MDEV-33281 Fix code review comments

mysql-test/main/lowercase_table.result

@@ -208,3 +208,30 @@ DROP PACKAGE test.pkg;
 #
 # End of 11.4 tests
 #
+#
+# Start of 11.7 tests
+#
+#
+# MDEV-33281 Implement optimizer hints like in MySQL
+#
+SET NAMES utf8mb4;
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1), (2);
+SELECT /*+BKA(a) BKA(å)*/ a.a FROM t1 a, t1 å;
+a
+1
+2
+1
+2
+SELECT a.a, A.a FROM t1 a, t1 A;
+ERROR 42000: Not unique table/alias: 'A'
+SELECT /*+BKA(a) BKA(A)*/ a.a FROM t1 a;
+a
+1
+2
+Warnings:
+Warning	4202	Hint BKA("A") is ignored as conflicting/duplicated
+DROP TABLE t1;
+#
+# End of 11.7 tests
+#

mysql-test/main/lowercase_table.test

@@ -205,3 +205,33 @@ DROP PACKAGE test.pkg;
 --echo #
 --echo # End of 11.4 tests
 --echo #
+
+
+--echo #
+--echo # Start of 11.7 tests
+--echo #
+
+--echo #
+--echo # MDEV-33281 Implement optimizer hints like in MySQL
+--echo #
+
+SET NAMES utf8mb4;
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1), (2);
+
+# Test that aliases are accent sensitive with lowercase-table-names=1
+# Test that table names in hints are also accent sensitive
+SELECT /*+BKA(a) BKA(å)*/ a.a FROM t1 a, t1 å;
+
+# Test that aliases are case insensitive with lowercase-table-names=1
+--error ER_NONUNIQ_TABLE
+SELECT a.a, A.a FROM t1 a, t1 A;
+# Test that table names in hints are also case insensitive
+SELECT /*+BKA(a) BKA(A)*/ a.a FROM t1 a;
+
+DROP TABLE t1;
+
+--echo #
+--echo # End of 11.7 tests
+--echo #

mysql-test/main/lowercase_table5.result

@@ -189,3 +189,28 @@ DROP DATABASE MYSQL;
 #
 # End of 10.5 tests
 #
+#
+# Start of 11.7 tests
+#
+#
+# MDEV-33281 Implement optimizer hints like in MySQL
+#
+SET NAMES utf8mb4;
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1), (2);
+SELECT /*+BKA(a) BKA(å)*/ a.a, å.a FROM t1 a, t1 å;
+a	a
+1	1
+2	1
+1	2
+2	2
+SELECT /*+BKA(a) BKA(A)*/ a.a, A.a FROM t1 a, t1 A;
+a	a
+1	1
+2	1
+1	2
+2	2
+DROP TABLE t1;
+#
+# End of 11.7 tests
+#

mysql-test/main/lowercase_table5.test

@@ -187,3 +187,30 @@ DROP DATABASE MYSQL;
 --echo #
 --echo # End of 10.5 tests
 --echo #
+
+--echo #
+--echo # Start of 11.7 tests
+--echo #
+
+--echo #
+--echo # MDEV-33281 Implement optimizer hints like in MySQL
+--echo #
+
+SET NAMES utf8mb4;
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1), (2);
+
+# Test that table aliases are accent sensitive with lowercase-table-names=0
+# Test that table names in hints are also accent sensitive
+SELECT /*+BKA(a) BKA(å)*/ a.a, å.a FROM t1 a, t1 å;
+
+# Test that table aliases are case sensitive with lowercase-table-names=0
+# Test that table names in hints are also case sensitive
+SELECT /*+BKA(a) BKA(A)*/ a.a, A.a FROM t1 a, t1 A;
+
+DROP TABLE t1;
+
+--echo #
+--echo # End of 11.7 tests
+--echo #

mysql-test/main/opt_hints.test

---echo # WL#8017 Infrastructure for Optimizer Hints
 --enable_prepare_warnings
 
+SET NAMES utf8mb4;
+
+--echo # Testing that index names in hints are accent sensitive case insensitive
+CREATE TABLE t1 (a INT, ä INT, INDEX idx_a(a), INDEX idx_ä(ä));
+INSERT INTO t1 VALUES (1,1),(2,2);
+SELECT /*+ NO_MRR(t1 idx_a) */ a FROM t1;
+SELECT /*+ NO_MRR(t1 idx_A) */ a FROM t1;
+SELECT /*+ NO_MRR(t1 idx_å) */ a FROM t1;
+SELECT /*+ NO_MRR(t1 idx_a, idx_å, idx_A) */ a FROM t1;
+DROP TABLE t1;
+
+--echo # Testing that query block names are accent sensitive case insensitive
+CREATE TABLE t1 (a INT);
+SELECT /*+ QB_NAME(a) BKA(t1@a) BKA(t1@A) */ * FROM t1;
+SELECT /*+ QB_NAME(a) BKA(t1@a) BKA(t1@å) */ * FROM t1;
+DROP TABLE t1;
+
 CREATE TABLE t1(f1 INT, f2 INT);
 INSERT INTO t1 VALUES
 (1,1),(2,2),(3,3);
@@ -31,7 +47,6 @@ ANALYZE TABLE t1;
 ANALYZE TABLE t2;
 ANALYZE TABLE t3;
 
-
 --echo # NO_RANGE_OPTIMIZATION hint testing
 set optimizer_switch=default;
 
