diff --git a/mysql-test/main/rowid_filter_innodb.result b/mysql-test/main/rowid_filter_innodb.result
index 276b57a106c..24b80881c6e 100644
--- a/mysql-test/main/rowid_filter_innodb.result
+++ b/mysql-test/main/rowid_filter_innodb.result
@@ -2917,7 +2917,7 @@ ORDER BY timestamp DESC;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	ixEventWhoisDomainDomain,ixEventWhoisDomainTimestamp	NULL	NULL	NULL	60	22.22	Using where; Using filesort
 Warnings:
-Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`domain` AS `domain`,`test`.`t1`.`registrant_name` AS `registrant_name`,`test`.`t1`.`registrant_organization` AS `registrant_organization`,`test`.`t1`.`registrant_street1` AS `registrant_street1`,`test`.`t1`.`registrant_street2` AS `registrant_street2`,`test`.`t1`.`registrant_street3` AS `registrant_street3`,`test`.`t1`.`registrant_street4` AS `registrant_street4`,`test`.`t1`.`registrant_street5` AS `registrant_street5`,`test`.`t1`.`registrant_city` AS `registrant_city`,`test`.`t1`.`registrant_postal_code` AS `registrant_postal_code`,`test`.`t1`.`registrant_country` AS `registrant_country`,`test`.`t1`.`registrant_email` AS `registrant_email`,`test`.`t1`.`registrant_telephone` AS `registrant_telephone`,`test`.`t1`.`administrative_name` AS `administrative_name`,`test`.`t1`.`administrative_organization` AS `administrative_organization`,`test`.`t1`.`administrative_street1` AS `administrative_street1`,`test`.`t1`.`administrative_street2` AS `administrative_street2`,`test`.`t1`.`administrative_street3` AS `administrative_street3`,`test`.`t1`.`administrative_street4` AS `administrative_street4`,`test`.`t1`.`administrative_street5` AS `administrative_street5`,`test`.`t1`.`administrative_city` AS `administrative_city`,`test`.`t1`.`administrative_postal_code` AS `administrative_postal_code`,`test`.`t1`.`administrative_country` AS `administrative_country`,`test`.`t1`.`administrative_email` AS `administrative_email`,`test`.`t1`.`administrative_telephone` AS `administrative_telephone`,`test`.`t1`.`technical_name` AS `technical_name`,`test`.`t1`.`technical_organization` AS `technical_organization`,`test`.`t1`.`technical_street1` AS `technical_street1`,`test`.`t1`.`technical_street2` AS `technical_street2`,`test`.`t1`.`technical_street3` AS `technical_street3`,`test`.`t1`.`technical_street4` AS `technical_street4`,`test`.`t1`.`technical_street5` AS `technical_street5`,`test`.`t1`.`technical_city` AS `technical_city`,`test`.`t1`.`technical_postal_code` AS `technical_postal_code`,`test`.`t1`.`technical_country` AS `technical_country`,`test`.`t1`.`technical_email` AS `technical_email`,`test`.`t1`.`technical_telephone` AS `technical_telephone`,`test`.`t1`.`json` AS `json`,`test`.`t1`.`timestamp` AS `timestamp` from `test`.`t1` where `test`.`t1`.`domain` = 'www.mailhost.i-dev.fr' and `test`.`t1`.`timestamp` >= <cache>('2017-01-30 08:24:51' + interval -1 month) order by `test`.`t1`.`timestamp` desc
+Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`domain` AS `domain`,`test`.`t1`.`registrant_name` AS `registrant_name`,`test`.`t1`.`registrant_organization` AS `registrant_organization`,`test`.`t1`.`registrant_street1` AS `registrant_street1`,`test`.`t1`.`registrant_street2` AS `registrant_street2`,`test`.`t1`.`registrant_street3` AS `registrant_street3`,`test`.`t1`.`registrant_street4` AS `registrant_street4`,`test`.`t1`.`registrant_street5` AS `registrant_street5`,`test`.`t1`.`registrant_city` AS `registrant_city`,`test`.`t1`.`registrant_postal_code` AS `registrant_postal_code`,`test`.`t1`.`registrant_country` AS `registrant_country`,`test`.`t1`.`registrant_email` AS `registrant_email`,`test`.`t1`.`registrant_telephone` AS `registrant_telephone`,`test`.`t1`.`administrative_name` AS `administrative_name`,`test`.`t1`.`administrative_organization` AS `administrative_organization`,`test`.`t1`.`administrative_street1` AS `administrative_street1`,`test`.`t1`.`administrative_street2` AS `administrative_street2`,`test`.`t1`.`administrative_street3` AS `administrative_street3`,`test`.`t1`.`administrative_street4` AS `administrative_street4`,`test`.`t1`.`administrative_street5` AS `administrative_street5`,`test`.`t1`.`administrative_city` AS `administrative_city`,`test`.`t1`.`administrative_postal_code` AS `administrative_postal_code`,`test`.`t1`.`administrative_country` AS `administrative_country`,`test`.`t1`.`administrative_email` AS `administrative_email`,`test`.`t1`.`administrative_telephone` AS `administrative_telephone`,`test`.`t1`.`technical_name` AS `technical_name`,`test`.`t1`.`technical_organization` AS `technical_organization`,`test`.`t1`.`technical_street1` AS `technical_street1`,`test`.