diff --git a/mysql-test/include/oversized_varchar_key.inc b/mysql-test/include/oversized_varchar_key.inc
new file mode 100644
index 000000000000..fc2c41727744
--- /dev/null
+++ b/mysql-test/include/oversized_varchar_key.inc
@@ -0,0 +1,181 @@
+eval CREATE TABLE t1 ( pk VARCHAR(16) NOT NULL PRIMARY KEY ) CHARSET=$charset COLLATE=$collation;
+
+INSERT INTO t1 VALUES ('abc'), ('def'), ('ghi'), ('jkl'), ('mno');
+ANALYZE TABLE t1;
+
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16');
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16');
+
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16', 'and_so_is_this_one');
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16', 'and_so_is_this_one');
+
+
+eval CREATE TABLE t2 ( a VARCHAR(1), KEY (a) ) CHARSET=$charset COLLATE=$collation;
+
+INSERT INTO t2 VALUES (NULL), ('a'), ('b'), ('æ'), ('ß'), ('s');
+INSERT INTO t2 SELECT 'x' FROM t2;
+INSERT INTO t2 SELECT 'x' FROM t2;
+
+ANALYZE TABLE t2;
+
+--echo # Strings containing soft hyphen (U+00AD) will not match for UTF-16
+
+EXPLAIN
+SELECT * FROM t2 WHERE a IN ('ae', concat(_utf8mb4 x'c2ad', 'b'), 'ss');
+SELECT * FROM t2 WHERE a IN ('ae', concat(_utf8mb4 x'c2ad', 'b'), 'ss');
+
+EXPLAIN
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae'), 'ss');
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae'), 'ss');
+
+
+EXPLAIN
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae', _utf8mb4 x'c2ad'), 'ss');
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae', _utf8mb4 x'c2ad'), 'ss');
+
+EXPLAIN
+SELECT * FROM t2 WHERE a = 'ae' OR a = concat(_utf8mb4 x'c2ad', 'b') OR a = 'ss';
+SELECT * FROM t2 WHERE a = 'ae' OR a = concat(_utf8mb4 x'c2ad', 'b') OR a = 'ss';
+
+--echo # The plan is unstable in this case, however it always uses an index, and results are consistent.
+--replace_column 5 X 10 X
+EXPLAIN
+SELECT * FROM t2 WHERE a IN ('ae', concat(repeat(_utf8mb4 x'c2ad', 2), 'b', repeat(_utf8mb4 x'c2ad', 2)));
+--echo # Adding handler statistics to show that execution is also consistent.
+FLUSH STATUS;
+SELECT * FROM t2 WHERE a IN ('ae', concat(repeat(_utf8mb4 x'c2ad', 2), 'b', repeat(_utf8mb4 x'c2ad', 2)));
+SHOW STATUS LIKE 'Handler_read_%';
+
+
+eval CREATE TABLE t3 ( a VARCHAR(768), KEY(a)) CHARSET=$charset COLLATE=$collation;
+
+INSERT INTO t3 VALUES( repeat('æ', 767) ), ( repeat('æ', 768) );
+
+ANALYZE TABLE t3;
+
+--replace_regex /'(.\uC3A6){767}'/'æ...'/
+EXPLAIN
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('æ', 767) );
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('æ', 767) );
+
+--replace_regex /'(ae){768}'/'ae..'/
+EXPLAIN
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 768) );
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 768) );
+
+--replace_regex /'(ae){769}'/'ae...'/
+EXPLAIN
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 769) );
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 769) );
+
+
+eval CREATE TABLE t4 ( a VARCHAR(100), KEY(a(50))) CHARSET=$charset COLLATE=$collation;
+
+INSERT INTO t4 VALUES ( repeat('æ', 98) ), ( repeat('æ', 99) ), ( repeat('æ', 100) );
+INSERT INTO t4 VALUES ( concat(repeat( 'a', 50 ), repeat( 'æ', 50 )) );
+
+ANALYZE TABLE t4;
+
+--replace_regex /'(.\uC3A6){98}'/'æ...'/
+EXPLAIN
+SELECT 1 FROM t4 WHERE a IN ( 'a', repeat('æ', 98) );
+SELECT 1 FROM t4 WHERE a IN ( 'a', repeat('æ', 98) );
+
+
+eval CREATE TABLE t5 ( a VARCHAR(16383), KEY(a(768))) CHARSET=$charset COLLATE=$collation;
+
+INSERT INTO t5 VALUES( repeat('æ', 16383) ), ( repeat('æ', 16382) ), ( repeat('æ', 16381) );
+
+ANALYZE TABLE t5;
+
+--replace_regex /'(.\uC3A6){16381}'/'æ...'/
+EXPLAIN
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16381) );
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16381) );
+
+--replace_regex /'(.\uC3A6){16382}'/'æ...'/
+EXPLAIN
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16382) );
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16382) );
+
+--replace_regex /'(.\uC3A6){16383}'/'æ...'/
+EXPLAIN
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16383) );
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16383) );
+
+
+eval CREATE TABLE t6 ( a VARCHAR(6),  KEY(a(3)) ) CHARSET=$charset COLLATE=$collation;
+
+INSERT INTO t6 VALUES ('aaaaaa'), ('æaaaaa'), ('ææaaaa'), ('æææaaa'), ('ææææaa'), ('æææææa'), ('ææææææ'),
+                      ('😊aaaaa'), ('😊æaaaa'), ('😊😊aaaa'), ('😊😊æaaa'), ('😊😊😊aaa');
+
+ANALYZE TABLE t6;
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'aaaaaa' );
+SELECT * FROM t6 WHERE a IN ( '', 'aaaaaa' );
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'æaaaaa' );
+SELECT * FROM t6 WHERE a IN ( '', 'æaaaaa' );
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'ææaaaa' );
+SELECT * FROM t6 WHERE a IN ( '', 'ææaaaa' );
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'æææaaa' );
+SELECT * FROM t6 WHERE a IN ( '', 'æææaaa' );
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'ææææaa' );
+SELECT * FROM t6 WHERE a IN ( '', 'ææææaa' );
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'æææææa' );
+SELECT * FROM t6 WHERE a IN ( '', 'æææææa' );
