MDEV-36486 Forbid placing optimizer hints at the INSERT part of INSERT..SELECT

Due to complications while parsing of INSERT..SELECT statements,
optimizer hints placed at the INSERT part are ignored.

At the same time, hints placed at the SELECT part of
INSERT..SELECT statements are fully supported.

Author: Olernov

mysql-test/main/opt_hint_timeout.result

@@ -72,10 +72,16 @@ Warning	1912	Incorrect value '4294967296' for option 'MAX_EXECUTION_TIME'
 CREATE TABLE t2 (i INT);
 INSERT /*+ MAX_EXECUTION_TIME(10) */ INTO t2 SELECT 1;
 Warnings:
+Warning	4223	Optimizer hints at the INSERT part of a INSERT..SELECT statement are not supported
+INSERT INTO t2 SELECT /*+ MAX_EXECUTION_TIME(10) */ 1;
+Warnings:
 Warning	4172	'MAX_EXECUTION_TIME(10)' is not allowed in this context
 REPLACE /*+ MAX_EXECUTION_TIME(15) */ INTO t2 SELECT 1;
 Warnings:
-Warning	4172	'MAX_EXECUTION_TIME(15)' is not allowed in this context
+Warning	4223	Optimizer hints at the INSERT part of a INSERT..SELECT statement are not supported
+REPLACE INTO t2 SELECT /*+ MAX_EXECUTION_TIME(10) */ 1;
+Warnings:
+Warning	4172	'MAX_EXECUTION_TIME(10)' is not allowed in this context
 UPDATE /*+ MAX_EXECUTION_TIME(23) */ t2 SET i = 1;
 Warnings:
 Warning	4172	'MAX_EXECUTION_TIME(23)' is not allowed in this context

mysql-test/main/opt_hint_timeout.test

@@ -78,7 +78,9 @@ SELECT /*+ MAX_EXECUTION_TIME(4294967296) */ count(*) FROM t1;
 --echo
 CREATE TABLE t2 (i INT);
 INSERT /*+ MAX_EXECUTION_TIME(10) */ INTO t2 SELECT 1;
+INSERT INTO t2 SELECT /*+ MAX_EXECUTION_TIME(10) */ 1;
 REPLACE /*+ MAX_EXECUTION_TIME(15) */ INTO t2 SELECT 1;
+REPLACE INTO t2 SELECT /*+ MAX_EXECUTION_TIME(10) */ 1;
 UPDATE /*+ MAX_EXECUTION_TIME(23) */ t2 SET i = 1;
 DELETE /*+ MAX_EXECUTION_TIME(5000) */ FROM t2 WHERE i = 1;
 