`t1`.`technical_street2` AS `technical_street2`,`test`.`t1`.`technical_street3` AS `technical_street3`,`test`.`t1`.`technical_street4` AS `technical_street4`,`test`.`t1`.`technical_street5` AS `technical_street5`,`test`.`t1`.`technical_city` AS `technical_city`,`test`.`t1`.`technical_postal_code` AS `technical_postal_code`,`test`.`t1`.`technical_country` AS `technical_country`,`test`.`t1`.`technical_email` AS `technical_email`,`test`.`t1`.`technical_telephone` AS `technical_telephone`,`test`.`t1`.`json` AS `json`,`test`.`t1`.`timestamp` AS `timestamp` from `test`.`t1` where `test`.`t1`.`domain` = 'www.mailhost.i-dev.fr' and `test`.`t1`.`timestamp` >= TIMESTAMP/*WITH LOCAL TIME ZONE*/'2016-12-30 08:24:51' order by `test`.`t1`.`timestamp` desc
 SET optimizer_switch=@save_optimizer_switch;
 DROP TABLE t1;
 #
diff --git a/mysql-test/main/timezone2.result b/mysql-test/main/timezone2.result
index 787552d9159..382ed447c92 100644
--- a/mysql-test/main/timezone2.result
+++ b/mysql-test/main/timezone2.result
@@ -678,3 +678,188 @@ SELECT a, UNIX_TIMESTAMP(a) FROM t1 WHERE a >= ALL (SELECT * FROM t1);
 a	UNIX_TIMESTAMP(a)
 2010-10-31 02:25:25	1288481125
 DROP TABLE t1;
+#
+# MDEV-32148 Inefficient WHERE timestamp_column=datetime_expr
+#
+#
+# Testing a DST change (fall back)
+#
+SET time_zone='Europe/Moscow';
+SET @first_second_after_dst_fall_back=1288479600;
+CREATE TABLE t1 (a TIMESTAMP NULL);
+INSERT INTO t1 VALUES ('2001-01-01 10:20:30'),('2001-01-01 10:20:31');
+#
+# Optimized (more than 24 hours before the DST fall back)
+#
+SET timestamp=@first_second_after_dst_fall_back-24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+1288393199	2010-10-30 02:59:59
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2010-10-30 02:59:59'
+#
+# Not optimized (24 hours before the DST fall back)
+#
+SET timestamp=@first_second_after_dst_fall_back-24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+1288393200	2010-10-30 03:00:00
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = <cache>(current_timestamp())
+#
+# Not optimized (less than 24 hours after the DST fall back)
+#
+SET timestamp=@first_second_after_dst_fall_back+24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+1288565999	2010-11-01 01:59:59
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = <cache>(current_timestamp())
+#
+# Optimized (24 hours after the DST fall back)
+#
+SET timestamp=@first_second_after_dst_fall_back+24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+1288566000	2010-11-01 02:00:00
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2010-11-01 02:00:00'
+DROP TABLE t1;
+SET time_zone=DEFAULT;
+#
+# Testing a DST change (spring forward)
+#
+SET time_zone='Europe/Moscow';
+SET @first_second_after_dst_spring_forward=1301180400;
+CREATE TABLE t1 (a TIMESTAMP NULL);
+INSERT INTO t1 VALUES ('2001-01-01 10:20:30'),('2001-01-01 10:20:31');
+#
+# Optimized (more than 24 hours before the DST sprint forward)
+#
+SET timestamp=@first_second_after_dst_spring_forward-24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+1301093999	2011-03-26 01:59:59
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2011-03-26 01:59:59'
+#
+# Not optimized (24 hours before the DST sprint forward)
+#
+SET timestamp=@first_second_after_dst_spring_forward-24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+1301094000	2011-03-26 02:00:00
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = <cache>(current_timestamp())
+#
+# Not optimized (less than 24 hours after the DST sprint forward)
+#
+SET timestamp=@first_second_after_dst_spring_forward+24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+1301266799	2011-03-28 02:59:59
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = <cache>(current_timestamp())
+#
+# Optimized (24 hours after the DST sprint forward)
+#
+SET timestamp=@first_second_after_dst_spring_forward+24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+1301266800	2011-03-28 03:00:00
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2011-03-28 03:00:00'
+DROP TABLE t1;
+#
+# Testing a leap second
+#
+SET time_zone='leap/Europe/Moscow';
+SET @leap_second=362793609;
+/*The 60th leap second*/
+CREATE TABLE t1 (a TIMESTAMP);
+SET timestamp=@leap_second-1;
+INSERT INTO t1 VALUES (NOW());
+SET timestamp=@leap_second;
+INSERT INTO t1 VALUES (NOW());
+SET timestamp=@leap_second+1;
+INSERT INTO t1 VALUES (NOW());
+SELECT UNIX_TIMESTAMP(a), a FROM t1 ORDER BY UNIX_TIMESTAMP(a);
+UNIX_TIMESTAMP(a)	a
+362793608	1981-07-01 03:59:59
+362793609	1981-07-01 03:59:59
+362793610	1981-07-01 04:00:00
+INSERT INTO t1 VALUES ('2001-01-01 10:20:30');
+#
+# Optimized (more than 24 hours before the leap second)
