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MDEV-38177: FULL OUTER JOIN Allowed JOIN Orders #4512

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1a6f718
MDEV-38177: FULL OUTER JOIN Allowed JOIN Orders
DaveGosselin-MariaDB Nov 24, 2025
2d8ad76
MDEV-38177: FULL OUTER JOIN Allowed JOIN Orders
DaveGosselin-MariaDB Dec 11, 2025
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66 changes: 65 additions & 1 deletion mysql-test/main/join.result
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Original file line number Diff line number Diff line change
Expand Up @@ -3969,6 +3969,8 @@ create table two (v int);
insert into two (v) values (2);
create table three (v int);
insert into three (v) values (3);
create table four (v int);
insert into three (v) values (4);
# (FULL)FULL to (INNER)INNER JOIN
select * from one full join two on one.v = two.v full join three on two.v = three.v where one.v is not null and two.v is not null and three.v is not null;
v v v
Expand Down Expand Up @@ -4006,9 +4008,11 @@ NULL 2 NULL
select * from one left join two on one.v = two.v full join three on two.v = three.v where three.v is not null;
v v v
NULL NULL 3
NULL NULL 4
select * from one left join two on one.v = two.v right join three on two.v = three.v;
v v v
NULL NULL 3
NULL NULL 4
# (LEFT)FULL to (LEFT)LEFT JOIN
insert into one (v) values (2),(3);
insert into two (v) values (1);
Expand All @@ -4032,5 +4036,65 @@ v v v
select * from three left join one on one.v = 1 left join two on two.v = 1;
v v v
1 1 1
drop table one, two, three;
# Interleaved JOIN checks
explain extended select * from one full outer join (two, three) on one.v=two.v;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE one UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE two UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE three UNKNOWN NULL NULL NULL NULL 0 0.00
Warnings:
Note 1003 select `test`.`one`.`v` AS `v`,`test`.`two`.`v` AS `v`,`test`.`three`.`v` AS `v` from `test`.`one` full join (`test`.`two` join `test`.`three`) on(multiple equal(`test`.`one`.`v`, `test`.`two`.`v`))
# ^^^ join order must be one, two, three
explain extended select * from (one, two) full outer join three on one.v=two.v;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE one UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE two UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE three UNKNOWN NULL NULL NULL NULL 0 0.00
Warnings:
Note 1003 select `test`.`one`.`v` AS `v`,`test`.`two`.`v` AS `v`,`test`.`three`.`v` AS `v` from `test`.`one` join `test`.`two` full join `test`.`three` on(multiple equal(`test`.`one`.`v`, `test`.`two`.`v`))
# ^^^ join order must be one, two, three
explain extended select * from one full outer join (three, two) on one.v=two.v;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE one UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE three UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE two UNKNOWN NULL NULL NULL NULL 0 0.00
Warnings:
Note 1003 select `test`.`one`.`v` AS `v`,`test`.`three`.`v` AS `v`,`test`.`two`.`v` AS `v` from `test`.`one` full join (`test`.`three` join `test`.`two`) on(multiple equal(`test`.`one`.`v`, `test`.`two`.`v`))
# ^^^ join order must be one, three, two
explain extended select * from (one, two t) full outer join (two v, three) on true;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE one UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE t UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE v UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE three UNKNOWN NULL NULL NULL NULL 0 0.00
Warnings:
Note 1003 select `test`.`one`.`v` AS `v`,`test`.`t`.`v` AS `v`,`test`.`v`.`v` AS `v`,`test`.`three`.`v` AS `v` from `test`.`one` join `test`.`two` `t` full join (`test`.`two` `v` join `test`.`three`) on(1)
# ^^^ join order must be one, t, v, three
explain extended select * from (one full outer join two on true) full outer join (three full outer join four on true) on true;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE one UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE two UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE three UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE four UNKNOWN NULL NULL NULL NULL 0 0.00
Warnings:
Note 1003 select `test`.`one`.`v` AS `v`,`test`.`two`.`v` AS `v`,`test`.`three`.`v` AS `v`,`test`.`four`.`v` AS `v` from `test`.`one` full join `test`.`two` on(1) full join (`test`.`three` full join `test`.`four` on(1)) on(1)
# ^^^ join order must be one, two, three, four
explain extended select * from (one full outer join two on true) inner join (three full outer join four on true);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE one UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE two UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE three system NULL NULL NULL NULL 1 100.00
1 SIMPLE four system NULL NULL NULL NULL 0 0.00 Const row not found
Warnings:
Note 1003 select `test`.`one`.`v` AS `v`,`test`.`two`.`v` AS `v`,1 AS `v`,NULL AS `v` from `test`.`one` full join `test`.`two` on(1)
# ^^^ join order must be one, two, three, four
explain extended select * from four full outer join (two full outer join three on true) on true;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE four system NULL NULL NULL NULL 0 0.00 Const row not found
1 SIMPLE two UNKNOWN NULL NULL NULL NULL 0 0.00
1 SIMPLE three UNKNOWN NULL NULL NULL NULL 0 0.00
Warnings:
Note 1003 select NULL AS `v`,`test`.`two`.`v` AS `v`,`test`.`three`.`v` AS `v` from (`test`.`two` full join `test`.`three` on(1))
# ^^^ join order must be four, two, three
drop table one, two, three, four;
# End of 12.3 tests
20 changes: 19 additions & 1 deletion mysql-test/main/join.test
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Original file line number Diff line number Diff line change
Expand Up @@ -2187,6 +2187,8 @@ create table two (v int);
insert into two (v) values (2);
create table three (v int);
insert into three (v) values (3);
create table four (v int);
insert into three (v) values (4);