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'ææææææ' );
+SELECT * FROM t6 WHERE a IN ( '', 'ææææææ' );
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊aaaaa');
+SELECT * FROM t6 WHERE a IN ( '', '😊aaaaa');
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊æaaaa');
+SELECT * FROM t6 WHERE a IN ( '', '😊æaaaa');
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊😊aaaa');
+SELECT * FROM t6 WHERE a IN ( '', '😊😊aaaa');
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊😊æaaa');
+SELECT * FROM t6 WHERE a IN ( '', '😊😊😊aaa');
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ');
+SELECT * FROM t6 WHERE a IN ('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ');
+
+EXPLAIN
+SELECT * FROM t6 WHERE a IN
+    ('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ',
+     '😊aaaaa', '😊æaaaa', '😊😊aaaa', '😊😊æaaa', '😊😊😊aaa');
+SELECT * FROM t6 WHERE a IN
+    ('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ',
+     '😊aaaaa', '😊æaaaa', '😊😊aaaa', '😊😊æaaa', '😊😊😊aaa');
+
+
+DROP TABLE t1, t2, t3, t4, t5, t6;
diff --git a/mysql-test/r/type_varchar.result b/mysql-test/r/type_varchar.result
index 0a84407c1b93..d6408dd5d210 100644
--- a/mysql-test/r/type_varchar.result
+++ b/mysql-test/r/type_varchar.result
@@ -580,3 +580,704 @@ SELECT 5 = a FROM t1;
 Warnings:
 Warning	1292	Truncated incorrect DOUBLE value: 's'
 DROP TABLE t1;
+#
+# Bug#118009: SELECT query on primary key column deteriorates to full
+#             table scan when filter involves too long string
+#
+CREATE TABLE t1 ( pk VARCHAR(16) NOT NULL PRIMARY KEY ) CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
+INSERT INTO t1 VALUES ('abc'), ('def'), ('ghi'), ('jkl'), ('mno');
+ANALYZE TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	OK
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	NULL	index	PRIMARY	PRIMARY	66	NULL	5	60.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`pk` AS `pk` from `test`.`t1` where (`test`.`t1`.`pk` in ('abc','this_value_is_>16','def'))
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+pk
+abc
+def
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	NULL	index	PRIMARY	PRIMARY	66	NULL	5	60.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`pk` AS `pk` from `test`.`t1` where (`test`.`t1`.`pk` in ('abc','this_value_is_>16','def'))
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+pk
+abc
+def
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+Warnings:
+Note	1003	/* select#1 */ select NULL AS `pk` from `test`.`t1` where multiple equal('this_value_is_>16', NULL)
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16');
+pk
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16', 'and_so_is_this_one');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	NULL	range	PRIMARY	PRIMARY	66	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`pk` AS `pk` from `test`.`t1` where (`test`.`t1`.`pk` in ('this_value_is_>16','and_so_is_this_one'))
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16', 'and_so_is_this_one');
+pk
+CREATE TABLE t2 ( a VARCHAR(1), KEY (a) ) CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
+INSERT INTO t2 VALUES (NULL), ('a'), ('b'), ('æ'), ('ß'), ('s');
+INSERT INTO t2 SELECT 'x' FROM t2;
+INSERT INTO t2 SELECT 'x' FROM t2;
+ANALYZE TABLE t2;
+Table	Op	Msg_type	Msg_text
+test.t2	analyze	status	OK
+# Strings containing soft hyphen (U+00AD) will not match for UTF-16
+EXPLAIN
+SELECT * FROM t2 WHERE a IN ('ae', concat(_utf8mb4 x'c2ad', 'b'), 'ss');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	NULL	range	a	a	7	NULL	3	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where (`test`.`t2`.`a` in ('ae',<cache>(concat(_utf8mb4'\xC2\xAD','b')),'ss'))
+SELECT * FROM t2 WHERE a IN ('ae', concat(_utf8mb4 x'c2ad', 'b'), 'ss');
+a
+æ
+b
+ß
+EXPLAIN
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae'), 'ss');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	NULL	range	a	a	7	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where (`test`.`t2`.`a` in (<cache>(concat(_utf8mb4'\xC2\xAD','ae')),'ss'))
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae'), 'ss');
+a
+æ
+ß
+EXPLAIN
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae', _utf8mb4 x'c2ad'), 'ss');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	NULL	range	a	a	7	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where (`test`.`t2`.`a` in (<cache>(concat(_utf8mb4'\xC2\xAD','ae',_utf8mb4'\xC2\xAD')),'ss'))
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae', _utf8mb4 x'c2ad'), 'ss');
+a
+æ
+ß
+EXPLAIN
+SELECT * FROM t2 WHERE a = 'ae' OR a = concat(_utf8mb4 x'c2ad', 'b') OR a = 'ss';
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	NULL	range	a	a	7	NULL	3	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where ((`test`.`t2`.`a` = 'ae') or (`test`.`t2`.`a` = <cache>(concat(_utf8mb4'\xC2\xAD','b'))) or (`test`.`t2`.`a` = 'ss'))
+SELECT * FROM t2 WHERE a = 'ae' OR a = concat(_utf8mb4 x'c2ad', 'b') OR a = 'ss';
+a
+æ
+b
+ß
+# The plan is unstable in this case, however it always uses an index, and results are consistent.