+#
+SET timestamp=@leap_second-24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+362707208	1981-06-30 03:59:59
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+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 where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'1981-06-30 03:59:59'
+#
+# Not optimized (24 hours before the leap second)
+#
+SET timestamp=@leap_second-24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+362707209	1981-06-30 04:00:00
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+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 where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = <cache>(current_timestamp())
+#
+# Not optimized (less than 24 hours after the leap second)
+#
+SET timestamp=@leap_second+24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+362880008	1981-07-02 03:59:58
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+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 where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = <cache>(current_timestamp())
+#
+# Not optimized (24 hours after the leap second)
+#
+SET timestamp=@leap_second+24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+UNIX_TIMESTAMP()	NOW()
+362880009	1981-07-02 03:59:59
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+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 where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'1981-07-02 03:59:59'
+DROP TABLE t1;
+SET time_zone=DEFAULT;
diff --git a/mysql-test/main/timezone2.test b/mysql-test/main/timezone2.test
index b5045203903..09be74089ce 100644
--- a/mysql-test/main/timezone2.test
+++ b/mysql-test/main/timezone2.test
@@ -630,3 +630,155 @@ SELECT a, UNIX_TIMESTAMP(a) FROM t1 ORDER BY a;
 SELECT a, UNIX_TIMESTAMP(a) FROM t1 WHERE a <= ALL (SELECT * FROM t1);
 SELECT a, UNIX_TIMESTAMP(a) FROM t1 WHERE a >= ALL (SELECT * FROM t1);
 DROP TABLE t1;
+
+
+--echo #
+--echo # MDEV-32148 Inefficient WHERE timestamp_column=datetime_expr
+--echo #
+
+--echo #
+--echo # Testing a DST change (fall back)
+--echo #
+
+SET time_zone='Europe/Moscow';
+# '2010-10-31 02:59:59' (1288479599)
+# '2010-10-31 02:00:00' (1288479600)
+SET @first_second_after_dst_fall_back=1288479600;
+
+CREATE TABLE t1 (a TIMESTAMP NULL);
+INSERT INTO t1 VALUES ('2001-01-01 10:20:30'),('2001-01-01 10:20:31');
+
+--echo #
+--echo # Optimized (more than 24 hours before the DST fall back)
+--echo #
+
+SET timestamp=@first_second_after_dst_fall_back-24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+--echo #
+--echo # Not optimized (24 hours before the DST fall back)
+--echo #
+
+SET timestamp=@first_second_after_dst_fall_back-24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+--echo #
+--echo # Not optimized (less than 24 hours after the DST fall back)
+--echo #
+
+SET timestamp=@first_second_after_dst_fall_back+24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+--echo #
+--echo # Optimized (24 hours after the DST fall back)
+--echo #
+
+SET timestamp=@first_second_after_dst_fall_back+24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+DROP TABLE t1;
+SET time_zone=DEFAULT;
+
+
+--echo #
+--echo # Testing a DST change (spring forward)
+--echo #
+
+SET time_zone='Europe/Moscow';
+# '2011-03-27 01:59:59' (1301180399)
+# '2011-03-27 03:00:00' (1301180400)
+SET @first_second_after_dst_spring_forward=1301180400;
+
+CREATE TABLE t1 (a TIMESTAMP NULL);
+INSERT INTO t1 VALUES ('2001-01-01 10:20:30'),('2001-01-01 10:20:31');
+
+--echo #
+--echo # Optimized (more than 24 hours before the DST sprint forward)
+--echo #
+
+SET timestamp=@first_second_after_dst_spring_forward-24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+--echo #
+--echo # Not optimized (24 hours before the DST sprint forward)
+--echo #
+
+SET timestamp=@first_second_after_dst_spring_forward-24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+--echo #
+--echo # Not optimized (less than 24 hours after the DST sprint forward)
+--echo #
+
+SET timestamp=@first_second_after_dst_spring_forward+24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+--echo #
+--echo # Optimized (24 hours after the DST sprint forward)
+--echo #
+
+SET timestamp=@first_second_after_dst_spring_forward+24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+DROP TABLE t1;
+
+--echo #
+--echo # Testing a leap second
+--echo #
+
+SET time_zone='leap/Europe/Moscow';
+SET @leap_second=362793609; /*The 60th leap second*/
+
+CREATE TABLE t1 (a TIMESTAMP);
+SET timestamp=@leap_second-1;
+INSERT INTO t1 VALUES (NOW());
+SET timestamp=@leap_second;
+INSERT INTO t1 VALUES (NOW());
+SET timestamp=@leap_second+1;
+INSERT INTO t1 VALUES (NOW());
