MDEV-37292 Hint NO_INDEX() disables all indexes if none of given index names is resolved

When a hint has a list of index names, for example,
  `NO_INDEX(t1 idx1, idx2)`
there is a possibility that some or all of the listed index names will
not be resolved. If none of them are resolved, the hint becomes a table-level
hint, for example, `NO_INDEX(t1)`, which erroneously disables all indexes
of `t1` instead of disabling only some of them.

This commit addresses this issue by adding an additional check: a hint
containing a list of index names is considered resolved only when at least one
of the listed names is resolved successfully.

mysql-test/main/opt_hints_index.result

@@ -272,3 +272,96 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 Warnings:
 Note	1003	delete /*+ NO_INDEX(`t1`@`select#1` `i_ab`) */  from `test`.`t1` using dual where `test`.`t1`.`a` = 1 and `test`.`t1`.`b` = 2 and `test`.`t1`.`c` = 3
 DROP TABLE t1;
+#
+# Hint NO_INDEX() disables all indexes if none of given index names is not resolved
+#
+CREATE TABLE t1 (
+a INT,
+b INT,
+PRIMARY KEY(a),
+KEY ab(a, b)
+);
+INSERT INTO t1 VALUES (1,1),(2,2),(3,3),(4,4);
+ANALYZE TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	Engine-independent statistics collected
+test.t1	analyze	status	OK
+# By default, the index `ab` is used for grouping
+EXPLAIN EXTENDED SELECT a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	NULL	ab	4	NULL	4	100.00	Using index for group-by
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+# Invalid index names are ignored, index `ab` is still used
+EXPLAIN EXTENDED SELECT /*+ NO_GROUP_INDEX(t1 bbb)*/ a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	NULL	ab	4	NULL	4	100.00	Using index for group-by
+Warnings:
+Warning	4222	Unresolved index name `t1`@`select#1` `bbb` for NO_GROUP_INDEX hint
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+EXPLAIN EXTENDED SELECT /*+ NO_GROUP_INDEX(t1 bbb, abcd)*/ a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	NULL	ab	4	NULL	4	100.00	Using index for group-by
+Warnings:
+Warning	4222	Unresolved index name `t1`@`select#1` `bbb` for NO_GROUP_INDEX hint
+Warning	4222	Unresolved index name `t1`@`select#1` `abcd` for NO_GROUP_INDEX hint
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+EXPLAIN EXTENDED SELECT /*+ NO_GROUP_INDEX(t1 bbb, abcd, PRIMARY)*/ a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	NULL	ab	4	NULL	4	100.00	Using index for group-by
+Warnings:
+Warning	4222	Unresolved index name `t1`@`select#1` `bbb` for NO_GROUP_INDEX hint
+Warning	4222	Unresolved index name `t1`@`select#1` `abcd` for NO_GROUP_INDEX hint
+Note	1003	select /*+ NO_GROUP_INDEX(`t1`@`select#1` `bbb`,`abcd`,`PRIMARY`) */ `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+# This hint disables all indexes for grouping, so effectively it is the same
+# as table-level hint NO_GROUP_INDEX(t1)
+EXPLAIN EXTENDED SELECT /*+ NO_GROUP_INDEX(t1 bbb, dcba, PRIMARY, ab)*/ a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index; Using filesort
+Warnings:
+Warning	4222	Unresolved index name `t1`@`select#1` `bbb` for NO_GROUP_INDEX hint
+Warning	4222	Unresolved index name `t1`@`select#1` `dcba` for NO_GROUP_INDEX hint
+Note	1003	select /*+ NO_GROUP_INDEX(`t1`@`select#1` `bbb`,`dcba`,`PRIMARY`,`ab`) */ `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+# Compare the previous case with the table-level hint, results are the same:
+EXPLAIN EXTENDED SELECT /*+ NO_GROUP_INDEX(t1)*/ a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index; Using filesort
+Warnings:
+Note	1003	select /*+ NO_GROUP_INDEX(`t1`@`select#1`) */ `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+# Same set of tests as above but for the global `NO_INDEX()` hint
+EXPLAIN EXTENDED SELECT/*+ NO_INDEX(t1 bbb)*/ a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	NULL	ab	4	NULL	4	100.00	Using index for group-by
+Warnings:
+Warning	4222	Unresolved index name `t1`@`select#1` `bbb` for NO_INDEX hint
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+EXPLAIN EXTENDED SELECT/*+ NO_INDEX(t1 bbb, abcd)*/ a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	NULL	ab	4	NULL	4	100.00	Using index for group-by
+Warnings:
+Warning	4222	Unresolved index name `t1`@`select#1` `bbb` for NO_INDEX hint
+Warning	4222	Unresolved index name `t1`@`select#1` `abcd` for NO_INDEX hint
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+EXPLAIN EXTENDED SELECT/*+ NO_INDEX(t1 bbb, abcd, PRIMARY)*/ a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	range	NULL	ab	4	NULL	4	100.00	Using index for group-by
+Warnings:
+Warning	4222	Unresolved index name `t1`@`select#1` `bbb` for NO_INDEX hint
+Warning	4222	Unresolved index name `t1`@`select#1` `abcd` for NO_INDEX hint
+Note	1003	select /*+ NO_INDEX(`t1`@`select#1` `bbb`,`abcd`,`PRIMARY`) */ `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+EXPLAIN EXTENDED SELECT/*+ NO_INDEX(t1 bbb, abcd, PRIMARY, ab)*/ a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	100.00	Using filesort
+Warnings:
+Warning	4222	Unresolved index name `t1`@`select#1` `bbb` for NO_INDEX hint
+Warning	4222	Unresolved index name `t1`@`select#1` `abcd` for NO_INDEX hint
+Note	1003	select /*+ NO_INDEX(`t1`@`select#1` `bbb`,`abcd`,`PRIMARY`,`ab`) */ `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+EXPLAIN EXTENDED SELECT/*+ NO_INDEX(t1)*/ a FROM t1 GROUP BY a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	100.00	Using filesort
+Warnings:
+Note	1003	select /*+ NO_INDEX(`t1`@`select#1`) */ `test`.`t1`.`a` AS `a` from `test`.`t1` group by `test`.`t1`.`a`
+DROP TABLE t1;
+#
+# End of 12.1 tests
+#