+EXPLAIN
+SELECT * FROM t2 WHERE a IN ('ae', concat(repeat(_utf8mb4 x'c2ad', 2), 'b', repeat(_utf8mb4 x'c2ad', 2)));
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	NULL	X	a	a	7	NULL	X	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where (`test`.`t2`.`a` in ('ae',<cache>(concat(repeat(_utf8mb4'\xC2\xAD',2),'b',repeat(_utf8mb4'\xC2\xAD',2)))))
+# Adding handler statistics to show that execution is also consistent.
+FLUSH STATUS;
+SELECT * FROM t2 WHERE a IN ('ae', concat(repeat(_utf8mb4 x'c2ad', 2), 'b', repeat(_utf8mb4 x'c2ad', 2)));
+a
+æ
+SHOW STATUS LIKE 'Handler_read_%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	2
+Handler_read_last	0
+Handler_read_next	1
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_next	0
+CREATE TABLE t3 ( a VARCHAR(768), KEY(a)) CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
+INSERT INTO t3 VALUES( repeat('æ', 767) ), ( repeat('æ', 768) );
+ANALYZE TABLE t3;
+Table	Op	Msg_type	Msg_text
+test.t3	analyze	status	OK
+EXPLAIN
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('æ', 767) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t3	NULL	index	a	a	3075	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t3` where (`test`.`t3`.`a` in ('a',<cache>(repeat('æ',767))))
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('æ', 767) );
+1
+1
+EXPLAIN
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 768) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t3	NULL	index	a	a	3075	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t3` where (`test`.`t3`.`a` in ('a',<cache>(repeat('ae',768))))
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 768) );
+1
+1
+EXPLAIN
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 769) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t3	NULL	index	a	a	3075	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t3` where (`test`.`t3`.`a` in ('a',<cache>(repeat('ae',769))))
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 769) );
+1
+CREATE TABLE t4 ( a VARCHAR(100), KEY(a(50))) CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
+INSERT INTO t4 VALUES ( repeat('æ', 98) ), ( repeat('æ', 99) ), ( repeat('æ', 100) );
+INSERT INTO t4 VALUES ( concat(repeat( 'a', 50 ), repeat( 'æ', 50 )) );
+ANALYZE TABLE t4;
+Table	Op	Msg_type	Msg_text
+test.t4	analyze	status	OK
+EXPLAIN
+SELECT 1 FROM t4 WHERE a IN ( 'a', repeat('æ', 98) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t4	NULL	range	a	a	203	NULL	4	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t4` where (`test`.`t4`.`a` in ('a',<cache>(repeat('æ',98))))
+SELECT 1 FROM t4 WHERE a IN ( 'a', repeat('æ', 98) );
+1
+1
+CREATE TABLE t5 ( a VARCHAR(16383), KEY(a(768))) CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
+INSERT INTO t5 VALUES( repeat('æ', 16383) ), ( repeat('æ', 16382) ), ( repeat('æ', 16381) );
+ANALYZE TABLE t5;
+Table	Op	Msg_type	Msg_text
+test.t5	analyze	status	OK
+EXPLAIN
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16381) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t5	NULL	range	a	a	3075	NULL	4	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t5` where (`test`.`t5`.`a` in ('a',<cache>(repeat('æ',16381))))
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16381) );
+1
+1
+EXPLAIN
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16382) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t5	NULL	range	a	a	3075	NULL	4	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t5` where (`test`.`t5`.`a` in ('a',<cache>(repeat('æ',16382))))
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16382) );
+1
+1
+EXPLAIN
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16383) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t5	NULL	range	a	a	3075	NULL	4	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t5` where (`test`.`t5`.`a` in ('a',<cache>(repeat('æ',16383))))
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16383) );
+1
+1
+CREATE TABLE t6 ( a VARCHAR(6),  KEY(a(3)) ) CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
+INSERT INTO t6 VALUES ('aaaaaa'), ('æaaaaa'), ('ææaaaa'), ('æææaaa'), ('ææææaa'), ('æææææa'), ('ææææææ'),
+('😊aaaaa'), ('😊æaaaa'), ('😊😊aaaa'), ('😊😊æaaa'), ('😊😊😊aaa');
+ANALYZE TABLE t6;
+Table	Op	Msg_type	Msg_text
+test.t6	analyze	status	OK
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'aaaaaa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','aaaaaa'))
+SELECT * FROM t6 WHERE a IN ( '', 'aaaaaa' );
+a
+aaaaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'æaaaaa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','æaaaaa'))
+SELECT * FROM t6 WHERE a IN ( '', 'æaaaaa' );
+a
+æaaaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'ææaaaa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','ææaaaa'))
+SELECT * FROM t6 WHERE a IN ( '', 'ææaaaa' );
