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Fixed numerous problems for mutually recursive CTE.

Browse Source 
Actually mutually recursive CTE were not functional. Now the code
for mutually recursive CTE looks like functional, but still needs
re-writing.
Added many new test cases for mutually recursive CTE.
This commit is contained in:
Igor Babaev
2016-06-06 10:01:16 -07:00
parent 6c6c3af6aa
commit 0a6e6d705b
8 changed files with 653 additions and 32 deletions
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253
mysql-test/r/cte_recursive.result
View File

@ -372,9 +372,9 @@ id name dob father mother
100 Me 2000-01-01 20 30
20 Dad 1970-02-02 10 9
30 Mom 1975-03-03 8 7
9 Grandma Ann 1941-10-15 NULL NULL
10 Grandpa Bill 1940-04-05 NULL NULL
8 Grandpa Ben 1940-10-21 NULL NULL
9 Grandma Ann 1941-10-15 NULL NULL
7 Grandma Sally 1943-08-23 NULL 6
6 Grandgrandma Martha 1923-05-17 NULL NULL
with recursive
@ -406,6 +406,254 @@ h_name h_dob w_name w_dob
Dad 1970-02-02 Mom 1975-03-03
Grandpa Bill 1940-04-05 Grandma Ann 1941-10-15
Grandpa Ben 1940-10-21 Grandma Sally 1943-08-23
with recursive
ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
w_id, w_name, w_dob, w_father, w_mother)
as
(
select h.*, w.*
from folks h, folks w, coupled_ancestors a
where a.father = h.id AND a.mother = w.id
union
select h.*, w.*
from folks v, folks h, folks w
where v.name = 'Me' and
(v.father = h.id AND v.mother= w.id)
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select h_id, h_name, h_dob, h_father, h_mother
from ancestor_couples
union all
select w_id, w_name, w_dob, w_father, w_mother
from ancestor_couples
)
select h_name, h_dob, w_name, w_dob
from ancestor_couples;
h_name h_dob w_name w_dob
Dad 1970-02-02 Mom 1975-03-03
Grandpa Bill 1940-04-05 Grandma Ann 1941-10-15
Grandpa Ben 1940-10-21 Grandma Sally 1943-08-23
with recursive
ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
w_id, w_name, w_dob, w_father, w_mother)
as
(
select h.*, w.*
from folks h, folks w, coupled_ancestors a
where a.father = h.id AND a.mother = w.id
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select h_id, h_name, h_dob, h_father, h_mother
from ancestor_couples
union all
select w_id, w_name, w_dob, w_father, w_mother
from ancestor_couples
)
select h_name, h_dob, w_name, w_dob
from ancestor_couples;
h_name h_dob w_name w_dob
Dad 1970-02-02 Mom 1975-03-03
Grandpa Bill 1940-04-05 Grandma Ann 1941-10-15
Grandpa Ben 1940-10-21 Grandma Sally 1943-08-23
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select *
from ancestor_couple_ids;
h_id w_id
20 30
10 9
8 7
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, folks h, folks w
where c.h_id = h.id and c.w_id= w.id;
name dob name dob
Dad 1970-02-02 Mom 1975-03-03
Grandpa Bill 1940-04-05 Grandma Ann 1941-10-15
Grandpa Ben 1940-10-21 Grandma Sally 1943-08-23
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
where c.h_id = h.id and c.w_id= w.id;
name dob name dob
Dad 1970-02-02 Mom 1975-03-03
Grandpa Bill 1940-04-05 Grandma Ann 1941-10-15
Grandpa Ben 1940-10-21 Grandma Sally 1943-08-23
explain extended
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
