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MDEV-38045 Implement QB_NAME hint with path syntax for nested query blocks #4482

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MDEV-38045 Implement QB_NAME hint with path syntax for nested query blocks #4482

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c1f3882
MDEV-38045: Implement implicit query block names for optimizer hints
Olernov Nov 8, 2025
a6ceac5
MDEV-38045: Implement QB_NAME hint with path syntax for nested query …
Olernov Dec 2, 2025
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48 changes: 42 additions & 6 deletions mysql-test/main/opt_hints.result
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Original file line number Diff line number Diff line change
Expand Up @@ -439,6 +439,18 @@ id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 ref f1 f1 8 test.t3.f1,test.t3.f2 2 50.00 Using where; FirstMatch(t3)
Warnings:
Note 1003 update /*+ BKA(`t2`@`select#2`) NO_BNL(`t1`@`select#2`) NO_RANGE_OPTIMIZATION(`t3`@`select#1` `PRIMARY`) */ `test`.`t3` semi join (`test`.`t1` join `test`.`t2`) set `test`.`t3`.`f3` = 'mnbv' where `test`.`t1`.`f1` = `test`.`t3`.`f1` and `test`.`t2`.`f1` = `test`.`t3`.`f1` and `test`.`t2`.`f2` = `test`.`t3`.`f2` and `test`.`t3`.`f1` > 30 and `test`.`t3`.`f1` < 33 and `test`.`t3`.`f2` between `test`.`t3`.`f1` and `test`.`t1`.`f2` and `test`.`t3`.`f2` + 1 >= `test`.`t3`.`f1` + 1 and `test`.`t3`.`f3` = `test`.`t2`.`f3`
# Same as above but addressing tables with QB name
EXPLAIN EXTENDED
UPDATE /*+ NO_RANGE_OPTIMIZATION(t3 PRIMARY) BKA(t2@QB1) NO_BNL(t1@QB1)*/ t3
SET f3 = 'mnbv' WHERE f1 > 30 AND f1 < 33 AND (t3.f1, t3.f2, t3.f3) IN
(SELECT /*+ QB_NAME(QB1) */ t2.f1, t2.f2, t2.f3 FROM t1,t2 WHERE t1.f1=t2.f1 AND
t2.f2 BETWEEN t1.f1 AND t1.f2 AND t2.f2 + 1 >= t1.f1 + 1);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t3 range PRIMARY,f2_idx,f3_idx f2_idx 4 NULL 2 100.00 Using index condition; Using where
1 PRIMARY t1 ALL NULL NULL NULL NULL 3 3.33 Using where
1 PRIMARY t2 ref f1 f1 8 test.t3.f1,test.t3.f2 2 50.00 Using where; FirstMatch(t3)
Warnings:
Note 1003 update /*+ BKA(`t2`@`QB1`) NO_BNL(`t1`@`QB1`) NO_RANGE_OPTIMIZATION(`t3`@`select#1` `PRIMARY`) */ `test`.`t3` semi join (`test`.`t1` join `test`.`t2`) set `test`.`t3`.`f3` = 'mnbv' where `test`.`t1`.`f1` = `test`.`t3`.`f1` and `test`.`t2`.`f1` = `test`.`t3`.`f1` and `test`.`t2`.`f2` = `test`.`t3`.`f2` and `test`.`t3`.`f1` > 30 and `test`.`t3`.`f1` < 33 and `test`.`t3`.`f2` between `test`.`t3`.`f1` and `test`.`t1`.`f2` and `test`.`t3`.`f2` + 1 >= `test`.`t3`.`f1` + 1 and `test`.`t3`.`f3` = `test`.`t2`.`f3`
# Turn off range access for all keys.
EXPLAIN EXTENDED UPDATE /*+ NO_RANGE_OPTIMIZATION(t3) */ t3
SET f3 = 'mnbv' WHERE f1 > 30 AND f1 < 33 AND (t3.f1, t3.f2, t3.f3) IN