+a
+ææaaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'æææaaa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	5	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','æææaaa'))
+SELECT * FROM t6 WHERE a IN ( '', 'æææaaa' );
+a
+æææaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'ææææaa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	5	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','ææææaa'))
+SELECT * FROM t6 WHERE a IN ( '', 'ææææaa' );
+a
+ææææaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'æææææa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	5	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','æææææa'))
+SELECT * FROM t6 WHERE a IN ( '', 'æææææa' );
+a
+æææææa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'ææææææ' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	5	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','ææææææ'))
+SELECT * FROM t6 WHERE a IN ( '', 'ææææææ' );
+a
+ææææææ
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊aaaaa');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Warning	1300	Cannot convert string '\xF0\x9F\x98\x8Aaa...' from utf8mb4 to utf8mb3
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','?aaaaa'))
+SELECT * FROM t6 WHERE a IN ( '', '😊aaaaa');
+a
+😊aaaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊æaaaa');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Warning	1300	Cannot convert string '\xF0\x9F\x98\x8A\xC3\xA6...' from utf8mb4 to utf8mb3
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','?æaaaa'))
+SELECT * FROM t6 WHERE a IN ( '', '😊æaaaa');
+a
+😊æaaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊😊aaaa');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Warning	1300	Cannot convert string '\xF0\x9F\x98\x8A\xF0\x9F...' from utf8mb4 to utf8mb3
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','??aaaa'))
+SELECT * FROM t6 WHERE a IN ( '', '😊😊aaaa');
+a
+😊😊aaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊😊æaaa');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Warning	1300	Cannot convert string '\xF0\x9F\x98\x8A\xF0\x9F...' from utf8mb4 to utf8mb3
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','??æaaa'))
+SELECT * FROM t6 WHERE a IN ( '', '😊😊😊aaa');
+a
+😊😊😊aaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	7	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('aaaaaa','æaaaaa','ææaaaa','æææaaa','ææææaa','æææææa','ææææææ'))
+SELECT * FROM t6 WHERE a IN ('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ');
+a
+aaaaaa
+æaaaaa
+ææaaaa
+æææaaa
+ææææaa
+æææææa
+ææææææ
+EXPLAIN
+SELECT * FROM t6 WHERE a IN
+('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ',
+'😊aaaaa', '😊æaaaa', '😊😊aaaa', '😊😊æaaa', '😊😊😊aaa');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	ALL	a	NULL	NULL	NULL	12	100.00	Using where
+Warnings:
+Warning	1300	Cannot convert string '\xF0\x9F\x98\x8Aaa...' from utf8mb4 to utf8mb3
+Warning	1300	Cannot convert string '\xF0\x9F\x98\x8A\xC3\xA6...' from utf8mb4 to utf8mb3
+Warning	1300	Cannot convert string '\xF0\x9F\x98\x8A\xF0\x9F...' from utf8mb4 to utf8mb3
+Warning	1300	Cannot convert string '\xF0\x9F\x98\x8A\xF0\x9F...' from utf8mb4 to utf8mb3
+Warning	1300	Cannot convert string '\xF0\x9F\x98\x8A\xF0\x9F...' from utf8mb4 to utf8mb3
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('aaaaaa','æaaaaa','ææaaaa','æææaaa','ææææaa','æææææa','ææææææ','?aaaaa','?æaaaa','??aaaa','??æaaa','???aaa'))
+SELECT * FROM t6 WHERE a IN
+('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ',
+'😊aaaaa', '😊æaaaa', '😊😊aaaa', '😊😊æaaa', '😊😊😊aaa');
+a
+aaaaaa
+æaaaaa
+ææaaaa
+æææaaa
+ææææaa
+æææææa
+ææææææ
+😊aaaaa
+😊æaaaa
+😊😊aaaa
+😊😊æaaa
+😊😊😊aaa
+DROP TABLE t1, t2, t3, t4, t5, t6;
+CREATE TABLE t1 ( pk VARCHAR(16) NOT NULL PRIMARY KEY ) CHARSET=utf16 COLLATE=utf16_unicode_520_ci;
+INSERT INTO t1 VALUES ('abc'), ('def'), ('ghi'), ('jkl'), ('mno');
+ANALYZE TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	analyze	status	OK
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	NULL	index	PRIMARY	PRIMARY	66	NULL	5	60.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`pk` AS `pk` from `test`.`t1` where (`test`.`t1`.`pk` in ('abc','this_value_is_>16','def'))
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+pk
+abc
+def
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	NULL	index	PRIMARY	PRIMARY	66	NULL	5	60.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`pk` AS `pk` from `test`.`t1` where (`test`.`t1`.`pk` in ('abc','this_value_is_>16','def'))
+SELECT * FROM t1 WHERE pk IN ('abc', 'this_value_is_>16', 'def');
+pk
+abc
+def
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	no matching row in const table
+Warnings:
+Note	1003	/* select#1 */ select NULL AS `pk` from `test`.`t1` where (NULL = 'this_value_is_>16')