@@ -50,16 +65,44 @@ SHOW STATUS LIKE 'handler_read%';
 EXPLAIN EXTENDED SELECT f1 FROM t3 WHERE f1 > 30 AND f1 < 33;
 --echo # Turn off range access for PRIMARY key
 --echo # Should use range access by f2_idx key
-EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(t3 PRIMARY) */ f1 FROM t3 WHERE f1 > 30 AND f1 < 33;
+EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(t3 PRIMARY) */ f1
+  FROM t3 WHERE f1 > 30 AND f1 < 33;
 --echo # Turn off range access for PRIMARY & f2_idx keys
 --echo # Should use index access
-EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(t3 PRIMARY, f2_idx) */ f1 FROM t3 WHERE f1 > 30 AND f1 < 33;
+EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(t3 PRIMARY, f2_idx) */ f1
+  FROM t3 WHERE f1 > 30 AND f1 < 33;
 --echo # Turn off range access for all keys
 --echo # Should use index access
-EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(t3) */ f1 FROM t3 WHERE f1 > 30 AND f1 < 33;
+EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(t3) */ f1
+  FROM t3 WHERE f1 > 30 AND f1 < 33;
 --echo # Turn off range access for PRIMARY & f2_idx keys
 --echo # Should use index access
-EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(t3 PRIMARY) NO_RANGE_OPTIMIZATION(t3 f2_idx) */ f1 FROM t3 WHERE f1 > 30 AND f1 < 33;
+EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(t3 PRIMARY) NO_RANGE_OPTIMIZATION(t3 f2_idx) */ f1
+  FROM t3 WHERE f1 > 30 AND f1 < 33;
+
+--echo # Create a clone of t3 with cyrillic names
+CREATE TABLE таблица (f1 INT NOT NULL, поле2 INT, поле3 VARCHAR(32),
+                 PRIMARY KEY(f1), KEY f2_индекс(f1), KEY f3_индекс(поле3))
+                 AS SELECT * FROM t3;
+ANALYZE TABLE таблица;
+--echo # Turn off range access for PRIMARY key
+--echo # Should use range access by f2_индекс key
+EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(таблица PRIMARY) */ f1
+  FROM таблица WHERE f1 > 30 AND f1 < 33;
+--echo # Turn off range access for PRIMARY & f2_индекс keys
+--echo # Should use index access
+EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(таблица PRIMARY, f2_индекс) */ f1
+  FROM таблица WHERE f1 > 30 AND f1 < 33;
+--echo # Turn off range access for all keys
+--echo # Should use index access
+EXPLAIN EXTENDED SELECT /*+ NO_RANGE_OPTIMIZATION(таблица) */ f1
+  FROM таблица WHERE f1 > 30 AND f1 < 33;
+--echo # Turn off range access for PRIMARY & f2_индекс keys
+--echo # Should use index access
+EXPLAIN EXTENDED
+  SELECT /*+ NO_RANGE_OPTIMIZATION(таблица PRIMARY) NO_RANGE_OPTIMIZATION(таблица f2_индекс) */ f1
+  FROM таблица WHERE f1 > 30 AND f1 < 33;
+DROP TABLE таблица;
 
 --echo # NO_ICP hint testing
 set optimizer_switch='index_condition_pushdown=on';
@@ -79,6 +122,12 @@ EXPLAIN EXTENDED SELECT /*+ NO_ICP(t5@qb1 x_idx) */ * FROM
   (SELECT /*+ QB_NAME(QB1) */ t4.x, t5.y FROM t4, t4 t5
    WHERE t4.y = 8 AND t5.x BETWEEN 7 AND t4.y+0) AS TD;
 
+--echo # Cyrillic query block name
+EXPLAIN EXTENDED SELECT /*+ NO_ICP(t5@блок1 x_idx) */ * FROM
+  (SELECT /*+ QB_NAME(блок1) */ t4.x, t5.y FROM t4, t4 t5
+   WHERE t4.y = 8 AND t5.x BETWEEN 7 AND t4.y+0) AS TD;
+
+
 --echo # Expected warning for z_idx key, unresolved name.
 EXPLAIN EXTENDED SELECT * FROM
   (SELECT /*+ NO_ICP(t5 y_idx, x_idx, z_idx) */ t4.x, t5.y FROM t4, t4 t5
@@ -157,7 +206,7 @@ EXPLAIN EXTENDED SELECT /*+ NO_BKA(t12) */ * FROM t12, t13
 EXPLAIN EXTENDED SELECT /*+ QB_NAME(QB1) NO_BKA(t13@QB1) */ * FROM t12, t13 
   WHERE t12.a=t13.a AND (t13.b+1 <= t13.b+1);
 
---echo # UPDATE|DELETE|INSERT hint testing
+--echo # UPDATE|DELETE|INSERT|REPLACE hint testing
 EXPLAIN EXTENDED UPDATE 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
@@ -207,6 +256,25 @@ EXPLAIN EXTENDED INSERT /*+ NO_ICP(t5@QB1 x_idx) */ INTO t3(f1, f2, f3)
   (SELECT /*+ 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
+EXPLAIN EXTENDED REPLACE INTO t3(f1, f2, f3)
+  (SELECT t4.x, t5.y, 'filler' FROM t4, t4 t5 WHERE t4.y = 8 AND t5.x BETWEEN 7 AND t4.y+0);
+
+--echo # Turn off ICP. ICP should not be used.
+EXPLAIN EXTENDED REPLACE INTO t3(f1, f2, f3)
+  (SELECT /*+ NO_ICP(t5) */t4.x, t5.y, 'filler' FROM t4, t4 t5
+   WHERE t4.y = 8 AND t5.x BETWEEN 7 AND t4.y+0);
+
+--echo # Turn off ICP for a particular table
+EXPLAIN EXTENDED REPLACE /*+ NO_ICP(t5@QB1) */ INTO t3(f1, f2, f3)
+  (SELECT /*+ 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 # Turn off ICP for a particular table and a key
+EXPLAIN EXTENDED REPLACE /*+ NO_ICP(t5@QB1 x_idx) */ INTO t3(f1, f2, f3)
+  (SELECT /*+ 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 # Misc tests
 