Expand All @@ -450,6 +462,31 @@ id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t3 eq_ref PRIMARY,f2_idx,f3_idx PRIMARY 4 test.t2.f1 1 100.00 Using where; End temporary
Warnings:
Note 1003 update /*+ NO_RANGE_OPTIMIZATION(`t3`@`select#1`) */ `test`.`t3` semi join (`test`.`t1` join `test`.`t2`) set `test`.`t3`.`f3` = 'mnbv' where `test`.`t1`.`f1` = `test`.`t2`.`f1` and `test`.`t3`.`f1` = `test`.`t2`.`f1` and `test`.`t3`.`f2` = `test`.`t2`.`f2` and `test`.`t2`.`f1` > 30 and `test`.`t2`.`f1` < 33 and `test`.`t2`.`f2` between `test`.`t2`.`f1` and `test`.`t1`.`f2` and `test`.`t2`.`f2` + 1 >= `test`.`t2`.`f1` + 1 and `test`.`t3`.`f3` = `test`.`t2`.`f3`
# Multi-table UPDATE with a derived table
EXPLAIN EXTENDED
UPDATE /*+ NO_RANGE_OPTIMIZATION(t2@dt)*/ t3,
(SELECT /*+ qb_name(dt)*/ t1.* FROM t1, t2 WHERE t1.f1 > t2.f1) AS dt
SET t3.f3 = 'mnbv' WHERE t3.f1 = dt.f1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t3 ALL PRIMARY,f2_idx NULL NULL NULL 56 100.00
1 PRIMARY <derived2> ref key0 key0 5 test.t3.f1 8 100.00
2 DERIVED t1 ALL NULL NULL NULL NULL 3 100.00
2 DERIVED t2 index f1 f1 8 NULL 28 100.00 Using where; Using index; Using join buffer (flat, BNL join)
Warnings:
Note 1003 /* select#1 */ update /*+ NO_RANGE_OPTIMIZATION(`t2`@`dt`) */ `test`.`t3` join (/* select#2 */ select /*+ QB_NAME(`dt`) */ `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` join `test`.`t2` where `test`.`t1`.`f1` > `test`.`t2`.`f1`) `dt` set `test`.`t3`.`f3` = 'mnbv' where `dt`.`f1` = `test`.`t3`.`f1`
# Multi-table UPDATE with a derived table and both table-level and
# query block-level hints
EXPLAIN EXTENDED
UPDATE /*+ NO_RANGE_OPTIMIZATION(t2@dt) NO_BNL(@dt)*/ t3,
(SELECT /*+ qb_name(dt)*/ t1.* FROM t1, t2 WHERE t1.f1 > t2.f1) AS dt
SET t3.f3 = 'mnbv' WHERE t3.f1 = dt.f1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t3 ALL PRIMARY,f2_idx NULL NULL NULL 56 100.00
1 PRIMARY <derived2> ref key0 key0 5 test.t3.f1 8 100.00
2 DERIVED t1 ALL NULL NULL NULL NULL 3 100.00
2 DERIVED t2 index f1 f1 8 NULL 28 100.00 Using where; Using index
Warnings:
Note 1003 /* select#1 */ update /*+ NO_BNL(@`dt`) NO_RANGE_OPTIMIZATION(`t2`@`dt`) */ `test`.`t3` join (/* select#2 */ select /*+ QB_NAME(`dt`) */ `test`.`t1`.`f1` AS `f1`,`test`.`t1`.`f2` AS `f2` from `test`.`t1` join `test`.`t2` where `test`.`t1`.`f1` > `test`.`t2`.`f1`) `dt` set `test`.`t3`.`f3` = 'mnbv' where `dt`.`f1` = `test`.`t3`.`f1`
EXPLAIN EXTENDED DELETE FROM t3
WHERE f1 > 30 AND f1 < 33 AND (t3.f1, t3.f2, t3.f3) IN
(SELECT /*+ QB_NAME(qb1) */ t2.f1, t2.f2, t2.f3 FROM t1,t2 WHERE t1.f1=t2.f1 AND
Expand Down Expand Up @@ -500,7 +537,7 @@ Warnings:
Note 1003 (insert into `test`.`t3`(f1,f2,f3) select /*+ NO_ICP(`t5`@`select#1`) */ `test`.`t4`.`x` AS `x`,`test`.`t5`.`y` AS `y`,'filler' AS `filler` from `test`.`t4` join `test`.`t4` `t5` where `test`.`t4`.`y` = 8 and `test`.`t5`.`x` between 7 and <cache>(8 + 0))
# Turn off ICP for a particular table and a key
EXPLAIN EXTENDED INSERT INTO t3(f1, f2, f3)
(SELECT /*+ QB_NAME(qb1) NO_ICP(t5@QB1 x_idx)*/ t4.x, t5.y, 'filler' FROM t4, t4 t5
(SELECT /*+ NO_ICP(t5@QB1 x_idx) QB_NAME(qb1) */ t4.x, t5.y, 'filler' FROM t4, t4 t5
WHERE t4.y = 8 AND t5.x BETWEEN 7 AND t4.y+0);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t4 ref y_idx y_idx 5 const 1 100.00
Expand Down Expand Up @@ -550,15 +587,14 @@ id select_type table type possible_keys key key_len ref rows filtered Extra
Warnings:
Warning 4219 Hint QB_NAME(`qb1`) is ignored as conflicting/duplicated
Note 1003 select /*+ QB_NAME(`qb1`) */ `test`.`t2`.`f1` AS `f1`,`test`.`t2`.`f2` AS `f2`,`test`.`t2`.`f3` AS `f3` from `test`.`t2`
# Should issue warning
EXPLAIN EXTENDED SELECT /*+ BKA(@qb1) QB_NAME(qb1) */ t2.f1, t2.f2, t2.f3 FROM t1,t2
# QB_NAME may appear after the hint, but the hint is still resolved
EXPLAIN EXTENDED SELECT /*+ NO_BNL(@qb1) QB_NAME(qb1) */ t2.f1, t2.f2, t2.f3 FROM t1,t2
WHERE t1.f1=t2.f1 AND t2.f2 BETWEEN t1.f1 and t1.f2 and t2.f2 + 1 >= t1.f1 + 1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 3 100.00
1 SIMPLE t2 ALL f1 NULL NULL NULL 28 25.00 Using where; Using join buffer (flat, BNL join)
1 SIMPLE t2 ALL f1 NULL NULL NULL 28 25.00 Using where
Warnings:
Warning 4220 Query block name `qb1` is not found for BKA hint
Note 1003 select /*+ QB_NAME(`qb1`) */ `test`.`t2`.`f1` AS `f1`,`test`.`t2`.`f2` AS `f2`,`test`.`t2`.`f3` AS `f3` from `test`.`t1` join `test`.`t2` where `test`.`t2`.`f1` = `test`.`t1`.`f1` and `test`.`t2`.`f2` between `test`.`t1`.`f1` and `test`.`t1`.`f2` and `test`.`t2`.`f2` + 1 >= `test`.`t1`.`f1` + 1
Note 1003 select /*+ QB_NAME(`qb1`) NO_BNL(@`qb1`) */ `test`.`t2`.`f1` AS `f1`,`test`.`t2`.`f2` AS `f2`,`test`.`t2`.`f3` AS `f3` from `test`.`t1` join `test`.`t2` where `test`.`t2`.`f1` = `test`.`t1`.`f1` and `test`.`t2`.`f2` between `test`.`t1`.`f1` and `test`.`t1`.`f2` and `test`.`t2`.`f2` + 1 >= `test`.`t1`.`f1` + 1
# Should not crash
PREPARE stmt1 FROM "SELECT /*+ BKA(t2) */ t2.f1, t2.f2, t2.f3 FROM t1,t2
WHERE t1.f1=t2.f1 AND t2.f2 BETWEEN t1.f1 and t1.f2 and t2.f2 + 1 >= t1.f1 + 1";
Expand Down
26 changes: 23 additions & 3 deletions mysql-test/main/opt_hints.test
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Original file line number Diff line number Diff line change
Expand Up @@ -248,12 +248,32 @@ SET f3 = 'mnbv' WHERE f1 > 30 AND f1 < 33 AND (t3.f1, t3.f2, t3.f3) IN
(SELECT /*+ BKA(t2) NO_BNL(t1) */ t2.f1, t2.f2, t2.f3 FROM t1,t2 WHERE t1.f1=t2.f1 AND
t2.f2 BETWEEN t1.f1 AND t1.f2 AND t2.f2 + 1 >= t1.f1 + 1);