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16');
+pk
+EXPLAIN
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16', 'and_so_is_this_one');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	NULL	range	PRIMARY	PRIMARY	66	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`pk` AS `pk` from `test`.`t1` where (`test`.`t1`.`pk` in ('this_value_is_>16','and_so_is_this_one'))
+SELECT * FROM t1 WHERE pk IN ('this_value_is_>16', 'and_so_is_this_one');
+pk
+CREATE TABLE t2 ( a VARCHAR(1), KEY (a) ) CHARSET=utf16 COLLATE=utf16_unicode_520_ci;
+INSERT INTO t2 VALUES (NULL), ('a'), ('b'), ('æ'), ('ß'), ('s');
+INSERT INTO t2 SELECT 'x' FROM t2;
+INSERT INTO t2 SELECT 'x' FROM t2;
+ANALYZE TABLE t2;
+Table	Op	Msg_type	Msg_text
+test.t2	analyze	status	OK
+# Strings containing soft hyphen (U+00AD) will not match for UTF-16
+EXPLAIN
+SELECT * FROM t2 WHERE a IN ('ae', concat(_utf8mb4 x'c2ad', 'b'), 'ss');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	NULL	range	a	a	7	NULL	3	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where (`test`.`t2`.`a` in ('ae','­b','ss'))
+SELECT * FROM t2 WHERE a IN ('ae', concat(_utf8mb4 x'c2ad', 'b'), 'ss');
+a
+æ
+ß
+EXPLAIN
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae'), 'ss');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	NULL	range	a	a	7	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where (`test`.`t2`.`a` in ('­ae','ss'))
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae'), 'ss');
+a
+ß
+EXPLAIN
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae', _utf8mb4 x'c2ad'), 'ss');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	NULL	range	a	a	7	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where (`test`.`t2`.`a` in ('­ae­','ss'))
+SELECT * FROM t2 WHERE a IN (concat(_utf8mb4 x'c2ad', 'ae', _utf8mb4 x'c2ad'), 'ss');
+a
+ß
+EXPLAIN
+SELECT * FROM t2 WHERE a = 'ae' OR a = concat(_utf8mb4 x'c2ad', 'b') OR a = 'ss';
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	NULL	range	a	a	7	NULL	3	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where ((`test`.`t2`.`a` = 'ae') or (`test`.`t2`.`a` = '­b') or (`test`.`t2`.`a` = 'ss'))
+SELECT * FROM t2 WHERE a = 'ae' OR a = concat(_utf8mb4 x'c2ad', 'b') OR a = 'ss';
+a
+æ
+ß
+# The plan is unstable in this case, however it always uses an index, and results are consistent.
+EXPLAIN
+SELECT * FROM t2 WHERE a IN ('ae', concat(repeat(_utf8mb4 x'c2ad', 2), 'b', repeat(_utf8mb4 x'c2ad', 2)));
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t2	NULL	X	a	a	7	NULL	X	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where (`test`.`t2`.`a` in ('ae','­­b­­'))
+# Adding handler statistics to show that execution is also consistent.
+FLUSH STATUS;
+SELECT * FROM t2 WHERE a IN ('ae', concat(repeat(_utf8mb4 x'c2ad', 2), 'b', repeat(_utf8mb4 x'c2ad', 2)));
+a
+æ
+SHOW STATUS LIKE 'Handler_read_%';
+Variable_name	Value
+Handler_read_first	0
+Handler_read_key	2
+Handler_read_last	0
+Handler_read_next	1
+Handler_read_prev	0
+Handler_read_rnd	0
+Handler_read_rnd_next	0
+CREATE TABLE t3 ( a VARCHAR(768), KEY(a)) CHARSET=utf16 COLLATE=utf16_unicode_520_ci;
+INSERT INTO t3 VALUES( repeat('æ', 767) ), ( repeat('æ', 768) );
+ANALYZE TABLE t3;
+Table	Op	Msg_type	Msg_text
+test.t3	analyze	status	OK
+EXPLAIN
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('æ', 767) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t3	NULL	index	a	a	3075	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t3` where (`test`.`t3`.`a` in ('a','æ...'))
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('æ', 767) );
+1
+1
+EXPLAIN
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 768) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t3	NULL	index	a	a	3075	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t3` where (`test`.`t3`.`a` in ('a','ae..'))
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 768) );
+1
+1
+EXPLAIN
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 769) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t3	NULL	index	a	a	3075	NULL	2	100.00	Using where; Using index
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t3` where (`test`.`t3`.`a` in ('a','ae...'))
+SELECT 1 FROM t3 WHERE a IN ( 'a', repeat('ae', 769) );
+1
+CREATE TABLE t4 ( a VARCHAR(100), KEY(a(50))) CHARSET=utf16 COLLATE=utf16_unicode_520_ci;
+INSERT INTO t4 VALUES ( repeat('æ', 98) ), ( repeat('æ', 99) ), ( repeat('æ', 100) );
+INSERT INTO t4 VALUES ( concat(repeat( 'a', 50 ), repeat( 'æ', 50 )) );
+ANALYZE TABLE t4;
+Table	Op	Msg_type	Msg_text
+test.t4	analyze	status	OK
+EXPLAIN
+SELECT 1 FROM t4 WHERE a IN ( 'a', repeat('æ', 98) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t4	NULL	range	a	a	203	NULL	4	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t4` where (`test`.`t4`.`a` in ('a','æ...'))