mysql-test/main/opt_hints.result

@@ -490,17 +490,17 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 Warnings:
 Note	1003	(insert into `test`.`t3`(f1,f2,f3) select /*+ NO_ICP(`t5`@`select#2`) */ `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
-EXPLAIN EXTENDED INSERT /*+ NO_ICP(t5@QB1) */ INTO t3(f1, f2, f3)
-(SELECT /*+ QB_NAME(qb1) */ t4.x, t5.y, 'filler' FROM t4, t4 t5
+EXPLAIN EXTENDED INSERT 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);
 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	
 1	SIMPLE	t5	range	x_idx	x_idx	5	NULL	2	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
-Note	1003	(insert into `test`.`t3`(f1,f2,f3) select /*+ QB_NAME(`qb1`) NO_ICP(`t5`@`qb1`) */ `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))
+Note	1003	(insert into `test`.`t3`(f1,f2,f3) select /*+ NO_ICP(`t5`@`select#2`) */ `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 /*+ NO_ICP(t5@QB1 x_idx) */ INTO t3(f1, f2, f3)
-(SELECT /*+ QB_NAME(qb1) */ t4.x, t5.y, 'filler' FROM t4, t4 t5 
+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
 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	
@@ -525,23 +525,23 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 Warnings:
 Note	1003	(replace into `test`.`t3`(f1,f2,f3) select /*+ NO_ICP(`t5`@`select#2`) */ `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
-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
+EXPLAIN EXTENDED REPLACE INTO t3(f1, f2, f3)
+(SELECT /*+ QB_NAME(qb1) NO_ICP(t5@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	
 1	SIMPLE	t5	range	x_idx	x_idx	5	NULL	2	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	(replace into `test`.`t3`(f1,f2,f3) select /*+ QB_NAME(`qb1`) NO_ICP(`t5`@`qb1`) */ `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 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
+EXPLAIN EXTENDED REPLACE INTO t3(f1, f2, f3)
+(SELECT /*+ NO_ICP(t5 x_idx) */ 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	
 1	SIMPLE	t5	range	x_idx	x_idx	5	NULL	2	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
-Note	1003	(replace into `test`.`t3`(f1,f2,f3) select /*+ QB_NAME(`qb1`) NO_ICP(`t5`@`qb1` `x_idx`) */ `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))
+Note	1003	(replace into `test`.`t3`(f1,f2,f3) select /*+ NO_ICP(`t5`@`select#2` `x_idx`) */ `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))
 # Misc tests
 # Should issue warning
 EXPLAIN EXTENDED SELECT /*+ QB_NAME(qb1) QB_NAME(qb1 ) */ * FROM t2;
@@ -1400,21 +1400,23 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	a	a	5	NULL	3	100.00	Using where; Using index; Using temporary
 Warnings:
 Note	1003	insert into `test`.`t1`(a) select /*+ NO_RANGE_OPTIMIZATION(`t1`@`select#2` `a`) */ sql_buffer_result `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` > 1 and `test`.`t1`.`a` <= 3
-# Alternatively, a hint may be placed next to INSERT keyword:
+# Hints at the INSERT part of a INSERT..SELECT are not supported:
 EXPLAIN EXTENDED
 INSERT  /*+ no_range_optimization (t1)*/ INTO t1 (a) SELECT a FROM t1 WHERE a>1 AND a<=3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	index	a	a	5	NULL	3	100.00	Using where; Using index; Using temporary
+1	SIMPLE	t1	range	a	a	5	NULL	2	100.00	Using where; Using index; Using temporary
 Warnings:
-Note	1003	insert into `test`.`t1`(a) select /*+ NO_RANGE_OPTIMIZATION(`t1`@`select#1`) */ sql_buffer_result `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` > 1 and `test`.`t1`.`a` <= 3
-# But if hints are present at both INSERT and SELECT parts,
-# those at the INSERT part are ignored:
+Warning	4223	Optimizer hints at the INSERT part of a INSERT..SELECT statement are not supported
+Note	1003	insert into `test`.`t1`(a) select sql_buffer_result `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` > 1 and `test`.`t1`.`a` <= 3
+# If hints are present at both INSERT and SELECT parts,
+# those at the INSERT part are ignored
 EXPLAIN EXTENDED
 INSERT  /*+ no_range_optimization (t1)*/ INTO t1 (a) SELECT /*+ mrr(t1)*/ a 
 FROM t1 WHERE a>1 AND a<=3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	range	a	a	5	NULL	2	100.00	Using where; Using index; Using temporary
 Warnings:
+Warning	4223	Optimizer hints at the INSERT part of a INSERT..SELECT statement are not supported
 Note	1003	insert into `test`.`t1`(a) select /*+ MRR(`t1`@`select#2`) */ sql_buffer_result `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` > 1 and `test`.`t1`.`a` <= 3
 # Table `t2` cannot be resolved since it is not present in the SELECT part
 # (a warning expected):
@@ -1423,15 +1425,7 @@ INSERT INTO t2 (a) SELECT /*+ no_range_optimization (t2)*/ a FROM t1 WHERE a>1 A
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	range	a	a	5	NULL	2	100.00	Using where; Using index
 Warnings:
-Warning	4212	Unresolved table name `t2`@`select#2` for NO_RANGE_OPTIMIZATION hint
-Note	1003	insert into `test`.`t2`(a) select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` > 1 and `test`.`t1`.`a` <= 3
-# Alternative placement of the hint:
-EXPLAIN EXTENDED
-INSERT /*+ no_range_optimization (t2 ix1)*/ INTO t2 (a) SELECT a FROM t1 WHERE a>1 AND a<=3;
-id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	2	100.00	Using where; Using index
-Warnings:
-Warning	4213	Unresolved index name `t2`@`select#1` `ix1` for NO_RANGE_OPTIMIZATION hint
+Warning	4219	Unresolved table name `t2`@`select#2` for NO_RANGE_OPTIMIZATION hint
 Note	1003	insert into `test`.`t2`(a) select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` > 1 and `test`.`t1`.`a` <= 3
 DROP TABLE t1, t2;
 set optimizer_switch = DEFAULT;

mysql-test/main/opt_hints.test

@@ -275,13 +275,13 @@ EXPLAIN EXTENDED INSERT INTO t3(f1, f2, f3)
    WHERE t4.y = 8 AND t5.x BETWEEN 7 AND t4.y+0);
 