where c.h_id = h.id and c.w_id= w.id;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 36 100.00
1 PRIMARY <derived3> ALL NULL NULL NULL NULL 468 100.00 Using where; Using join buffer (flat, BNL join)
1 PRIMARY <derived3> ALL NULL NULL NULL NULL 468 100.00 Using where; Using join buffer (incremental, BNL join)
3 SUBQUERY folks ALL NULL NULL NULL NULL 12 100.00 Using where
4 UNCACHEABLE UNION p ALL NULL NULL NULL NULL 12 100.00
4 UNCACHEABLE UNION <derived2> ALL NULL NULL NULL NULL 36 100.00 Using where; Using join buffer (flat, BNL join)
5 UNCACHEABLE UNION <derived2> ALL NULL NULL NULL NULL 2 100.00
5 UNCACHEABLE UNION p ALL NULL NULL NULL NULL 12 100.00 Using where; Using join buffer (flat, BNL join)
NULL UNION RESULT <union3,4,5> ALL NULL NULL NULL NULL NULL NULL
2 UNCACHEABLE SUBQUERY <derived3> ALL NULL NULL NULL NULL 36 100.00 Using where
Warnings:
Note 1003 with recursive ancestor_couple_ids as (select `a`.`father` AS `h_id`,`a`.`mother` AS `w_id` from `coupled_ancestors` `a` where ((`a`.`father` is not null) and (`a`.`mother` is not null)))coupled_ancestors as (select `test`.`folks`.`id` AS `id`,`test`.`folks`.`name` AS `name`,`test`.`folks`.`dob` AS `dob`,`test`.`folks`.`father` AS `father`,`test`.`folks`.`mother` AS `mother` from `test`.`folks` where (`test`.`folks`.`name` = 'Me') union all select `test`.`p`.`id` AS `id`,`test`.`p`.`name` AS `name`,`test`.`p`.`dob` AS `dob`,`test`.`p`.`father` AS `father`,`test`.`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestor_couple_ids` `fa` where (`fa`.`h_id` = `test`.`p`.`id`) union all select `test`.`p`.`id` AS `id`,`test`.`p`.`name` AS `name`,`test`.`p`.`dob` AS `dob`,`test`.`p`.`father` AS `father`,`test`.`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestor_couple_ids` `ma` where (`test`.`p`.`id` = `ma`.`w_id`)), select `h`.`name` AS `name`,`h`.`dob` AS `dob`,`w`.`name` AS `name`,`w`.`dob` AS `dob` from `ancestor_couple_ids` `c` join `coupled_ancestors` `h` join `coupled_ancestors` `w` where ((`h`.`id` = `c`.`h_id`) and (`w`.`id` = `c`.`w_id`))
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select *
from ancestor_couple_ids;
h_id w_id
20 30
10 9
8 7
NULL NULL
NULL NULL
NULL NULL
NULL 6
NULL NULL
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
where c.h_id = h.id and c.w_id= w.id;
name dob name dob
Dad 1970-02-02 Mom 1975-03-03
Grandpa Bill 1940-04-05 Grandma Ann 1941-10-15
Grandpa Ben 1940-10-21 Grandma Sally 1943-08-23
prepare stmt1 from "
with recursive
ancestors
@ -495,9 +743,9 @@ id name dob father mother
100 Me 2000-01-01 20 30
20 Dad 1970-02-02 10 9
30 Mom 1975-03-03 8 7
9 Grandma Ann 1941-10-15 NULL NULL
10 Grandpa Bill 1940-04-05 NULL NULL
8 Grandpa Ben 1940-10-21 NULL NULL
9 Grandma Ann 1941-10-15 NULL NULL
7 Grandma Sally 1943-08-23 NULL 6
6 Grandgrandma Martha 1923-05-17 NULL NULL
drop view v1,v2;
@ -571,7 +819,6 @@ id name dob father mother
100 Me 2000-01-01 20 30
20 Dad 1970-02-02 10 9
30 Mom 1975-03-03 8 7
9 Grandma Ann 1941-10-15 NULL NULL
10 Grandpa Bill 1940-04-05 NULL NULL
8 Grandpa Ben 1940-10-21 NULL NULL
9 Grandma Ann 1941-10-15 NULL NULL