+SELECT UNIX_TIMESTAMP(a), a FROM t1 ORDER BY UNIX_TIMESTAMP(a);
+INSERT INTO t1 VALUES ('2001-01-01 10:20:30');
+
+--echo #
+--echo # Optimized (more than 24 hours before the leap second)
+--echo #
+
+SET timestamp=@leap_second-24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+--echo #
+--echo # Not optimized (24 hours before the leap second)
+--echo #
+
+SET timestamp=@leap_second-24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+--echo #
+--echo # Not optimized (less than 24 hours after the leap second)
+--echo #
+
+SET timestamp=@leap_second+24*3600-1;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+--echo #
+--echo # Not optimized (24 hours after the leap second)
+--echo #
+
+SET timestamp=@leap_second+24*3600;
+SELECT UNIX_TIMESTAMP(), NOW();
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=now();
+
+DROP TABLE t1;
+
+SET time_zone=DEFAULT;
diff --git a/mysql-test/main/type_timestamp.result b/mysql-test/main/type_timestamp.result
index 78e860661c5..6b1e5bb8284 100644
--- a/mysql-test/main/type_timestamp.result
+++ b/mysql-test/main/type_timestamp.result
@@ -872,13 +872,13 @@ SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=' 2001-01-01 00:00:00';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2001-01-01 00:00:00'
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00'
 EXPLAIN EXTENDED
 SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a=' 2001-01-01 00:00:00';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2001-01-01 00:00:00' and <cache>(octet_length(TIMESTAMP'2001-01-01 00:00:00')) = 19 + rand()
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00' and <cache>(octet_length(TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00')) = 19 + rand()
 EXPLAIN EXTENDED
 SELECT * FROM t1 WHERE LENGTH(a)=30+RAND() AND a=' garbage ';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
@@ -905,13 +905,13 @@ SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=TIMESTAMP'2001-01-01 00:00:00.000000';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2001-01-01 00:00:00.000000'
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00.000000'
 EXPLAIN EXTENDED
 SELECT * FROM t1 WHERE LENGTH(a)=30+RAND() AND a=TIMESTAMP'2001-01-01 00:00:00.000000';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2001-01-01 00:00:00.000000' and <cache>(octet_length(TIMESTAMP'2001-01-01 00:00:00')) = 30 + rand()
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00.000000' and <cache>(octet_length(TIMESTAMP'2001-01-01 00:00:00')) = 30 + rand()
 DROP TABLE t1;
 CREATE TABLE t1 (a TIMESTAMP(6));;
 INSERT INTO t1 VALUES ('2001-01-01 00:00:00.000000'),('2001-01-01 00:00:01.000000');
@@ -930,13 +930,13 @@ SELECT * FROM t1 WHERE LENGTH(a)=26 AND a=TIMESTAMP'2001-01-01 00:00:00.000000';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2001-01-01 00:00:00.000000'
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00.000000'
 EXPLAIN EXTENDED
 SELECT * FROM t1 WHERE LENGTH(a)=40+RAND() AND a=TIMESTAMP'2001-01-01 00:00:00.000000';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2001-01-01 00:00:00.000000' and <cache>(octet_length(TIMESTAMP'2001-01-01 00:00:00.000000')) = 40 + rand()
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00.000000' and <cache>(octet_length(TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00.000000')) = 40 + rand()
 DROP TABLE t1;
 SET timestamp=UNIX_TIMESTAMP('2001-01-01 10:20:30');
 CREATE TABLE t1 (a TIMESTAMP);;
@@ -956,13 +956,13 @@ SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=TIME'00:00:00';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2001-01-01 00:00:00'
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00'
 EXPLAIN EXTENDED
 SELECT * FROM t1 WHERE LENGTH(a)=40+RAND() AND a=TIME'00:00:00';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
-Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2001-01-01 00:00:00' and <cache>(octet_length(TIMESTAMP'2001-01-01 00:00:00')) = 40 + rand()
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00' and <cache>(octet_length(TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00')) = 40 + rand()
 DROP TABLE t1;
 #
 # End of 10.1 tests
@@ -1347,6 +1347,540 @@ SET time_zone=DEFAULT;
 # End of 10.4 tests
 #
 #
+# Start of 10.6 tests
+#
+#
+# MDEV-32148 Inefficient WHERE timestamp_column=datetime_expr
+#
+SET time_zone='+00:00';
+CREATE TABLE t1 (a TIMESTAMP);
+INSERT INTO t1 VALUES ('0000-00-00 00:00:00');
+INSERT INTO t1 VALUES ('2001-01-01 10:20:30'), ('2001-01-01 10:20:31');
+#
+# Comparison predicates: Bad TIMESTAMP values preserve DATETIME comparison