 --echo # Turn off ICP for a particular table
-EXPLAIN EXTENDED INSERT /*+ NO_ICP(t5@QB1) */ INTO t3(f1, f2, f3)
-  (SELECT /*+ QB_NAME(qb1) */ t4.x, t5.y, 'filler' FROM t4, t4 t5
+EXPLAIN EXTENDED INSERT 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 and a key
-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 
+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
    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
@@ -294,13 +294,13 @@ EXPLAIN EXTENDED REPLACE INTO t3(f1, f2, f3)
    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
+EXPLAIN EXTENDED REPLACE INTO t3(f1, f2, f3)
+  (SELECT /*+ QB_NAME(qb1) NO_ICP(t5@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
+EXPLAIN EXTENDED REPLACE INTO t3(f1, f2, f3)
+  (SELECT /*+ NO_ICP(t5 x_idx) */ 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
@@ -723,24 +723,24 @@ INSERT INTO t1 (a) SELECT a FROM t1 WHERE a>1 AND a<=3;
 EXPLAIN EXTENDED
 INSERT INTO t1 (a) SELECT /*+ no_range_optimization (t1 a)*/ a FROM t1 WHERE a>1 AND a<=3;
 
---echo # Alternatively, a hint may be placed next to INSERT keyword:
+--echo # Hints at the INSERT part of a INSERT..SELECT are not supported:
 EXPLAIN EXTENDED
 INSERT  /*+ no_range_optimization (t1)*/ INTO t1 (a) SELECT a FROM t1 WHERE a>1 AND a<=3;
 
---echo # But if hints are present at both INSERT and SELECT parts,
---echo # those at the INSERT part are ignored:
+--echo # If hints are present at both INSERT and SELECT parts,
+--echo # those at the INSERT part are ignored
 EXPLAIN EXTENDED
 INSERT  /*+ no_range_optimization (t1)*/ INTO t1 (a) SELECT /*+ mrr(t1)*/ a 
   FROM t1 WHERE a>1 AND a<=3;
 
 --echo # Table `t2` cannot be resolved since it is not present in the SELECT part
 --echo # (a warning expected):
+# Warnings "Unresolved table/index name..." are generated during both prepare
+# and execution stages. So disable PS protocol to avoid duplication
+--disable_ps_protocol
 EXPLAIN EXTENDED
 INSERT INTO t2 (a) SELECT /*+ no_range_optimization (t2)*/ a FROM t1 WHERE a>1 AND a<=3;
-
---echo # Alternative placement of the hint:
-EXPLAIN EXTENDED
-INSERT /*+ no_range_optimization (t2 ix1)*/ INTO t2 (a) SELECT a FROM t1 WHERE a>1 AND a<=3;
+--enable_ps_protocol
 
 DROP TABLE t1, t2;
 

mysql-test/main/opt_hints_join_cache.test

@@ -1,3 +1,5 @@
+--disable_view_protocol # Since optimizer hints are not supported inside views
+
 set @tmp_jcl= @@join_cache_level;
 set @tmp_opt= @@optimizer_switch;
 

mysql-test/main/opt_hints_join_order.result

@@ -1336,6 +1336,14 @@ INSERT INTO t2 (id, f2) VALUES
 (4,5),(3,3),(1,0),(1,3),(6,1),(2,0),(4,1),(2,7),(2,1),(1,0),(3,0),(5,8),(5,4),
 (3,9),(2,0),(7,2),(2,0),(1,8),(6,5),(4,1);
 CREATE TABLE tn (fn_1 INT, fn_2 INT);
+ANALYZE TABLE t1, t2, tn;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	Engine-independent statistics collected
+test.t1	analyze	status	OK
+test.t2	analyze	status	Engine-independent statistics collected
+test.t2	analyze	status	OK
+test.tn	analyze	status	Engine-independent statistics collected
+test.tn	analyze	status	OK
 EXPLAIN EXTENDED
 INSERT INTO tn (fn_1, fn_2)
 SELECT /*+ JOIN_ORDER(t2,t1) JOIN_FIXED_ORDER() */ f1,f2

mysql-test/main/opt_hints_join_order.test

@@ -807,6 +807,8 @@ INSERT INTO t2 (id, f2) VALUES
 
 CREATE TABLE tn (fn_1 INT, fn_2 INT);
 