+SELECT 1 FROM t4 WHERE a IN ( 'a', repeat('æ', 98) );
+1
+1
+CREATE TABLE t5 ( a VARCHAR(16383), KEY(a(768))) CHARSET=utf16 COLLATE=utf16_unicode_520_ci;
+INSERT INTO t5 VALUES( repeat('æ', 16383) ), ( repeat('æ', 16382) ), ( repeat('æ', 16381) );
+ANALYZE TABLE t5;
+Table	Op	Msg_type	Msg_text
+test.t5	analyze	status	OK
+EXPLAIN
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16381) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t5	NULL	range	a	a	3075	NULL	4	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t5` where (`test`.`t5`.`a` in ('a','æ...'))
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16381) );
+1
+1
+EXPLAIN
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16382) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t5	NULL	range	a	a	3075	NULL	4	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t5` where (`test`.`t5`.`a` in ('a','æ...'))
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16382) );
+1
+1
+EXPLAIN
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16383) );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t5	NULL	range	a	a	3075	NULL	4	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select 1 AS `1` from `test`.`t5` where (`test`.`t5`.`a` in ('a','æ...'))
+SELECT 1 FROM t5 WHERE a IN ( 'a', repeat('æ', 16383) );
+1
+1
+CREATE TABLE t6 ( a VARCHAR(6),  KEY(a(3)) ) CHARSET=utf16 COLLATE=utf16_unicode_520_ci;
+INSERT INTO t6 VALUES ('aaaaaa'), ('æaaaaa'), ('ææaaaa'), ('æææaaa'), ('ææææaa'), ('æææææa'), ('ææææææ'),
+('😊aaaaa'), ('😊æaaaa'), ('😊😊aaaa'), ('😊😊æaaa'), ('😊😊😊aaa');
+ANALYZE TABLE t6;
+Table	Op	Msg_type	Msg_text
+test.t6	analyze	status	OK
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'aaaaaa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','aaaaaa'))
+SELECT * FROM t6 WHERE a IN ( '', 'aaaaaa' );
+a
+aaaaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'æaaaaa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','æaaaaa'))
+SELECT * FROM t6 WHERE a IN ( '', 'æaaaaa' );
+a
+æaaaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'ææaaaa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','ææaaaa'))
+SELECT * FROM t6 WHERE a IN ( '', 'ææaaaa' );
+a
+ææaaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'æææaaa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	5	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','æææaaa'))
+SELECT * FROM t6 WHERE a IN ( '', 'æææaaa' );
+a
+æææaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'ææææaa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	5	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','ææææaa'))
+SELECT * FROM t6 WHERE a IN ( '', 'ææææaa' );
+a
+ææææaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'æææææa' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	5	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','æææææa'))
+SELECT * FROM t6 WHERE a IN ( '', 'æææææa' );
+a
+æææææa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', 'ææææææ' );
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	5	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','ææææææ'))
+SELECT * FROM t6 WHERE a IN ( '', 'ææææææ' );
+a
+ææææææ
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊aaaaa');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Warning	1300	Cannot convert string '\xD8\x3D\xDE\x0A\x00\x61...' from utf16 to utf8mb3
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','?aaaaa'))
+SELECT * FROM t6 WHERE a IN ( '', '😊aaaaa');
+a
+😊aaaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊æaaaa');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Warning	1300	Cannot convert string '\xD8\x3D\xDE\x0A\x00\xE6...' from utf16 to utf8mb3
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','?æaaaa'))
+SELECT * FROM t6 WHERE a IN ( '', '😊æaaaa');
+a
+😊æaaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊😊aaaa');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Warning	1300	Cannot convert string '\xD8\x3D\xDE\x0A\xD8\x3D...' from utf16 to utf8mb3
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','??aaaa'))
+SELECT * FROM t6 WHERE a IN ( '', '😊😊aaaa');
+a
+😊😊aaaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ( '', '😊😊æaaa');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	2	100.00	Using where