--echo # Same as above but addressing tables with QB name
EXPLAIN EXTENDED
UPDATE /*+ NO_RANGE_OPTIMIZATION(t3 PRIMARY) BKA(t2@QB1) NO_BNL(t1@QB1)*/ t3
SET f3 = 'mnbv' WHERE f1 > 30 AND f1 < 33 AND (t3.f1, t3.f2, t3.f3) IN
(SELECT /*+ QB_NAME(QB1) */ t2.f1, t2.f2, t2.f3 FROM t1,t2 WHERE t1.f1=t2.f1 AND
t2.f2 BETWEEN t1.f1 AND t1.f2 AND t2.f2 + 1 >= t1.f1 + 1);

--echo # Turn off range access for all keys.
EXPLAIN EXTENDED UPDATE /*+ NO_RANGE_OPTIMIZATION(t3) */ t3
SET f3 = 'mnbv' WHERE f1 > 30 AND f1 < 33 AND (t3.f1, t3.f2, t3.f3) IN
(SELECT t2.f1, t2.f2, t2.f3 FROM t1,t2 WHERE t1.f1=t2.f1 AND
t2.f2 BETWEEN t1.f1 AND t1.f2 AND t2.f2 + 1 >= t1.f1 + 1);

--echo # Multi-table UPDATE with a derived table
EXPLAIN EXTENDED
UPDATE /*+ NO_RANGE_OPTIMIZATION(t2@dt)*/ t3,
(SELECT /*+ qb_name(dt)*/ t1.* FROM t1, t2 WHERE t1.f1 > t2.f1) AS dt
SET t3.f3 = 'mnbv' WHERE t3.f1 = dt.f1;

--echo # Multi-table UPDATE with a derived table and both table-level and
--echo # query block-level hints
EXPLAIN EXTENDED
UPDATE /*+ NO_RANGE_OPTIMIZATION(t2@dt) NO_BNL(@dt)*/ t3,
(SELECT /*+ qb_name(dt)*/ t1.* FROM t1, t2 WHERE t1.f1 > t2.f1) AS dt
SET t3.f3 = 'mnbv' WHERE t3.f1 = dt.f1;

EXPLAIN EXTENDED DELETE FROM t3
WHERE f1 > 30 AND f1 < 33 AND (t3.f1, t3.f2, t3.f3) IN
(SELECT /*+ QB_NAME(qb1) */ t2.f1, t2.f2, t2.f3 FROM t1,t2 WHERE t1.f1=t2.f1 AND
Expand Down Expand Up @@ -282,7 +302,7 @@ EXPLAIN EXTENDED INSERT INTO t3(f1, f2, f3)

--echo # Turn off ICP for a particular table and a key
EXPLAIN EXTENDED INSERT INTO t3(f1, f2, f3)
(SELECT /*+ QB_NAME(qb1) NO_ICP(t5@QB1 x_idx)*/ t4.x, t5.y, 'filler' FROM t4, t4 t5
(SELECT /*+ NO_ICP(t5@QB1 x_idx) QB_NAME(qb1) */ t4.x, t5.y, 'filler' FROM t4, t4 t5
WHERE t4.y = 8 AND t5.x BETWEEN 7 AND t4.y+0);

--echo # Make sure ICP is expected to be used when there are no hints
Expand All @@ -308,8 +328,8 @@ EXPLAIN EXTENDED REPLACE INTO t3(f1, f2, f3)