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1001-01-01 10:20:30';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'1001-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2001-01-00 00:00:00';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2001-01-00 00:00:00'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2040-01-01 10:20:30';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2040-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='1001-01-01 10:20:30';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'1001-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-00 00:00:00';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Warning	1292	Incorrect datetime value: '2001-01-00 00:00:00'
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = '2001-01-00 00:00:00'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2040-01-01 10:20:30';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2040-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=10010101102030;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 10010101102030
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010100000000;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 20010100000000
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20400101102030;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 20400101102030
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=10010101102030e0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 10010101102030e0
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010100000000e0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 20010100000000e0
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20400101102030e0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 20400101102030e0
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=10010101102030.0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 10010101102030.0
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010100000000.0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 20010100000000.0
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20400101102030.0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = 20400101102030.0
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=DATE_ADD('2020-01-01 10:20:30', INTERVAL 30 YEAR);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2050-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE COALESCE(NULL, a)=DATE_ADD('2020-01-01 10:20:30', INTERVAL 30 YEAR);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where coalesce(NULL,`test`.`t1`.`a`) = <cache>('2020-01-01 10:20:30' + interval 30 year)
+#
+# Comparison predicates: Good TIMESTAMP values switch to TIMESTAMP comparison
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'0000-00-00 00:00:00';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'0000-00-00 00:00:00'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2001-01-01 10:20:30';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='0000-00-00 00:00:00';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'0000-00-00 00:00:00'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01 10:20:30';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'0000-00-00 00:00:00'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010101102030;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=0e0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'0000-00-00 00:00:00.000000'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010101102030e0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30.000000'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=0.0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'0000-00-00 00:00:00.0'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010101102030.0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30.0'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=DATE_ADD('2001-01-01 10:20:00', INTERVAL 30 SECOND);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE COALESCE(NULL, a)=DATE_ADD('2001-01-01 10:20:00', INTERVAL 30 SECOND);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where coalesce(NULL,`test`.`t1`.`a`) = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30'
+#
+# Corner cases: DATETIME values before the supported optimization range
+# FROM_UNIXTIME(0)..FROM_UNIXTIME(24*3600-1)
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 00:00:00';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'1970-01-01 00:00:00'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 23:59:59';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'1970-01-01 23:59:59'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 23:59:59.999999';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'1970-01-01 23:59:59.999999'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 23:59:59.9999999';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1292	Truncated incorrect DATETIME value: '1970-01-01 23:59:59.9999999'