+Warnings:
+Warning	1300	Cannot convert string '\xD8\x3D\xDE\x0A\xD8\x3D...' from utf16 to utf8mb3
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('','??æaaa'))
+SELECT * FROM t6 WHERE a IN ( '', '😊😊😊aaa');
+a
+😊😊😊aaa
+EXPLAIN
+SELECT * FROM t6 WHERE a IN ('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	range	a	a	15	NULL	7	100.00	Using where
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('aaaaaa','æaaaaa','ææaaaa','æææaaa','ææææaa','æææææa','ææææææ'))
+SELECT * FROM t6 WHERE a IN ('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ');
+a
+aaaaaa
+æaaaaa
+ææaaaa
+æææaaa
+ææææaa
+æææææa
+ææææææ
+EXPLAIN
+SELECT * FROM t6 WHERE a IN
+('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ',
+'😊aaaaa', '😊æaaaa', '😊😊aaaa', '😊😊æaaa', '😊😊😊aaa');
+id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t6	NULL	ALL	a	NULL	NULL	NULL	12	100.00	Using where
+Warnings:
+Warning	1300	Cannot convert string '\xD8\x3D\xDE\x0A\x00\x61...' from utf16 to utf8mb3
+Warning	1300	Cannot convert string '\xD8\x3D\xDE\x0A\x00\xE6...' from utf16 to utf8mb3
+Warning	1300	Cannot convert string '\xD8\x3D\xDE\x0A\xD8\x3D...' from utf16 to utf8mb3
+Warning	1300	Cannot convert string '\xD8\x3D\xDE\x0A\xD8\x3D...' from utf16 to utf8mb3
+Warning	1300	Cannot convert string '\xD8\x3D\xDE\x0A\xD8\x3D...' from utf16 to utf8mb3
+Note	1003	/* select#1 */ select `test`.`t6`.`a` AS `a` from `test`.`t6` where (`test`.`t6`.`a` in ('aaaaaa','æaaaaa','ææaaaa','æææaaa','ææææaa','æææææa','ææææææ','?aaaaa','?æaaaa','??aaaa','??æaaa','???aaa'))
+SELECT * FROM t6 WHERE a IN
+('aaaaaa', 'æaaaaa', 'ææaaaa', 'æææaaa', 'ææææaa', 'æææææa', 'ææææææ',
+'😊aaaaa', '😊æaaaa', '😊😊aaaa', '😊😊æaaa', '😊😊😊aaa');
+a
+aaaaaa
+æaaaaa
+ææaaaa
+æææaaa
+ææææaa
+æææææa
+ææææææ
+😊aaaaa
+😊æaaaa
+😊😊aaaa
+😊😊æaaa
+😊😊😊aaa
+DROP TABLE t1, t2, t3, t4, t5, t6;
+CREATE TABLE t1 (
+a VARCHAR(3),
+KEY(a)
+);
+INSERT INTO t1 VALUES ('aaa'), ('bbb'), ('ccc');
+CREATE FUNCTION bad_str() RETURNS VARBINARY(10) DETERMINISTIC NO SQL
+BEGIN
+RETURN concat('aaaaaaaaaa', UNHEX('73C080'));  # invalid overlong UTF-8 NUL
+END //
+SELECT * FROM t1 WHERE a < bad_str();
+ERROR 22001: Data too long for column 'bad_str' at row 1
+DROP FUNCTION bad_str;
+DROP TABLE t1;
diff --git a/mysql-test/t/type_varchar.test b/mysql-test/t/type_varchar.test
index 9a52ae98ab76..49b2b5af5229 100644
--- a/mysql-test/t/type_varchar.test
+++ b/mysql-test/t/type_varchar.test
@@ -178,3 +178,37 @@ CREATE TABLE t1 (a CHAR(16));
 INSERT INTO t1 VALUES ('5'), ('s'), ('');
 SELECT 5 = a FROM t1;
 DROP TABLE t1;
+--echo #
+--echo # Bug#118009: SELECT query on primary key column deteriorates to full
+--echo #             table scan when filter involves too long string
+--echo #
+
+--let charset=utf8mb4
+--let collation=utf8mb4_0900_ai_ci
+--source include/oversized_varchar_key.inc
+
+--let charset=utf16
+--let collation=utf16_unicode_520_ci
+--source include/oversized_varchar_key.inc
+
+CREATE TABLE t1 (
+    a VARCHAR(3),
+    KEY(a)
+);
+
+INSERT INTO t1 VALUES ('aaa'), ('bbb'), ('ccc');
+
+DELIMITER //;
+
+CREATE FUNCTION bad_str() RETURNS VARBINARY(10) DETERMINISTIC NO SQL
+BEGIN
+  RETURN concat('aaaaaaaaaa', UNHEX('73C080'));  # invalid overlong UTF-8 NUL
+END //
+
+DELIMITER ;//
+
+--error ER_DATA_TOO_LONG
+SELECT * FROM t1 WHERE a < bad_str();
+
+DROP FUNCTION bad_str;
+DROP TABLE t1;
diff --git a/sql/range_optimizer/range_analysis.cc b/sql/range_optimizer/range_analysis.cc
index 624cd0722683..8d3b6b86f7b3 100644
--- a/sql/range_optimizer/range_analysis.cc
+++ b/sql/range_optimizer/range_analysis.cc
@@ -24,6 +24,7 @@
 #include <assert.h>
 #include <string.h>
 #include <sys/types.h>
+#include <algorithm>
 
 #include "field_types.h"
 #include "memory_debugging.h"
@@ -70,6 +71,8 @@
 #include "sql_string.h"
 #include "template_utils.h"
 
+bool is_prefix_index(TABLE *table, uint idx);
+
 /*
   A null_sel_tree is used in get_func_mm_tree_from_in_predicate to pass
   as an argument to tree_or. It is used only to influence the return
@@ -1391,6 +1394,77 @@ static bool save_value_and_handle_conversion(
   return true;
 }
 
+/**
+  Creates a search key for a value that may be larger than the index it
+  searches.