215
mysql-test/t/cte_recursive.test
View File

@ -338,6 +338,221 @@ select h_name, h_dob, w_name, w_dob
from ancestor_couples;
with recursive
ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
w_id, w_name, w_dob, w_father, w_mother)
as
(
select h.*, w.*
from folks h, folks w, coupled_ancestors a
where a.father = h.id AND a.mother = w.id
union
select h.*, w.*
from folks v, folks h, folks w
where v.name = 'Me' and
(v.father = h.id AND v.mother= w.id)
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select h_id, h_name, h_dob, h_father, h_mother
from ancestor_couples
union all
select w_id, w_name, w_dob, w_father, w_mother
from ancestor_couples
)
select h_name, h_dob, w_name, w_dob
from ancestor_couples;
with recursive
ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
w_id, w_name, w_dob, w_father, w_mother)
as
(
select h.*, w.*
from folks h, folks w, coupled_ancestors a
where a.father = h.id AND a.mother = w.id
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select h_id, h_name, h_dob, h_father, h_mother
from ancestor_couples
union all
select w_id, w_name, w_dob, w_father, w_mother
from ancestor_couples
)
select h_name, h_dob, w_name, w_dob
from ancestor_couples;
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select *
from ancestor_couple_ids;
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, folks h, folks w
where c.h_id = h.id and c.w_id= w.id;
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
where c.h_id = h.id and c.w_id= w.id;
explain extended
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
where c.h_id = h.id and c.w_id= w.id;
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select *
from ancestor_couple_ids;
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
select a.father, a.mother
from coupled_ancestors a
),
coupled_ancestors (id, name, dob, father, mother)
as
(
select *
from folks
where name = 'Me'
union all
select p.*
from folks p, ancestor_couple_ids fa
where p.id = fa.h_id
union all
select p.*
from folks p, ancestor_couple_ids ma
where p.id = ma.w_id
)
select h.name, h.dob, w.name, w.dob
from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
where c.h_id = h.id and c.w_id= w.id;
prepare stmt1 from "
with recursive
ancestors

119
sql/sql_cte.h
View File

@ -87,6 +87,7 @@ public:
TABLE *result_table;
With_element(LEX_STRING *name,
List <LEX_STRING> list,
st_select_lex_unit *unit)
@ -164,6 +165,30 @@ public:
void reset_for_exec();
bool no_driving_recursive_is_set();
void set_as_driving_recursive();
bool is_driving_recursive();
void cleanup_driving_recursive();
void cleanup_incr_ready();
void set_as_incr_ready();
bool is_incr_ready();
bool all_incr_are_ready();
void cleanup_stabilized();
void set_as_stabilized();
bool is_stabilized();
bool all_are_stabilized();
void set_result_table(TABLE *tab) { result_table= tab; }
friend class With_clause;
@ -202,6 +227,9 @@ private:
table_map unrestricted;
table_map with_prepared_anchor;
table_map cleaned;
table_map driving_recursive;
table_map incr_ready;
table_map stabilized;
public:
/* If true the specifier RECURSIVE is present in the with clause */
@ -212,6 +240,7 @@ public:
embedding_with_clause(emb_with_clause), next_with_clause(NULL),
dependencies_are_checked(false),
unrestricted(0), with_prepared_anchor(0), cleaned(0),
driving_recursive(0), incr_ready(0), stabilized(0),
with_recursive(recursive_fl)
{ last_next= &first_elem; }
@ -287,6 +316,7 @@ bool With_element::is_cleaned()
return owner->cleaned & get_elem_map();
}
inline
void With_element::mark_as_cleaned()
{
@ -300,8 +330,96 @@ void With_element::reset_for_exec()
level= 0;
owner->with_prepared_anchor&= ~mutually_recursive;
owner->cleaned&= ~get_elem_map();
owner->driving_recursive&= ~get_elem_map();
cleanup_incr_ready();
cleanup_stabilized();
}
inline
bool With_element::no_driving_recursive_is_set()
{
return !(owner->driving_recursive & mutually_recursive);
}
inline
void With_element::set_as_driving_recursive()
{
owner->driving_recursive|= get_elem_map();
}
inline
bool With_element::is_driving_recursive()
{
return owner->driving_recursive & get_elem_map();
}
inline
void With_element::cleanup_driving_recursive()
{
owner->driving_recursive&= ~mutually_recursive;
}
inline
void With_element::cleanup_incr_ready()
{
owner->incr_ready&= ~mutually_recursive;
}
inline
void With_element::set_as_incr_ready()
{
owner->incr_ready|= get_elem_map();
}
inline
bool With_element::is_incr_ready()
{
return owner->incr_ready & get_elem_map();
}
inline
bool With_element::all_incr_are_ready()
{
return (owner->incr_ready & mutually_recursive) == mutually_recursive;
}
inline
void With_element::cleanup_stabilized()
{
owner->stabilized&= ~mutually_recursive;
}
inline
void With_element::set_as_stabilized()
{
owner->stabilized|= get_elem_map();
}
inline
bool With_element::is_stabilized()
{
return owner->stabilized & get_elem_map();
}
inline
bool With_element::all_are_stabilized()
{
return (owner->stabilized & mutually_recursive) == mutually_recursive;
}
inline
void st_select_lex_unit::set_with_clause(With_clause *with_cl)
{
@ -310,6 +428,7 @@ void st_select_lex_unit::set_with_clause(With_clause *with_cl)
with_clause->set_owner(this);
}
inline
void st_select_lex::set_with_clause(With_clause *with_clause)
{