--echo # (FULL)FULL to (INNER)INNER JOIN
select * from one full join two on one.v = two.v full join three on two.v = three.v where one.v is not null and two.v is not null and three.v is not null;
Expand Down Expand Up @@ -2223,7 +2225,23 @@ select * from three;
select * from one left join two on one.v = two.v full join three on two.v = three.v where three.v = 1;
select * from three left join one on one.v = 1 left join two on two.v = 1;

drop table one, two, three;
--echo # Interleaved JOIN checks
explain extended select * from one full outer join (two, three) on one.v=two.v;
--echo # ^^^ join order must be one, two, three
explain extended select * from (one, two) full outer join three on one.v=two.v;
--echo # ^^^ join order must be one, two, three
explain extended select * from one full outer join (three, two) on one.v=two.v;
--echo # ^^^ join order must be one, three, two
explain extended select * from (one, two t) full outer join (two v, three) on true;
--echo # ^^^ join order must be one, t, v, three
explain extended select * from (one full outer join two on true) full outer join (three full outer join four on true) on true;
--echo # ^^^ join order must be one, two, three, four
explain extended select * from (one full outer join two on true) inner join (three full outer join four on true);
--echo # ^^^ join order must be one, two, three, four
explain extended select * from four full outer join (two full outer join three on true) on true;
--echo # ^^^ join order must be four, two, three

drop table one, two, three, four;