+
+  The code inside save_value_and_handle_conversion() cannot create a
+  search key if the value is larger than the declared size of the index. This
+  happens because the code instantiating search keys is tied to the Field
+  class, which doesn't allocate room for keys larger than the index. For unicode
+  strings, there is no limit for how large the search key can be. For instance,
+  multiple character can match a single character, for example "ae" can match
+  "æ" in many collations. A more contrived example is that any number of SMALL
+  HYPHEN (U+00AD) can be in the search string as they are ignored in string
+  matching.
+
+  If any one search key cannot be created, the optimizer falls back
+  to table scan. This function act as a second chance, allocating as large a
+  buffer as needed and creates the search key there instead. Since the scenario
+  can only happen for strings, the procedure is much simpler than for arbitrary
+  types.
+
+  @param value      The search value.
+  @param field      The column the value is being compared against.
+  @param key_part   The index column for the index being considered.
+  @param alloc      MEM_ROOT used to allocate the key buffer from.
+
+  @return Pointer to the key buffer, or nullptr if the search key could not be
+          created.
+*/
+static uchar *make_oversized_search_key(Item *value, const Field *field,
+                                        const KEY_PART *key_part,
+                                        MEM_ROOT *alloc) {
+  const size_t null_bytes = field->is_nullable() ? 1 : 0;
+  const size_t size_bytes = 2;
+  String buf;
+  auto *str_value = value->val_str(&buf);
+  if (str_value == nullptr) return nullptr;
+
+  const CHARSET_INFO *cs = field->charset();
+  size_t key_len =
+      cs->coll->strnxfrmlen(cs, str_value->length() * cs->mbmaxlen);
+  auto *key_buf =
+      static_cast<char *>(alloc->Alloc(null_bytes + size_bytes + key_len));
+  if (key_buf == nullptr) return nullptr;
+
+  int nchars = is_prefix_index(field->table, key_part->key)
+                   ? key_part->length / cs->mbmaxlen
+                   : key_len / cs->mbmaxlen;
+
+  const char *well_formed_error_pos;
+  const char *cannot_convert_error_pos;
+  const char *from_end_pos;
+
+  auto num_bytes_in_key = well_formed_copy_nchars(
+      cs, key_buf + null_bytes + size_bytes, str_value->length(), cs,
+      str_value->ptr(), str_value->length(), nchars, &well_formed_error_pos,
+      &cannot_convert_error_pos, &from_end_pos);
+
+  if (well_formed_error_pos != nullptr || cannot_convert_error_pos != nullptr) {
+    assert(false);
+    return nullptr;
+  }
+
+  if (field->is_nullable()) {
+    key_buf[0] = char{field->is_real_null()};
+  }
+
+  int2store(key_buf + null_bytes, num_bytes_in_key);
+
+  return reinterpret_cast<uchar *>(key_buf);
+}
+
 static SEL_ROOT *get_mm_leaf(THD *thd, RANGE_OPT_PARAM *param, Item *cond_func,
                              Field *field, KEY_PART *key_part,
                              Item_func::Functype type, Item *value,
@@ -1399,7 +1473,7 @@ static SEL_ROOT *get_mm_leaf(THD *thd, RANGE_OPT_PARAM *param, Item *cond_func,
   bool optimize_range;
   SEL_ROOT *tree = nullptr;
   MEM_ROOT *const alloc = param->temp_mem_root;
-  uchar *str;
+  uchar *str{nullptr};
   const char *impossible_cond_cause = nullptr;
   DBUG_TRACE;
 
@@ -1583,6 +1657,17 @@ static SEL_ROOT *get_mm_leaf(THD *thd, RANGE_OPT_PARAM *param, Item *cond_func,
         &tree, value, type, field, &impossible_cond_cause, alloc,
         param->query_block, inexact);
 
+    if (always_true_or_false && *inexact && is_string_type(field->type()) &&
+        (!is_prefix_index(field->table, key_part->key) ||
+         type == Item_func::EQ_FUNC)) {
+      // The handler cannot currently handle non-equality ranges on prefix
+      // indexes.
+      str = make_oversized_search_key(value, field, key_part, alloc);
+      if (str != nullptr) {
+        always_true_or_false = false;
+      }
+    }
+
     if (field->type() == MYSQL_TYPE_GEOMETRY &&
         save_geom_type != Field::GEOM_GEOMETRY) {
       down_cast<Field_geom *>(field)->geom_type = save_geom_type;
@@ -1601,12 +1686,15 @@ static SEL_ROOT *get_mm_leaf(THD *thd, RANGE_OPT_PARAM *param, Item *cond_func,
     goto end;
   }
 
-  str = (uchar *)alloc->Alloc(key_part->store_length + 1);
-  if (!str) goto end;
-  if (field->is_nullable())
-    *str = (uchar)field->is_real_null();  // Set to 1 if null
-  field->get_key_image(str + null_bytes, key_part->length,
-                       key_part->image_type);
+  if (str == nullptr) {
+    // Create the search key if we didn't already.
+    str = (uchar *)alloc->Alloc(key_part->store_length + 1);
+    if (!str) goto end;
+    if (field->is_nullable())
+      *str = (uchar)field->is_real_null();  // Set to 1 if null
+    field->get_key_image(str + null_bytes, key_part->length,
+                         key_part->image_type);
+  }
   SEL_ARG *root;
   root =
       new (alloc) SEL_ARG(field, str, str, !(key_part->flag & HA_REVERSE_SORT));