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'1970-01-01 23:59:59.999999'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=FROM_UNIXTIME(24*3600-1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = <cache>(from_unixtime(24 * 3600 - 1))
+#
+# Corner cases: DATETIME values inside the supported optimization range:
+# FROM_UNIXTIME(24*3600) .. FROM_UNIXTIME(0x7FFFFFFF-24*3600)
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=FROM_UNIXTIME(24*3600);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'1970-01-02 00:00:00'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-02 00:00:00';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'1970-01-02 00:00:00'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2038-01-18 03:14:07';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2038-01-18 03:14:07'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=FROM_UNIXTIME(0x7FFFFFFF-24*3600);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2038-01-18 03:14:07'
+#
+# Corner cases: DATETIME values after the supported optimization range
+# FROM_UNIXTIME(0x7FFFFFFF-24*3600+1) .. FROM_UNIXTIME(0x7FFFFFFF)
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=FROM_UNIXTIME(0x7FFFFFFF-24*3600+1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = <cache>(from_unixtime(0x7fffffff - 24 * 3600 + 1))
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2038-01-18 03:14:08';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2038-01-18 03:14:08'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2038-01-19 03:14:07';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2038-01-19 03:14:07'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=FROM_UNIXTIME(0x7FFFFFFF);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = <cache>(from_unixtime(0x7fffffff))
+#
+# Corner cases: rounding
+#
+SET sql_mode=TIME_ROUND_FRACTIONAL;
+#
+# Not optimized (before the supported range)
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 23:59:59.999999';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'1970-01-01 23:59:59.999999'
+#
+# Optimized
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 23:59:59.9999999';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1292	Truncated incorrect DATETIME value: '1970-01-01 23:59:59.9999999'
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'1970-01-02 00:00:00.000000'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2038-01-18 03:14:07.999999';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2038-01-18 03:14:07.999999'
+#
+# Not optimized (after the supported range)
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2038-01-18 03:14:07.9999999';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1292	Truncated incorrect DATETIME value: '2038-01-18 03:14:07.9999999'
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP'2038-01-18 03:14:08.000000'
+SET sql_mode=DEFAULT;
+#
+# NULLIF: Bad TIMESTAMP values preserve DATETIME comparison
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,TIMESTAMP'1001-01-01 10:20:30');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP'1001-01-01 10:20:30')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,TIMESTAMP'2001-01-00 00:00:00');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP'2001-01-00 00:00:00')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,TIMESTAMP'2040-01-01 10:20:30');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP'2040-01-01 10:20:30')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,'1001-01-01 10:20:30');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,'1001-01-01 10:20:30')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,'2001-01-00 00:00:00');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,'2001-01-00 00:00:00')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,'2040-01-01 10:20:30');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,'2040-01-01 10:20:30')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,10010101102030);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,10010101102030)
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010100000000);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,20010100000000)
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20400101102030);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,20400101102030)
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,10010101102030e0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,10010101102030e0)