mysql-test/main/opt_hints_index.test

@@ -112,3 +112,48 @@ EXPLAIN EXTENDED DELETE FROM t1 WHERE a = 1 AND b = 2 AND c = 3;
 EXPLAIN EXTENDED DELETE /*+ NO_INDEX(t1 i_ab) */ FROM t1 WHERE a = 1 AND b = 2 AND c = 3;
 
 DROP TABLE t1;
+
+--echo #
+--echo # Hint NO_INDEX() disables all indexes if none of given index names is not resolved
+--echo #
+
+CREATE TABLE t1 (
+  a INT,
+  b INT,
+  PRIMARY KEY(a),
+  KEY ab(a, b)
+);
+INSERT INTO t1 VALUES (1,1),(2,2),(3,3),(4,4);
+
+ANALYZE TABLE t1;
+
+# Warnings "Unresolved table/index name..." are generated during both prepare
+# and execution stages. So disable PS protocol to avoid duplication
+--disable_ps_protocol
+
+--echo # By default, the index `ab` is used for grouping
+EXPLAIN EXTENDED SELECT a FROM t1 GROUP BY a;
+--echo # Invalid index names are ignored, index `ab` is still used
+EXPLAIN EXTENDED SELECT /*+ NO_GROUP_INDEX(t1 bbb)*/ a FROM t1 GROUP BY a;
+EXPLAIN EXTENDED SELECT /*+ NO_GROUP_INDEX(t1 bbb, abcd)*/ a FROM t1 GROUP BY a;
+EXPLAIN EXTENDED SELECT /*+ NO_GROUP_INDEX(t1 bbb, abcd, PRIMARY)*/ a FROM t1 GROUP BY a;
+
+--echo # This hint disables all indexes for grouping, so effectively it is the same
+--echo # as table-level hint NO_GROUP_INDEX(t1)
+EXPLAIN EXTENDED SELECT /*+ NO_GROUP_INDEX(t1 bbb, dcba, PRIMARY, ab)*/ a FROM t1 GROUP BY a;
+--echo # Compare the previous case with the table-level hint, results are the same:
+EXPLAIN EXTENDED SELECT /*+ NO_GROUP_INDEX(t1)*/ a FROM t1 GROUP BY a;
+
+--echo # Same set of tests as above but for the global `NO_INDEX()` hint
+EXPLAIN EXTENDED SELECT/*+ NO_INDEX(t1 bbb)*/ a FROM t1 GROUP BY a;
+EXPLAIN EXTENDED SELECT/*+ NO_INDEX(t1 bbb, abcd)*/ a FROM t1 GROUP BY a;
+EXPLAIN EXTENDED SELECT/*+ NO_INDEX(t1 bbb, abcd, PRIMARY)*/ a FROM t1 GROUP BY a;
+EXPLAIN EXTENDED SELECT/*+ NO_INDEX(t1 bbb, abcd, PRIMARY, ab)*/ a FROM t1 GROUP BY a;
+EXPLAIN EXTENDED SELECT/*+ NO_INDEX(t1)*/ a FROM t1 GROUP BY a;
+
+--enable_ps_protocol
+DROP TABLE t1;
+
+--echo #
+--echo # End of 12.1 tests
+--echo #