--echo # Should issue warning
EXPLAIN EXTENDED SELECT /*+ QB_NAME(qb1) QB_NAME(qb1 ) */ * FROM t2;
--echo # Should issue warning
EXPLAIN EXTENDED SELECT /*+ BKA(@qb1) QB_NAME(qb1) */ t2.f1, t2.f2, t2.f3 FROM t1,t2
--echo # QB_NAME may appear after the hint, but the hint is still resolved
EXPLAIN EXTENDED SELECT /*+ NO_BNL(@qb1) QB_NAME(qb1) */ t2.f1, t2.f2, t2.f3 FROM t1,t2
WHERE t1.f1=t2.f1 AND t2.f2 BETWEEN t1.f1 and t1.f2 and t2.f2 + 1 >= t1.f1 + 1;

--echo # Should not crash
Expand Down
177 changes: 177 additions & 0 deletions mysql-test/main/opt_hints_impl_qb_name.inc
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Original file line number Diff line number Diff line change
@@ -0,0 +1,177 @@
--echo # Table-level hint
explain extended select /*+ no_bnl(t2@dt)*/ * from
(select t1.* from t1, t2 where t1.a > t2.a) as dt;

--echo # QB-level hint
explain extended select /*+ no_bnl(@dt)*/ * from
(select t1.* from t1, t2 where t1.a > t2.a) as dt;

--echo # Index-level hints
--echo # Without the hint 'range' index access would be chosen
explain extended select /*+ no_index(t1@`T`)*/ * from
(select * from t1 where a < 3) t;

--echo # Without the hint 'range' index access would be chosen
explain extended select /*+ no_range_optimization(t1@t1)*/ * from
(select * from t1 where a > 100 and a < 120) as t1;

--echo # Regular and derived tables share same name but the hint is applied correctly
explain extended select /*+ index(t1@t1 idx_ab)*/ * from
(select * from t1 where a < 3) as t1;

explain extended select /*+ no_index(t1@t2 idx_a) index(t1@t1 idx_ab)*/ * from
(select * from t1 where a < 3) as t1, (select * from t1 where a < 5) as t2;

explain extended select /*+ no_index(t1@t1 idx_a, idx_ab)*/ * from
(select * from t1 where a < 3) as t1, (select * from t1 where a < 5) as t2;

--echo # Nested derived tables
explain extended select /*+ no_bnl(t1@dt2)*/ * from
(select count(*) from t1, (select * from t1 where a < 5) dt1) as dt2;

explain extended select /*+ no_index(t1@DT2)*/ * from
(select count(*) from t1, (select * from t1 where a < 5) dt1) as dt2;

--echo # Explicit QB name overrides the implicit one
explain extended select /*+ no_index(t1@dt2)*/ * from
(select count(*) from t1, (select /*+ qb_name(dt2)*/ * from t1 where a < 5) dt1) as dt2;

--echo # Both hints are applied
explain extended select /*+ no_index(t1@dt1) no_bnl(t1@dt2)*/ * from
(select count(*) from t1, (select * from t1 where a < 5) dt1) as dt2;

--echo # Nested derived tables with ambiguous names
explain extended select * from
(select count(*) from t1, (select * from t1 where a < 5) t1) as t1;

--echo # Warning on ambiguous query block name, hint is ignored

--disable_ps_protocol
# PS protocol is disabled because the warning is genererated only during
# PREPARE step of a statement. When the QB name cannot be resolved the hint
# is discarded, so it is not present during EXECUTE step. The same applies
# not only to implicit but also to explicit QB names.

explain extended select /*+ no_index(t1@t1)*/* from
(select count(*) from t1, (select * from t1 where a < 5) t1) as t1;

--echo # The hint cannot be applied to a derived table with UNION
explain extended select /*+ no_index(t2@t1)*/* from
(select * from t1 where a < 3 union select * from t2 where a < 9) as t1;

explain extended select /*+ no_index(t1@t1)*/* from
(select * from t1 where a < 3 union select * from t2 where a < 9) as t1;

--echo # Test INSERT..SELECT
explain extended insert into t2 select /*+ no_bnl(t2@dt)*/ * from
(select t1.* from t1, t2 where t1.a > t2.a) as dt;