# TODO fix PS protocol before end of FULL OUTER JOIN development
--enable_ps_protocol
Expand Down
4 changes: 2 additions & 2 deletions sql/item_subselect.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -4722,7 +4722,7 @@ void subselect_union_engine::print(String *str, enum_query_type query_type)
void subselect_uniquesubquery_engine::print(String *str,
enum_query_type query_type)
{
TABLE *table= tab->tab_list ? tab->tab_list->table : tab->table;
TABLE *table= tab->get_tab_list() ? tab->get_tab_list()->table : tab->table;
str->append(STRING_WITH_LEN("<primary_index_lookup>("));
tab->ref.items[0]->print(str, query_type);
str->append(STRING_WITH_LEN(" in "));
Expand Down Expand Up @@ -4775,7 +4775,7 @@ void subselect_uniquesubquery_engine::print(String *str)
void subselect_indexsubquery_engine::print(String *str,
enum_query_type query_type)
{
TABLE *table= tab->tab_list ? tab->tab_list->table : tab->table;
TABLE *table= tab->get_tab_list() ? tab->get_tab_list()->table : tab->table;
str->append(STRING_WITH_LEN("<index_lookup>("));
tab->ref.items[0]->print(str, query_type);
str->append(STRING_WITH_LEN(" in "));
Expand Down
12 changes: 6 additions & 6 deletions sql/opt_hints.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -1321,7 +1321,7 @@ bool Opt_hints_qb::set_join_hint_deps(JOIN *join,
bool hint_table_found= false;
for (uint i= 0; i < join->table_count; i++)
{
TABLE_LIST *table= join->join_tab[i].tab_list;
TABLE_LIST *table= join->join_tab[i].get_tab_list();
if (!compare_table_name(&tbl_name_and_qb, table))
{
hint_table_found= true;
Expand All @@ -1337,7 +1337,7 @@ bool Opt_hints_qb::set_join_hint_deps(JOIN *join,
// Hint tables are always dependent on preceding tables
join_tab->dependent |= hint_tab_map;
update_nested_join_deps(join, join_tab, hint_tab_map);
hint_tab_map |= join_tab->tab_list->get_map();
hint_tab_map |= join_tab->get_tab_list()->get_map();
break;
}
}
Expand All @@ -1356,7 +1356,7 @@ bool Opt_hints_qb::set_join_hint_deps(JOIN *join,
JOIN_TAB *join_tab= &join->join_tab[i];
const table_map dependent_tables=
get_other_dep(join, hint->hint_type, hint_tab_map,
join_tab->tab_list->get_map());
join_tab->get_tab_list()->get_map());
update_nested_join_deps(join, join_tab, dependent_tables);
join_tab->dependent |= dependent_tables;
}
Expand Down Expand Up @@ -1422,14 +1422,14 @@ bool Opt_hints_qb::set_join_hint_deps(JOIN *join,
void Opt_hints_qb::update_nested_join_deps(JOIN *join, const JOIN_TAB *hint_tab,
table_map hint_tab_map)
{
const TABLE_LIST *table= hint_tab->tab_list;
const TABLE_LIST *table= hint_tab->get_tab_list();
if (table->embedding)
{
for (uint i= 0; i < join->table_count; i++)
{
JOIN_TAB *tab= &join->join_tab[i];
/* Walk up the nested joins that tab->table is a part of */
for (TABLE_LIST *emb= tab->tab_list->embedding; emb; emb=emb->embedding)
for (TABLE_LIST *emb= tab->get_tab_list()->embedding; emb; emb=emb->embedding)
{
/*
Apply the rule only for outer joins. Semi-joins do not impose such
Expand All @@ -1439,7 +1439,7 @@ void Opt_hints_qb::update_nested_join_deps(JOIN *join, const JOIN_TAB *hint_tab,
{
const NESTED_JOIN *const nested_join= emb->nested_join;
/* Is hint_tab somewhere inside this nested join, too? */
if (hint_tab->embedding_map & nested_join->nj_map)
if (hint_tab->embedding_map & nested_join->get_nj_map())
{
/*
Yes, it is. Then, tab->table be also dependent on all outside
Expand Down
2 changes: 1 addition & 1 deletion sql/opt_trace.cc
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Expand Up @@ -660,7 +660,7 @@ void trace_plan_prefix(Json_writer_object *jsobj, JOIN *join, uint idx,
prefix_str.length(0);
for (uint i= join->const_tables; i < idx; i++)
{
TABLE_LIST *const tr= join->positions[i].table->tab_list;
TABLE_LIST *const tr= join->positions[i].table->get_tab_list();
if (!(tr->map & join_tables))
{
String str;
Expand Down
2 changes: 2 additions & 0 deletions sql/sql_parse.cc
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Expand Up @@ -8346,6 +8346,8 @@ TABLE_LIST *st_select_lex::nest_last_join(THD *thd)
if (prev_join_using)
ptr->join_using_fields= prev_join_using;
}
if (table->outer_join & JOIN_TYPE_FULL)
nested_join->is_foj= true;
}
nested_join->used_tables= nested_join->not_null_tables= (table_map) 0;
DBUG_RETURN(ptr);
Expand Down
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