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010100000000e0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,20010100000000e0)
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20400101102030e0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,20400101102030e0)
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,10010101102030.0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,10010101102030.0)
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010100000000.0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,20010100000000.0)
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20400101102030.0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,20400101102030.0)
+#
+# NULLIF: Good TIMESTAMP values switch to TIMESTAMP comparison
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,TIMESTAMP'0000-00-00 00:00:00');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP/*WITH LOCAL TIME ZONE*/'0000-00-00 00:00:00')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,TIMESTAMP'2001-01-01 10:20:30');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,'0000-00-00 00:00:00');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP/*WITH LOCAL TIME ZONE*/'0000-00-00 00:00:00')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,'2001-01-01 10:20:30');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP/*WITH LOCAL TIME ZONE*/'0000-00-00 00:00:00')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010101102030);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,0e0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP/*WITH LOCAL TIME ZONE*/'0000-00-00 00:00:00.000000')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010101102030e0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30.000000')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,0.0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP/*WITH LOCAL TIME ZONE*/'0000-00-00 00:00:00.0')
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010101102030.0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where nullif(`test`.`t1`.`a`,TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30.0')
+#
+# Subqueries with bad TIMESTAMP values
+# It's not clear from the output if the comparison is done as DATETIME or TIMESTAMP
+#
+CREATE TABLE t2 (a DATETIME);
+INSERT INTO t2 VALUES ('1001-01-01 10:20:30');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=(SELECT MAX(a) FROM t2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	1	100.00	
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = (/* select#2 */ select max('1001-01-01 10:20:30') from dual)
+DROP TABLE t2;
+CREATE TABLE t2 (a DATETIME);
+INSERT INTO t2 VALUES ('2001-00-00 00:00:00');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=(SELECT MAX(a) FROM t2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	1	100.00	
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = (/* select#2 */ select max('2001-00-00 00:00:00') from dual)
+DROP TABLE t2;
+CREATE TABLE t2 (a DATETIME);
+INSERT INTO t2 VALUES ('2040-01-01 10:20:30');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=(SELECT MAX(a) FROM t2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	1	100.00	
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = (/* select#2 */ select max('2040-01-01 10:20:30') from dual)
+DROP TABLE t2;
+#
+# Subqueries with good TIMESTAMP values
+# It's not clear from the output if the comparison is done as DATETIME or TIMESTAMP
+#
+CREATE TABLE t2 (a DATETIME);
+INSERT INTO t2 VALUES ('0000-00-00 00:00:00');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=(SELECT MAX(a) FROM t2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	1	100.00	
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = (/* select#2 */ select max('0000-00-00 00:00:00') from dual)
+DROP TABLE t2;
+CREATE TABLE t2 (a DATETIME);
+INSERT INTO t2 VALUES ('2001-01-01 10:20:30');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=(SELECT MAX(a) FROM t2);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+2	SUBQUERY	t2	system	NULL	NULL	NULL	NULL	1	100.00	
+Warnings:
+Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = (/* select#2 */ select max('2001-01-01 10:20:30') from dual)
+DROP TABLE t2;
+#
+# Trivial equality elimination
+# Covers Type_handler_timestamp_common::Item_const_eq()
+#
+EXPLAIN EXTENDED SELECT * FROM t1
+WHERE IF(a='2001-01-01 00:00:00',1,0)=IF(a='2001-01-01 00:00:00',1,0);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where if(`test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00',1,0) = if(`test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 00:00:00',1,0)
+EXECUTE IMMEDIATE 'EXPLAIN EXTENDED SELECT * FROM t1 WHERE (a<=>?)=(a<=>?)'