sql/opt_hints.cc

@@ -552,14 +552,6 @@ bool Opt_hints_table::fix_key_hints(TABLE *table)
     fixing the child objects.
   */
   set_fixed();
-  if (is_specified(INDEX_HINT_ENUM))
-    global_index_map.set_fixed();
-  if (is_specified(JOIN_INDEX_HINT_ENUM))
-    join_index_map.set_fixed();
-  if (is_specified(GROUP_INDEX_HINT_ENUM))
-    group_index_map.set_fixed();
-  if (is_specified(ORDER_INDEX_HINT_ENUM))
-    order_index_map.set_fixed();
 
   /* Make sure that adjustment is called only once. */
   DBUG_ASSERT(keyinfo_array.size() == 0);
@@ -582,6 +574,26 @@ bool Opt_hints_table::fix_key_hints(TABLE *table)
     }
   }
 
+  /*
+    Fixing compound index hints. A compound hint is fixed in two cases:
+    - it is a table-level hint, i.e. does not have a list of index names
+          (like ORDER_INDEX(t1);
+    - it has a list of index names, and at least one of listed
+      index names is resolved successfully. So, NO_INDEX(t1 bad_idx) does not
+      become a table-level hint NO_INDEX(t1) if `bad_idx` cannnot be resolved.
+  */
+  for (opt_hints_enum
+           hint_type : { INDEX_HINT_ENUM, JOIN_INDEX_HINT_ENUM,
+                         GROUP_INDEX_HINT_ENUM, ORDER_INDEX_HINT_ENUM })
+  {
+    if (is_specified(hint_type))
+    {
+      Opt_hints_key_bitmap *bitmap= get_key_hint_bitmap(hint_type);
+      if (bitmap->is_table_level() || bitmap->bits_set() > 0)
+        bitmap->set_fixed();
+    }
+  }
+
   if (are_children_fully_fixed())
     return false;
 

sql/opt_hints.h

@@ -648,10 +648,12 @@ public:
 
   void set_fixed() { fixed= true; }
   bool is_fixed() const { return fixed; }
+  bool is_table_level() const { return parsed_hint->is_table_level_hint(); }
 
   void set_key_map(uint i) { key_map.set_bit(i); }
   bool is_set_key_map(uint i) { return key_map.is_set(i); }
   bool is_key_map_clear_all() { return key_map.is_clear_all(); }
+  uint bits_set() { return key_map.bits_set(); }
   Key_map *get_key_map() { return &key_map; }
 };
 

sql/opt_hints_parser.cc

@@ -588,7 +588,13 @@ bool Parser::Index_level_hint::resolve(Parse_context *pc) const
   const Lex_ident_sys key_conflict(
       STRING_WITH_LEN("another hint was already specified for this index"));
 
-  if (is_empty())  // Empty list of index names, i.e. it is a table level hint
+  /*
+    If no index names are given, this is a table level hint, for example:
+    GROUP_INDEX(t1), NO_MRR(t2).
+    Otherwise this is a group of index-level hints:
+    NO_INDEX(t1 idx1, idx2) NO_ICP(t2 idx_a, idx_b, idx_c)
+  */
+  if (is_empty())
   {
     uint warn_code= 0;
     if (is_compound_hint(hint_type) &&

sql/opt_hints_parser.h

@@ -656,6 +656,14 @@ public:
   public:
     using AND4::AND4;
 
+    /*
+      If no index names are given, this is a table level hint, for example:
+      GROUP_INDEX(t1), NO_MRR(t2).
+      Otherwise this is an index-level hints:
+      NO_INDEX(t1 idx1, idx2) NO_ICP(t2 idx_a, idx_b, idx_c)
+    */
+    bool is_table_level_hint() const { return is_empty(); }
+
     bool resolve(Parse_context *pc) const;
     void append_args(THD *thd, String *str) const override;
   };