--echo # MERGE/NO_MERGE hints are resolved early and so do not support
--echo # implicit QB names. Warning is expected
explain extended select /*+ no_merge(@dt)*/ * from
(select * from (select t1.* from t1, t2 where t1.a > t2.a) as dt1) as dt;

--enable_ps_protocol

--echo # ======================================
--echo # Test CTEs
--echo # By default BNL and index access to t1 is used.
explain extended
with cte as (select count(*) from t1, (select * from t1 where a < 5) dt1)
select * from cte;

explain extended
with cte as (select count(*) from t1, (select * from t1 where a < 5) dt1)
select /*+ no_bnl(t1@cte)*/ * from cte;

explain extended
with cte as (select count(*) from t1, (select * from t1 where a < 5) dt1)
select /*+ no_bnl(@cte)*/ * from cte;

explain extended
with cte as (select count(*) from t1, (select * from t1 where a < 5) dt1)
select /*+ no_index(t1@cte)*/ * from cte;

explain extended
with cte as (select count(*) from t1, (select * from t1 where a < 5) dt1)
select /*+ no_index(t1@cte) no_index(t1@dt1)*/ * from cte;

explain extended
with cte as (select count(*) from t1, (select * from t1 where a < 5) dt1)
select /*+ no_index(t1@dt1 idx_a) no_bnl(@cte)*/ * from cte;

--echo # Ambiguity: multiple occurencies of `cte`, the hint is ignored

--disable_ps_protocol
# See the comment above for why PS protocol is disabled

explain extended
with cte as (select count(*) as cnt from t1, (select * from t1 where a < 5) dt1)
select /*+ no_bnl(@cte)*/ * from cte where cnt > 10
union
select * from cte where cnt < 100;

--echo # However, if CTE occurencies have different aliases, the hint can be applied
explain extended
with cte as (select count(*) as cnt from t1, (select * from t1 where a < 5) dt1)
select /*+ no_index(t1@cte1)*/ * from cte as cte1 where cnt > 10
union
select * from cte where cnt < 100;

--enable_ps_protocol

--echo # ======================================
--echo # Test views
create view v1 as select * from t1 where a < 100;

--echo # Default execution plan
explain extended select *
from v1, v1 as v2 where v1.a = v2.a and v1.a < 3;

explain extended
select /*+ index(t1@`v1` idx_ab) no_index(t1@`v2`)*/ *
from v1, v1 as v2 where v1.a = v2.a and v1.a < 3;

--echo # Nested views
create view v2 as select * from v1 where a < 300;

--echo # Default execution plan
explain extended select * from v2;

--echo # Addressing an object inside a nested view
explain extended select /*+ index(t1@`v1` idx_ab)*/ * from v2;

create view v3 as select * from t1 union select * from t2;

--echo # Unable to apply the hint to a table with UNION

--disable_ps_protocol
# See the comment above for why PS protocol is disabled

explain extended select /*+ no_index(t1@v3) */ * from v3;

--echo # Ambiguity: view `v1` appears two times - should warn and ignore hint
explain extended select /*+ index(t2@v1) */ * from v1,
(select a from v1 where b > 5) dt;

--enable_ps_protocol

--echo # Implicit QB names are not supported inside views
create view v4 as select /*+ no_bnl(t2@dt)*/ * from
(select t1.* from t1, t2 where t1.a > t2.a) as dt;

show create view v4;

--echo # However, a derived table inside a view can be addressed from outer query
create view v5 as select dt.a from
t1, (select t1.* from t1, t2 where t1.a > t2.a) as dt where t1.a=dt.a;

--echo # Addressing a single table
explain extended select /*+ no_bnl(t2@dt) */* from v5;
--echo # Addressing the whole derived table
explain extended select /*+ no_bnl(@dt) */* from v5;

--echo # Derived tables inside views can be addressed by their aliases
explain extended select /*+ no_bnl(t2@dt) */ * from v4;

drop view v1, v2, v3, v4, v5;
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