13
sql/sql_derived.cc
View File

@ -661,7 +661,10 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
derived->derived_result->set_unit(unit);
derived->table= derived->derived_result->table;
if (derived->is_with_table_recursive_reference())
{
unit->with_element->rec_result->rec_tables.push_back(derived->table);
derived->table->is_rec_table= true;
}
}
DBUG_ASSERT(derived->table || res);
goto exit;
@ -945,9 +948,10 @@ bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived)
{
DBUG_ENTER("mysql_derived_fill");
SELECT_LEX_UNIT *unit= derived->get_unit();
bool derived_is_recursive= derived->is_recursive_with_table();
bool res= FALSE;
if (derived->is_recursive_with_table() && unit->executed)
if (derived_is_recursive && derived->with->all_are_stabilized())
{
TABLE *src= unit->with_element->rec_result->table;
TABLE *dest= derived->table;
@ -955,17 +959,18 @@ bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived)
DBUG_RETURN(res);
}
if (unit->executed && !unit->uncacheable && !unit->describe)
if (unit->executed && !unit->uncacheable && !unit->describe &&
!derived_is_recursive)
DBUG_RETURN(FALSE);
/*check that table creation passed without problems. */
DBUG_ASSERT(derived->table && derived->table->is_created());
SELECT_LEX *first_select= unit->first_select();
select_union *derived_result= derived->derived_result;
SELECT_LEX *save_current_select= lex->current_select;
if (unit->is_union())
if (unit->is_union() || derived_is_recursive)
{
// execute union without clean up
if (derived->is_recursive_with_table())
if (derived_is_recursive)
unit->with_element->set_result_table(derived->table);
res= unit->exec();
}

13
sql/sql_select.cc
View File

@ -11605,7 +11605,12 @@ bool JOIN_TAB::preread_init()
}
/* Materialize derived table/view. */
if ((!derived->get_unit()->executed || derived->is_recursive_with_table()) &&
if ((!derived->get_unit()->executed ||
(derived->is_recursive_with_table() &&
(!derived->is_with_table_recursive_reference() ||
(!derived->with->is_driving_recursive() &&
!derived->with->is_incr_ready()) &&
!derived->with->all_are_stabilized()))) &&
mysql_handle_single_derived(join->thd->lex,
derived, DT_CREATE | DT_FILL))
return TRUE;
@ -18236,7 +18241,8 @@ sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
flush_dups_table->sj_weedout_delete_rows();
}
if (!join_tab->preread_init_done && join_tab->preread_init())
if ((!join_tab->preread_init_done || join_tab->table->is_rec_table) &&
join_tab->preread_init())
DBUG_RETURN(NESTED_LOOP_ERROR);
join->return_tab= join_tab;
@ -19189,7 +19195,8 @@ int join_init_read_record(JOIN_TAB *tab)
report_error(tab->table, error);
return 1;
}
if (!tab->preread_init_done && tab->preread_init())
if ((!tab->preread_init_done || tab->table->is_rec_table) &&
tab->preread_init())
return 1;
if (init_read_record(&tab->read_record, tab->join->thd, tab->table,
tab->select, tab->filesort_result, 1,1, FALSE))