 --echo # Should issue warning
@@ -475,7 +543,6 @@ SELECT  /*+ NO_ICP (  ) */ 1;
 SELECT  /*+ NO_ICP() */ 1 UNION SELECT 1;
 (SELECT /*+ NO_ICP() */ 1) UNION (SELECT 1);
 
---echo # OLEGS: this one does not issue a warning although should:
 ((SELECT  /* + NO_ICP() */ 1));
 
 UPDATE  /*+ NO_ICP() */ t1 SET i = 10;

mysql-test/suite/gcol/inc/gcol_select.inc

@@ -895,7 +895,7 @@ CREATE TABLE t (
 
 INSERT INTO t(a,b) VALUES(1,'cccc');
 let $query=
-SELECT /*+ bka() */ 1 AS c FROM t AS b RIGHT JOIN t AS c ON b.a > c.c
+SELECT 1 AS c FROM t AS b RIGHT JOIN t AS c ON b.a > c.c
 WHERE b.b>c.a;
 eval EXPLAIN $query;
 eval $query;
@@ -1022,13 +1022,12 @@ VALUES (1, 'j'), (2, 'c'), (0, 'a');
 
 ANALYZE TABLE t1, t2, t3, t4;
 
-# Hint is added to avoid materialization of the subquery
 let query=
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
   (
-    SELECT /*+ QB_NAME(subq1) */ t4.i1
+    SELECT t4.i1
     FROM t4
     WHERE t4.c1 < 'o'
   )
@@ -1049,13 +1048,12 @@ if ($support_virtual_index)
 ALTER TABLE t3 ADD INDEX v_idx2 (i2_key, i1);
 }
 
-# Hint is added to avoid materialization of the subquery
 let query=
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
   (
-    SELECT /*+ QB_NAME(subq1) */ t4.i1
+    SELECT t4.i1
     FROM t4
     WHERE t4.c1 < 'o'
   )
@@ -1079,11 +1077,11 @@ ALTER TABLE t3 DROP INDEX v_idx;
 
 # Hint is added to avoid materialization of the subquery
 let query=
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
   (
-    SELECT /*+ QB_NAME(subq1) */ t4.i1
+    SELECT t4.i1
     FROM t4
     WHERE t4.c1 < 'o'
   )
@@ -1117,11 +1115,11 @@ VALUES (10,1), (11,1), (12,1), (13,1), (14,1),(15,1), (16,1),(17,1), (18,1),
 --echo # non-covering.
 # Hint is added to avoid materialization of the subquery
 let query=
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1, t3.i1
+SELECT t1.c1, t2.i1, t3.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
   (
-    SELECT /*+ QB_NAME(subq1) */ t4.i1
+    SELECT t4.i1
     FROM t4
     WHERE t4.c1 < 'o'
   )
@@ -1154,11 +1152,11 @@ eval $query;
 # an extra query condition is added to the subquery.
 # Hint is added to avoid materialization of the subquery
 let query=
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
   (
-    SELECT /*+ QB_NAME(subq1) */ t4.i1
+    SELECT t4.i1
     FROM t4
     WHERE t4.c1 < 'o' and t4.i1 < (t2.i1 + 1)
   )

mysql-test/suite/gcol/r/gcol_bugfixes.result

@@ -444,7 +444,7 @@ Note	1265	Data truncated for column 'c13' at row 1
 Note	1265	Data truncated for column 'c11' at row 2
 Note	1265	Data truncated for column 'c13' at row 2
 CREATE VIEW view_C AS SELECT * FROM C;
-SELECT /*+ NO_BNL(t1) */ t1.c13 FROM C AS t2 STRAIGHT_JOIN C AS t1 FORCE INDEX(c13);
+SELECT t1.c13 FROM C AS t2 STRAIGHT_JOIN C AS t1 FORCE INDEX(c13);
 c13
 00:00:00
 00:00:00

mysql-test/suite/gcol/r/gcol_select_innodb.result

@@ -555,12 +555,12 @@ c BLOB GENERATED ALWAYS AS (a+b) VIRTUAL,
 UNIQUE KEY i0008 (a)
 );
 INSERT INTO t(a,b) VALUES(1,'cccc');
-EXPLAIN SELECT /*+ bka() */ 1 AS c FROM t AS b RIGHT JOIN t AS c ON b.a > c.c
+EXPLAIN SELECT 1 AS c FROM t AS b RIGHT JOIN t AS c ON b.a > c.c
 WHERE b.b>c.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	b	ALL	i0008	NULL	NULL	NULL	1	
 1	SIMPLE	c	ALL	i0008	NULL	NULL	NULL	1	Range checked for each record (index map: 0x1)
-SELECT /*+ bka() */ 1 AS c FROM t AS b RIGHT JOIN t AS c ON b.a > c.c
+SELECT 1 AS c FROM t AS b RIGHT JOIN t AS c ON b.a > c.c
 WHERE b.b>c.a;
 c
 Warnings:
@@ -689,11 +689,11 @@ test.t3	analyze	status	Engine-independent statistics collected
 test.t3	analyze	status	OK
 test.t4	analyze	status	Engine-independent statistics collected
 test.t4	analyze	status	OK
-EXPLAIN SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+EXPLAIN SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -704,11 +704,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t4.i1	1	Using where; End temporary
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -743,11 +743,11 @@ t	9
 #
 # Test 2: Two alternative covering indexes for the range scan
 #
-EXPLAIN SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+EXPLAIN SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -758,11 +758,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t4.i1	1	Using where; End temporary
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -798,11 +798,11 @@ t	9
 # Test 3: One covering index including the base column for the virtual
 #         column
 #
-EXPLAIN SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+EXPLAIN SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -813,11 +813,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t4.i1	1	Using where; End temporary
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -861,11 +861,11 @@ VALUES (10,1), (11,1), (12,1), (13,1), (14,1),(15,1), (16,1),(17,1), (18,1),
 (28,1), (29,1);
 # Change the query to read an extra column (t3.i1) making the index
 # non-covering.
-EXPLAIN SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1, t3.i1
+EXPLAIN SELECT t1.c1, t2.i1, t3.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -876,11 +876,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t4.i1	1	Using where; End temporary
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1, t3.i1
+SELECT t1.c1, t2.i1, t3.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -916,11 +916,11 @@ t	9	48
 # Test 5: Test where the added primary key to secondary indexes is
 #         used after it has been included in the join buffer
 #
-EXPLAIN SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+EXPLAIN SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o' and t4.i1 < (t2.i1 + 1)
 )
@@ -931,11 +931,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t4.i1	1	Using where
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	Using where; End temporary; Using join buffer (flat, BNL join)
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o' and t4.i1 < (t2.i1 + 1)
 )

mysql-test/suite/gcol/r/gcol_select_myisam.result

@@ -1174,14 +1174,14 @@ c BLOB GENERATED ALWAYS AS (a+b) VIRTUAL,
 UNIQUE KEY i0008 (a)
 );
 INSERT INTO t(a,b) VALUES(1,'cccc');
-EXPLAIN SELECT /*+ bka() */ 1 AS c FROM t AS b RIGHT JOIN t AS c ON b.a > c.c
+EXPLAIN SELECT 1 AS c FROM t AS b RIGHT JOIN t AS c ON b.a > c.c
 WHERE b.b>c.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 Warnings:
 Warning	1292	Truncated incorrect DOUBLE value: 'cccc'
 Warning	1292	Truncated incorrect DECIMAL value: 'cccc'
-SELECT /*+ bka() */ 1 AS c FROM t AS b RIGHT JOIN t AS c ON b.a > c.c
+SELECT 1 AS c FROM t AS b RIGHT JOIN t AS c ON b.a > c.c
 WHERE b.b>c.a;
 c
 Warnings:
@@ -1315,11 +1315,11 @@ test.t3	analyze	status	Engine-independent statistics collected
 test.t3	analyze	status	OK
 test.t4	analyze	status	Engine-independent statistics collected
 test.t4	analyze	status	OK
-EXPLAIN SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+EXPLAIN SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -1330,11 +1330,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY,v_idx	PRIMARY	4	test.t4.i1	1	Using where; End temporary
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -1370,11 +1370,11 @@ t	9
 # Test 2: Two alternative covering indexes for the range scan
 #
 ALTER TABLE t3 ADD INDEX v_idx2 (i2_key, i1);
-EXPLAIN SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+EXPLAIN SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -1385,11 +1385,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY,v_idx,v_idx2	PRIMARY	4	test.t4.i1	1	Using where; End temporary
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -1427,11 +1427,11 @@ t	9
 #
 # Drop the index with only the virtual column
 ALTER TABLE t3 DROP INDEX v_idx;
-EXPLAIN SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+EXPLAIN SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -1442,11 +1442,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY,v_idx2	PRIMARY	4	test.t4.i1	1	Using where; End temporary
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -1493,11 +1493,11 @@ VALUES (10,1), (11,1), (12,1), (13,1), (14,1),(15,1), (16,1),(17,1), (18,1),
 (28,1), (29,1);
 # Change the query to read an extra column (t3.i1) making the index
 # non-covering.
-EXPLAIN SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1, t3.i1
+EXPLAIN SELECT t1.c1, t2.i1, t3.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -1508,11 +1508,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY,v_idx	PRIMARY	4	test.t4.i1	1	Using where; End temporary
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	Using join buffer (flat, BNL join)
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1, t3.i1
+SELECT t1.c1, t2.i1, t3.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o'
   )
@@ -1548,11 +1548,11 @@ t	9	48
 # Test 5: Test where the added primary key to secondary indexes is
 #         used after it has been included in the join buffer
 #
-EXPLAIN SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+EXPLAIN SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o' and t4.i1 < (t2.i1 + 1)
 )
@@ -1563,11 +1563,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY,v_idx	PRIMARY	4	test.t4.i1	1	Using where
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	5	Using where; End temporary; Using join buffer (flat, BNL join)
-SELECT /*+ NO_SEMIJOIN(@subq1) */ t1.c1, t2.i1
+SELECT t1.c1, t2.i1
 FROM t1 STRAIGHT_JOIN t3 STRAIGHT_JOIN t2
 WHERE ( t3.pk IN
 (
-SELECT /*+ QB_NAME(subq1) */ t4.i1
+SELECT t4.i1
 FROM t4
 WHERE t4.c1 < 'o' and t4.i1 < (t2.i1 + 1)
 )

mysql-test/suite/gcol/t/gcol_bugfixes.test

@@ -429,7 +429,7 @@ INSERT INTO C (c8,c9) VALUES('1970-01-01',0),('1970-01-01',1);
 
 CREATE VIEW view_C AS SELECT * FROM C;
 
-SELECT /*+ NO_BNL(t1) */ t1.c13 FROM C AS t2 STRAIGHT_JOIN C AS t1 FORCE INDEX(c13);
+SELECT t1.c13 FROM C AS t2 STRAIGHT_JOIN C AS t1 FORCE INDEX(c13);
 SELECT DISTINCT t1.c13 FROM C AS t1, view_C AS t2;
 
 DROP TABLE C;

mysql-test/suite/json/r/json_table_mysql.result

@@ -469,7 +469,7 @@ id	jid	val
 2	1	2
 2	2	4
 2	3	6
-SELECT /*+ JOIN_ORDER(jt, t1) */ id, jt.*
+SELECT id, jt.*
 FROM t1,
 JSON_TABLE(jd, '$[*]' COLUMNS (jid FOR ORDINALITY,
 val INT PATH '$')) AS jt;
@@ -480,14 +480,14 @@ id	jid	val
 2	1	2
 2	2	4
 2	3	6
-EXPLAIN SELECT /*+ JOIN_ORDER(jt, t1) */ id, jt.*
+EXPLAIN SELECT id, jt.*
 FROM t1,
 JSON_TABLE(jd, '$[*]' COLUMNS (jid FOR ORDINALITY,
 val INT PATH '$')) AS jt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	
 1	SIMPLE	jt	ALL	NULL	NULL	NULL	NULL	40	Table function: json_table
-SELECT /*+ JOIN_ORDER(t2,jt) */ t1.id, t2.id, jt.*
+SELECT t1.id, t2.id, jt.*
 FROM t1,
 JSON_TABLE(t1.jd, '$[*]' COLUMNS (jid FOR ORDINALITY,
 val INT PATH '$')) AS jt,
@@ -514,7 +514,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
 1	SIMPLE	jt	ALL	NULL	NULL	NULL	NULL	40	Table function: json_table
-EXPLAIN SELECT /*+ JOIN_ORDER(t2,jt) */ t1.id, t2.id, jt.*
+EXPLAIN SELECT t1.id, t2.id, jt.*
 FROM t1,
 JSON_TABLE(t1.jd, '$[*]' COLUMNS (jid FOR ORDINALITY,
 val INT PATH '$')) AS jt,

mysql-test/suite/json/t/json_table_mysql.test

@@ -379,18 +379,18 @@ INSERT INTO t1 values (1, '[1,3,5]'),(2,'[2,4,6]');
 SELECT id, jt.* FROM t1,
   JSON_TABLE(jd, '$[*]' COLUMNS (jid FOR ORDINALITY,
                                  val INT PATH '$')) AS jt;
-SELECT /*+ JOIN_ORDER(jt, t1) */ id, jt.*
+SELECT id, jt.*
   FROM t1,
   JSON_TABLE(jd, '$[*]' COLUMNS (jid FOR ORDINALITY,
                                  val INT PATH '$')) AS jt;
 
-EXPLAIN SELECT /*+ JOIN_ORDER(jt, t1) */ id, jt.*
+EXPLAIN SELECT id, jt.*
   FROM t1,
   JSON_TABLE(jd, '$[*]' COLUMNS (jid FOR ORDINALITY,
                                  val INT PATH '$')) AS jt;
 
 --sorted_result
-SELECT /*+ JOIN_ORDER(t2,jt) */ t1.id, t2.id, jt.*
+SELECT t1.id, t2.id, jt.*
   FROM t1,
     JSON_TABLE(t1.jd, '$[*]' COLUMNS (jid FOR ORDINALITY,
                                       val INT PATH '$')) AS jt,
@@ -402,7 +402,7 @@ EXPLAIN SELECT t1.id, t2.id, jt.*
                                       val INT PATH '$')) AS jt,
     t1 AS t2;
 
-EXPLAIN SELECT /*+ JOIN_ORDER(t2,jt) */ t1.id, t2.id, jt.*
+EXPLAIN SELECT t1.id, t2.id, jt.*
   FROM t1,
     JSON_TABLE(t1.jd, '$[*]' COLUMNS (jid FOR ORDINALITY,
                                       val INT PATH '$')) AS jt,

sql/opt_hints.h

 /* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2024, MariaDB plc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -53,7 +54,7 @@ enum opt_hints_enum
 
 struct st_opt_hint_info
 {
-  const char* hint_name;  // Hint name.
+  LEX_CSTRING hint_name;  // Hint name.
   bool check_upper_lvl;   // true if upper level hint check is needed (for hints
                           // which can be specified on more than one level).
   bool switch_hint;       // true if hint is not complex.
@@ -81,7 +82,7 @@ class Opt_hints_map : public Sql_alloc
      Check if hint is specified.
 
      @param type_arg   hint type
-     
+
      @return true if hint is specified,
              false otherwise
   */
@@ -111,15 +112,13 @@ class Opt_hints_map : public Sql_alloc
 
      @return switch value.
   */
-  bool switch_on(opt_hints_enum type_arg) const
+  bool is_switched_on(opt_hints_enum type_arg) const
   {
     return hints.is_set(type_arg);
   }
 };
 
 
-class PT_hint;
-class PT_hint_max_execution_time;
 class Opt_hints_key;
 
 
@@ -129,15 +128,16 @@ class Opt_hints_key;
 
   Opt_hints_global class is hierarchical structure.
   It contains information about global hints and also
-  conains array of QUERY BLOCK level objects (Opt_hints_qb class).
+  contains array of QUERY BLOCK level objects (Opt_hints_qb class).
   Each QUERY BLOCK level object contains array of TABLE level hints
   (class Opt_hints_table). Each TABLE level hint contains array of
-  KEY lelev hints (Opt_hints_key class).
+  KEY level hints (Opt_hints_key class).
   Hint information(specified, on|off state) is stored in hints_map object.
 */
 
 class Opt_hints : public Sql_alloc
 {
+protected:
   /*
     Name of object referred by the hint.
     This name is empty for global level,
@@ -146,6 +146,7 @@ class Opt_hints : public Sql_alloc
     for key level.
   */
   Lex_ident_sys name;
+private:
   /*
     Parent object. There is no parent for global level,
     for query block level parent is Opt_hints_global object,
@@ -209,9 +210,14 @@ class Opt_hints : public Sql_alloc
   */
   bool get_switch(opt_hints_enum type_arg) const;
 
-  virtual const LEX_CSTRING *get_name() const
+  virtual CHARSET_INFO *charset_info() const
+  {
+    return Lex_ident_column::charset_info();
+  }
+
+  const LEX_CSTRING get_name() const
   {
-    return name.str ? &name : nullptr;
+    return name;
   }
   void set_name(const Lex_ident_sys &name_arg) { name= name_arg; }
   Opt_hints *get_parent() const { return parent; }
@@ -230,25 +236,11 @@ class Opt_hints : public Sql_alloc
     child_array.push_back(hint_arg);
   }
 
-  // OLEGS: remove it if not used
-  /**
-    Returns pointer to complex hint for a given type
-
-    @param type  hint type
-
-    @return  pointer to complex hint for a given type.
-  */
-  // virtual PT_hint *get_complex_hints(uint type)
-  // {
-  //   DBUG_ASSERT(0);
-  //   return NULL; /* error C4716: must return a value*/
-  // };
-
   /**
     Find hint among lower-level hint objects.
 
     @param name_arg        hint name
-  
+
     @return  hint if found,
              NULL otherwise
   */
@@ -303,16 +295,11 @@ class Opt_hints_global : public Opt_hints
 {
 
 public:
-  PT_hint_max_execution_time *max_exec_time;
- 
   Opt_hints_global(MEM_ROOT *mem_root_arg)
     : Opt_hints(Lex_ident_sys(), NULL, mem_root_arg)
-  {
-    max_exec_time= NULL;
-  }
+  {}
 
-  virtual void append_name(THD *thd, String *str) {}
-  virtual PT_hint *get_complex_hints(uint type);
+  virtual void append_name(THD *thd, String *str) override {}
 };
 
 
@@ -334,10 +321,9 @@ class Opt_hints_qb : public Opt_hints
                MEM_ROOT *mem_root_arg,
                uint select_number_arg);
 
-  const LEX_CSTRING *get_print_name()
+  const LEX_CSTRING get_print_name()
   {
-    const LEX_CSTRING *str= Opt_hints::get_name();
-    return str ? str : &sys_name;
+    return name.str ? name : sys_name;
   }
 
   /**
@@ -348,10 +334,10 @@ class Opt_hints_qb : public Opt_hints
   */
   void append_qb_hint(THD *thd, String *str)
   {
-    if (get_name())
+    if (name.str)
     {
       str->append(STRING_WITH_LEN("QB_NAME("));
-      append_identifier(thd, str, get_name()->str, get_name()->length);
+      append_identifier(thd, str, &name);
       str->append(STRING_WITH_LEN(") "));
     }
   }
@@ -361,10 +347,11 @@ class Opt_hints_qb : public Opt_hints
     @param thd   pointer to THD object
     @param str   pointer to String object
   */
-  virtual void append_name(THD *thd, String *str)
+  virtual void append_name(THD *thd, String *str) override
   {
     str->append(STRING_WITH_LEN("@"));
-    append_identifier(thd, str, get_print_name()->str, get_print_name()->length);
+    const LEX_CSTRING print_name= get_print_name();
+    append_identifier(thd, str, &print_name);
   }
 
   /**
@@ -399,15 +386,21 @@ class Opt_hints_table : public Opt_hints
       keyinfo_array(mem_root_arg)
   { }
 
+  CHARSET_INFO *charset_info() const override
+  {
+    return Lex_ident_table::charset_info();
+  }
+
+
   /**
     Append table name.
 
     @param thd   pointer to THD object
     @param str   pointer to String object
   */
-  virtual void append_name(THD *thd, String *str)
+  virtual void append_name(THD *thd, String *str) override
   {
-    append_identifier(thd, str, get_name()->str, get_name()->length);
+    append_identifier(thd, str, &name);
     get_parent()->append_name(thd, str);
   }
   /**
@@ -445,11 +438,11 @@ class Opt_hints_key : public Opt_hints
     @param thd   pointer to THD object
     @param str   pointer to String object
   */
-  virtual void append_name(THD *thd, String *str)
+  virtual void append_name(THD *thd, String *str) override
   {
     get_parent()->append_name(thd, str);
     str->append(' ');
-    append_identifier(thd, str, get_name()->str, get_name()->length);
+    append_identifier(thd, str, &name);
   }
 
   virtual uint get_warn_unresolved_code() const override
@@ -507,5 +500,4 @@ bool hint_table_state(const THD *thd, const TABLE *table,
 bool hint_table_state_or_fallback(const THD *thd, const TABLE *table,
                                   opt_hints_enum type_arg,
                                   bool fallback_value);
-
 #endif /* OPT_HINTS_INCLUDED */

sql/opt_hints_parser.cc

@@ -21,6 +21,7 @@
 #include "sql_error.h"
 #include "mysqld_error.h"
 #include "sql_class.h"
+#include "sql_show.h"
 
 
 extern struct st_opt_hint_info opt_hint_info[];

sql/opt_hints_parser.h

@@ -21,6 +21,7 @@
 #include "lex_ident_sys.h"
 #include "simple_tokenizer.h"
 #include "sql_list.h"
+#include "sql_string.h"
 #include "simple_parser.h"
 
 class st_select_lex;
@@ -565,7 +566,6 @@ class Optimizer_hint_parser: public Optimizer_hint_tokenizer,
   {
   public:
     using OR3::OR3;
-
   };
 
 
@@ -579,8 +579,6 @@ class Optimizer_hint_parser: public Optimizer_hint_tokenizer,
     size_t count() const { return elements; }
   };
 
-public:
-
   class Hint_list: public LIST<PARSER, Hint_list_container,
                                Hint, TokenID::tNULL/*not separated list*/, 1>
   {
@@ -590,6 +588,7 @@ class Optimizer_hint_parser: public Optimizer_hint_tokenizer,
     bool resolve(Parse_context *pc);
   };
 
+public:
   /*
     The main rule:
       hints ::= hint_list EOF
@@ -608,10 +607,10 @@ class Optimizer_hint_parser: public Optimizer_hint_tokenizer,
   instead of including the entire opt_hints_parser.h.
   (forward declarations of qualified nested classes are not possible in C++)
 */
-class Optimizer_hint_parser_output: public Optimizer_hint_parser::Hint_list
+class Optimizer_hint_parser_output: public Optimizer_hint_parser::Hints
 {
 public:
-  using Hint_list::Hint_list;
+  using Hints::Hints;
 };
 
 

sql/simple_parser.h

@@ -196,7 +196,7 @@ class Parser_templates
 
 
   /*
-    A rule consisting of three other rules in a row:
+    A rule consisting of four other rules in a row:
       rule ::= rule1 rule2 rule3 rule4
   */
   template<class PARSER, class A, class B, class C, class D>

sql/simple_tokenizer.h

@@ -17,7 +17,7 @@
 #define SIMPLE_TOKENIZER_INCLUDED
 
 
-#include "lex_ident.h"
+#include "lex_string.h"
 #include "scan_char.h"
 
 /**

sql/sql_lex.cc

@@ -3111,7 +3111,7 @@ void st_select_lex::init_query()
   pushdown_select= 0;
   orig_names_of_item_list_elems= 0;
   opt_hints_qb= 0;
-  parsed_optimizer_hints= 0; // OLEGS: remove if not used
+  parsed_optimizer_hints= 0;
 }
 
 void st_select_lex::init_select()
@@ -3166,7 +3166,7 @@ void st_select_lex::init_select()
   orig_names_of_item_list_elems= 0;
   item_list_usage= MARK_COLUMNS_READ;
   opt_hints_qb= 0;
-  parsed_optimizer_hints= 0; // OLEGS: remove if not used
+  parsed_optimizer_hints= 0;
 }
 
 /*
@@ -10684,6 +10684,7 @@ bool LEX::parsed_insert_select(SELECT_LEX *first_select)
     return true;
 
   // fix "main" select
+  resolve_optimizer_hints_in_last_select();
   SELECT_LEX *blt __attribute__((unused))= pop_select();
   DBUG_ASSERT(blt == &builtin_select);
   push_select(first_select);
@@ -12452,7 +12453,7 @@ LEX::parse_optimizer_hints(const Lex_comment_st &hints_str)
 }
 
 
-void LEX::resolve_optimizer_hints()
+void LEX::resolve_optimizer_hints_in_last_select()
 {
   SELECT_LEX *select_lex;
   if (likely(select_stack_top))

sql/sql_lex.h

@@ -1380,6 +1380,7 @@ class st_select_lex: public st_select_lex_node
   bool setup_ref_array(THD *thd, uint order_group_num);
   uint get_cardinality_of_ref_ptrs_slice(uint order_group_num_arg);
   void print(THD *thd, String *str, enum_query_type query_type);
+  void print_hints(THD *thd, String *hint_str);
   void print_item_list(THD *thd, String *str, enum_query_type query_type);
   void print_set_clause(THD *thd, String *str, enum_query_type query_type);
   void print_on_duplicate_key_clause(THD *thd, String *str,
@@ -3724,7 +3725,7 @@ struct LEX: public Query_tables_list
     DBUG_RETURN(select_lex);
   }
 
-  void resolve_optimizer_hints();
+  void resolve_optimizer_hints_in_last_select();
 
   SELECT_LEX *current_select_or_default()
   {

sql/sql_select.cc

@@ -31452,35 +31452,10 @@ void st_select_lex::print(THD *thd, String *str, enum_query_type query_type)
     return;
   }
 