+ANALYZE TABLE t1, t2, tn;
+
 EXPLAIN EXTENDED
 INSERT INTO tn (fn_1, fn_2)
   SELECT /*+ JOIN_ORDER(t2,t1) JOIN_FIXED_ORDER() */ f1,f2

sql/share/errmsg-utf8.txt

@@ -12325,3 +12325,5 @@ ER_HINTS_INSIDE_VIEWS_NOT_SUPPORTED
         eng "Optimizer hints are not supported inside view definitions"
 ER_WARN_MALFORMED_HINT
         eng "Hint %s is ignored as malformed"
+ER_WARN_HINTS_ON_INSERT_PART_OF_INSERT_SELECT
+        eng "Optimizer hints at the INSERT part of a INSERT..SELECT statement are not supported"

sql/sql_lex.cc

@@ -11185,22 +11185,17 @@ bool LEX::parsed_insert_select(SELECT_LEX *first_select)
     return true;
 
   // fix "main" select
-  resolve_optimizer_hints_in_last_select();
+  if (discard_optimizer_hints_in_last_select())
+  {
+    // Hints were specified at the INSERT part of an INSERT..SELECT
+    push_warning(thd, Sql_condition::WARN_LEVEL_WARN,
+                 ER_WARN_HINTS_ON_INSERT_PART_OF_INSERT_SELECT,
+                 ER_THD(thd, ER_WARN_HINTS_ON_INSERT_PART_OF_INSERT_SELECT));
+  }
   SELECT_LEX *blt __attribute__((unused))= pop_select();
   DBUG_ASSERT(blt == &builtin_select);
   push_select(first_select);
 
-  // INSERT..SELECT allows placing hints next to either INSERT or SELECT, i.e.:
-  //  `INSERT /* hint(t1) */ INTO t2 SELECT a FROM t1` or
-  //  `INSERT INTO t2 SELECT /* hint(t1) */ a FROM t1`
-  // but not at both places at the same time.
-  // `first_select` represents the SELECT part here while `builtin_select` -
-  // the INSERT part. Future processing will proceed with `first_select`,
-  // so transfer the hints from `builtin_select` to `first_select` in case
-  // they were not already set. If hints are present for both INSERT and SELECT
-  // parts, SELECT part hints are preserved while INSERT part hints are discarded
-  if (!first_select->opt_hints_qb && blt->opt_hints_qb)
-    first_select->opt_hints_qb= blt->opt_hints_qb;
   return false;
 }
 
@@ -13004,3 +12999,30 @@ void LEX::resolve_optimizer_hints_in_last_select()
     select_lex->parsed_optimizer_hints->resolve(&pc);
   }
 }
+
+/*
+  This method discards previously parsed optimizer hints attached to
+  the last select_lex without their resolving, which may be required
+  in some scenarios (for example, ignoring hints at the INSERT part of a
+  INSERT..SELECT statement).
+
+  Also see resolve_optimizer_hints_in_last_select().
+
+  Return value:
+  - false  optimizer hints were not found
+  - true   optimizer hints were found and discarded
+*/
+bool LEX::discard_optimizer_hints_in_last_select()
+{
+  SELECT_LEX *select_lex;
+  if (likely(select_stack_top))
+    select_lex= select_stack[select_stack_top - 1];
+  else
+    select_lex= nullptr;
+  if (select_lex && select_lex->parsed_optimizer_hints)
+  {
+    select_lex->parsed_optimizer_hints= nullptr;
+    return true;
+  }
+  return false;
+}

sql/sql_lex.h

@@ -3758,6 +3758,8 @@ struct LEX: public Query_tables_list
 
   void resolve_optimizer_hints_in_last_select();
 
+  bool discard_optimizer_hints_in_last_select();
+
   SELECT_LEX *current_select_or_default()
   {
     return current_select ? current_select : &builtin_select;