54
sql/sql_union.cc
View File

@ -244,6 +244,7 @@ select_union_recursive::create_result_table(THD *thd_arg,
if (rec_tables.push_back(rec_table))
return true;
rec_table->is_rec_table= true;
return false;
}
@ -494,7 +495,7 @@ bool st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
/* Global option */
if (is_union_select)
if (is_union_select || is_recursive)
{
if (is_union() && !union_needs_tmp_table())
{
@ -587,7 +588,7 @@ bool st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
Use items list of underlaid select for derived tables to preserve
information about fields lengths and exact types
*/
if (!is_union_select)
if (!is_union_select && !is_recursive)
types= first_sl->item_list;
else if (sl == first_sl)
{
@ -917,8 +918,9 @@ bool st_select_lex_unit::exec()
bool first_execution= !executed;
DBUG_ENTER("st_select_lex_unit::exec");
bool was_executed= executed;
bool is_recursive= with_element && with_element->is_recursive;
if (executed && !uncacheable && !describe)
if (executed && !uncacheable && !describe && !is_recursive)
DBUG_RETURN(FALSE);
executed= 1;
if (!(uncacheable & ~UNCACHEABLE_EXPLAIN) && item)
@ -934,7 +936,7 @@ bool st_select_lex_unit::exec()
if (saved_error)
DBUG_RETURN(saved_error);
if (with_element && with_element->is_recursive && !describe)
if (is_recursive && !describe)
{
saved_error= exec_recursive();
DBUG_RETURN(saved_error);
@ -1174,10 +1176,7 @@ bool st_select_lex_unit::exec_recursive()
TABLE *result_table= with_element->result_table;
ha_rows examined_rows= 0;
bool unrestricted= with_element->is_unrestricted();
bool no_more_iterations= false;
bool with_anchor= with_element->with_anchor;
st_select_lex *first_sl= first_select();
st_select_lex *barrier= with_anchor ? first_recursive_sel : NULL;
uint max_level= thd->variables.max_recursion_level;
List_iterator_fast<TABLE> li(with_element->rec_result->rec_tables);
TABLE *rec_table;
@ -1186,9 +1185,31 @@ bool st_select_lex_unit::exec_recursive()
do
{
st_select_lex *first_sl;
st_select_lex *barrier;
if ((saved_error= incr_table->file->ha_delete_all_rows()))
goto err;
if (with_element->no_driving_recursive_is_set())
with_element->set_as_driving_recursive();
if (with_element->level == 0)
{
first_sl= first_select();
if (with_anchor)
barrier= first_recursive_sel;
else
barrier= NULL;
}
else
{
first_sl= first_recursive_sel;
barrier= NULL;
}
if (with_element->all_incr_are_ready())
with_element->cleanup_incr_ready();
for (st_select_lex *sl= first_sl ; sl != barrier; sl= sl->next_select())
{
thd->lex->current_select= sl;
@ -1211,16 +1232,12 @@ bool st_select_lex_unit::exec_recursive()
}
}
if (with_element->level == 0)
{
first_sl= first_recursive_sel;
barrier= NULL;
}
with_element->set_as_incr_ready();
incr_table->file->info(HA_STATUS_VARIABLE);
if (incr_table->file->stats.records == 0 ||
with_element->level + 1 == max_level)
no_more_iterations= true;
with_element->set_as_stabilized();
else
with_element->level++;
@ -1231,12 +1248,21 @@ bool st_select_lex_unit::exec_recursive()
!unrestricted)))
goto err;
}
} while (!no_more_iterations);
if (!with_element->is_driving_recursive())
break;
} while (!with_element->all_are_stabilized());
if (with_element->is_driving_recursive())
{
TABLE *table= with_element->rec_result->table;
if ((saved_error= table->insert_all_rows_into(thd,
result_table,
true)))
goto err;
with_element->cleanup_driving_recursive();
}
thd->lex->current_select= lex_select_save;
err:

3
sql/table.cc
View File

@ -7328,7 +7328,8 @@ bool TABLE_LIST::init_derived(THD *thd, bool init_view)
if (!is_materialized_derived() && first_select->is_mergeable() &&
optimizer_flag(thd, OPTIMIZER_SWITCH_DERIVED_MERGE) &&
!(thd->lex->sql_command == SQLCOM_UPDATE_MULTI ||
thd->lex->sql_command == SQLCOM_DELETE_MULTI))
thd->lex->sql_command == SQLCOM_DELETE_MULTI) &&
!is_recursive_with_table())
set_merged_derived();
else
set_materialized_derived();

1
sql/table.h
View File

@ -1244,6 +1244,7 @@ public:
bool alias_name_used; /* true if table_name is alias */
bool get_fields_in_item_tree; /* Signal to fix_field */
bool m_needs_reopen;
bool is_rec_table;
private:
bool created; /* For tmp tables. TRUE <=> tmp table was actually created.*/
public: