's part
of WHERE clause or something like that?)
*/
//Array<Item_in_subselect> jtbm_subselects;
/* Temporary tables used to weed-out semi-join duplicates */
/* Temporary tables used to weed-out semi-join duplicates */
List
<
TABLE
>
sj_tmp_tables
;
List
<
TABLE
>
sj_tmp_tables
;
List
<
SJ_MATERIALIZATION_INFO
>
sjm_info_list
;
List
<
SJ_MATERIALIZATION_INFO
>
sjm_info_list
;
...
@@ -1586,7 +1579,6 @@ class JOIN :public Sql_alloc
...
@@ -1586,7 +1579,6 @@ class JOIN :public Sql_alloc
JOIN
(
THD
*
thd_arg
,
List
<
Item
>
&
fields_arg
,
ulonglong
select_options_arg
,
JOIN
(
THD
*
thd_arg
,
List
<
Item
>
&
fields_arg
,
ulonglong
select_options_arg
,
select_result
*
result_arg
)
select_result
*
result_arg
)
:
fields_list
(
fields_arg
),
sj_subselects
(
thd_arg
->
mem_root
,
4
)
:
fields_list
(
fields_arg
),
sj_subselects
(
thd_arg
->
mem_root
,
4
)
//jtbm_subselects(thd_arg->mem_root, 4)
{
{
init
(
thd_arg
,
fields_arg
,
select_options_arg
,
result_arg
);
init
(
thd_arg
,
fields_arg
,
select_options_arg
,
result_arg
);
}
}
...
...
sql/table.h
View file @
b2c57ced
...
@@ -1131,7 +1131,7 @@ class Item_in_subselect;
...
@@ -1131,7 +1131,7 @@ class Item_in_subselect;
1) table (TABLE_LIST::view == NULL)
1) table (TABLE_LIST::view == NULL)
- base table
- base table
(TABLE_LIST::derived == NULL)
(TABLE_LIST::derived == NULL)
- subquery - TABLE_LIST::table is a temp table
-
FROM-clause
subquery - TABLE_LIST::table is a temp table
(TABLE_LIST::derived != NULL)
(TABLE_LIST::derived != NULL)
- information schema table
- information schema table
(TABLE_LIST::schema_table != NULL)
(TABLE_LIST::schema_table != NULL)
...
@@ -1150,6 +1150,8 @@ class Item_in_subselect;
...
@@ -1150,6 +1150,8 @@ class Item_in_subselect;
(TABLE_LIST::natural_join != NULL)
(TABLE_LIST::natural_join != NULL)
- JOIN ... USING
- JOIN ... USING
(TABLE_LIST::join_using_fields != NULL)
(TABLE_LIST::join_using_fields != NULL)
- semi-join nest (sj_on_expr!= NULL && sj_subq_pred!=NULL)
4) jtbm semi-join (jtbm_subselect != NULL)
*/
*/
class
Index_hint
;
class
Index_hint
;
...
@@ -1193,8 +1195,13 @@ struct TABLE_LIST
...
@@ -1193,8 +1195,13 @@ struct TABLE_LIST
table_map
sj_inner_tables
;
table_map
sj_inner_tables
;
/* Number of IN-compared expressions */
/* Number of IN-compared expressions */
uint
sj_in_exprs
;
uint
sj_in_exprs
;
/* If this is a non-jtbm semi-join nest: corresponding subselect predicate */
Item_in_subselect
*
sj_subq_pred
;
Item_in_subselect
*
sj_subq_pred
;
/* If this is a jtbm semi-join object: corresponding subselect predicate */
Item_in_subselect
*
jtbm_subselect
;
Item_in_subselect
*
jtbm_subselect
;
SJ_MATERIALIZATION_INFO
*
sj_mat_info
;
SJ_MATERIALIZATION_INFO
*
sj_mat_info
;
/*
/*
...
...
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