-  char buff[NAME_LEN];
-  String hint_str(buff, sizeof(buff), system_charset_info);
-  hint_str.length(0);
-  if (thd->lex->opt_hints_global)
-  {
-    char tmp_buff[NAME_LEN];
-    String hints_tmp(tmp_buff, sizeof(tmp_buff), system_charset_info);
-    hints_tmp.length(0);
-    if (select_number == 1)
-    {
-      if (opt_hints_qb)
-        opt_hints_qb->append_qb_hint(thd, &hints_tmp);
-      thd->lex->opt_hints_global->print(thd, &hints_tmp);
-    }
-    else if (opt_hints_qb)
-      opt_hints_qb->append_qb_hint(thd, &hints_tmp);
-
-    if (hints_tmp.length() > 0)
-    {
-      hint_str.append(STRING_WITH_LEN("/*+ "));
-      hint_str.append(hints_tmp);
-      hint_str.append(STRING_WITH_LEN("*/ "));
-    }
-  }
-
-  if (hint_str.length() > 0 && (sel_type == SELECT_CMD ||
-                                sel_type == INSERT_CMD ||
-                                sel_type == REPLACE_CMD))
-    str->append(hint_str);
+  if (sel_type == SELECT_CMD ||
+      sel_type == INSERT_CMD ||
+      sel_type == REPLACE_CMD)
+    print_hints(thd, str);
 
   /* First add options */
   if (options & SELECT_STRAIGHT_JOIN)
@@ -31537,8 +31512,7 @@ void st_select_lex::print(THD *thd, String *str, enum_query_type query_type)
     if (sel_type == UPDATE_CMD || sel_type == DELETE_CMD)
     {
       str->append(get_explainable_cmd_name(sel_type));
-      if (hint_str.length() > 0)
-        str->append(hint_str);
+      print_hints(thd, str);
     }
     if (sel_type == DELETE_CMD)
     {
@@ -31668,6 +31642,36 @@ void st_select_lex::print(THD *thd, String *str, enum_query_type query_type)
 }
 
 
+void st_select_lex::print_hints(THD *thd,
+                                String *str)
+{
+  if (!thd->lex->opt_hints_global)
+    return;
+
+  constexpr LEX_CSTRING header={STRING_WITH_LEN("/*+ ")};
+  str->append(header);
+  uint32 len_before_hints= str->length();
+  if (select_number == 1)
+  {
+    if (opt_hints_qb)
+      opt_hints_qb->append_qb_hint(thd, str);
+    thd->lex->opt_hints_global->print(thd, str);
+  }
+  else if (opt_hints_qb)
+    opt_hints_qb->append_qb_hint(thd, str);
+
+  if (str->length() > len_before_hints)
+  {
+    // Some hints were printed, close the hint string
+    str->append(STRING_WITH_LEN("*/ "));
+  }
+  else
+  {
+    // No hints were added, rollback the previouly added header
+    str->length(len_before_hints - header.length);
+  }
+}
+
 /**
   Change the select_result object of the JOIN.
 

sql/sql_string.h

@@ -1011,10 +1011,6 @@ class String: public Charset, public Binary_string
   {
     return Binary_string::append(s);
   }
-  bool append(const char *s)
-  {
-    return append(s, (uint) strlen(s));
-  }
   inline bool append(char chr)
   {
     return Binary_string::append_char(chr);

sql/sql_yacc.yy

@@ -8765,6 +8765,7 @@ query_specification:
           opt_having_clause
           opt_window_clause
           {
+            Lex->resolve_optimizer_hints_in_last_select();
             $$= Lex->pop_select();
           }
         ;
@@ -8778,6 +8779,7 @@ select_into_query_specification:
           opt_having_clause
           opt_window_clause
           {
+            Lex->resolve_optimizer_hints_in_last_select();
             $$= Lex->pop_select();
           }
         ;
@@ -8917,7 +8919,6 @@ query_expression_body:
           query_simple
           {
             Lex->push_select($1);
-            Lex->resolve_optimizer_hints();
             if (!($$= Lex->create_unit($1)))
               MYSQL_YYABORT;
           }
@@ -13338,7 +13339,7 @@ insert:
           insert_field_spec opt_insert_update opt_returning
           insert_stmt_end
           {
-            Lex->resolve_optimizer_hints();
+            Lex->resolve_optimizer_hints_in_last_select();
             Lex->mark_first_table_as_inserting();
             thd->get_stmt_da()->reset_current_row_for_warning(0);
           }
@@ -13358,8 +13359,9 @@ replace:
             Select->set_lock_for_tables($5, true, false);
           }
           insert_field_spec opt_returning
-          stmt_end
+          insert_stmt_end
           {
+            Lex->resolve_optimizer_hints_in_last_select();
             Lex->mark_first_table_as_inserting();
             thd->get_stmt_da()->reset_current_row_for_warning(0);
           }
@@ -13375,7 +13377,7 @@ insert_start: {
               ;
 
 stmt_end: {
-              Lex->resolve_optimizer_hints();
+              Lex->resolve_optimizer_hints_in_last_select();
               Lex->pop_select(); //main select
               if (Lex->check_main_unit_semantics())
                 MYSQL_YYABORT;
@@ -13742,7 +13744,7 @@ delete:
           {
             if (Lex->check_cte_dependencies_and_resolve_references())
               MYSQL_YYABORT;
-            Lex->resolve_optimizer_hints();
+            Lex->resolve_optimizer_hints_in_last_select();
           }
           ;