+    USING '2001-01-01 00:00:00', '2001-01-01 00:00:00';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where 1
+#
+# Equal field propagation: Good TIMESTAMP values switch to TIMESTAMP comparison
+#
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=TIMESTAMP'2001-01-01 10:20:30';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19 AND a='2001-01-01 10:20:30';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=20010101102030;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=20010101102030e0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30.000000'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=20010101102030.0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30.0'
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a=TIMESTAMP'2001-01-01 10:20:30';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30' and <cache>(octet_length(TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30')) = 19 + rand()
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a='2001-01-01 10:20:30';
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30' and <cache>(octet_length(TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30')) = 19 + rand()
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a=20010101102030;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30' and <cache>(octet_length(TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30')) = 19 + rand()
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a=20010101102030e0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30.000000' and <cache>(octet_length(TIMESTAMP'2001-01-01 10:20:30')) = 19 + rand()
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a=20010101102030.0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+Warnings:
+Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` = TIMESTAMP/*WITH LOCAL TIME ZONE*/'2001-01-01 10:20:30.0' and <cache>(octet_length(TIMESTAMP'2001-01-01 10:20:30')) = 19 + rand()
+DROP TABLE t1;
+SET time_zone=DEFAULT;
+#
+# End of 10.6 tests
+#
+#
 # MDEV-29225 make explicit_defaults_for_timestamps SESSION variable
 #
 set explicit_defaults_for_timestamp=OFF;
diff --git a/mysql-test/main/type_timestamp.test b/mysql-test/main/type_timestamp.test
index b3dfa19223d..34276caede4 100644
--- a/mysql-test/main/type_timestamp.test
+++ b/mysql-test/main/type_timestamp.test
@@ -907,6 +907,246 @@ SET time_zone=DEFAULT;
 --echo # End of 10.4 tests
 --echo #
 
+--echo #
+--echo # Start of 10.6 tests
+--echo #
+
+--echo #
+--echo # MDEV-32148 Inefficient WHERE timestamp_column=datetime_expr
+--echo #
+
+SET time_zone='+00:00';
+CREATE TABLE t1 (a TIMESTAMP);
+INSERT INTO t1 VALUES ('0000-00-00 00:00:00');
+INSERT INTO t1 VALUES ('2001-01-01 10:20:30'), ('2001-01-01 10:20:31');
+
+--echo #
+--echo # Comparison predicates: Bad TIMESTAMP values preserve DATETIME comparison
+--echo #
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1001-01-01 10:20:30';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2001-01-00 00:00:00';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2040-01-01 10:20:30';
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='1001-01-01 10:20:30';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-00 00:00:00';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2040-01-01 10:20:30';
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=10010101102030;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010100000000;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20400101102030;
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=10010101102030e0;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010100000000e0;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20400101102030e0;
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=10010101102030.0;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010100000000.0;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20400101102030.0;
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=DATE_ADD('2020-01-01 10:20:30', INTERVAL 30 YEAR);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE COALESCE(NULL, a)=DATE_ADD('2020-01-01 10:20:30', INTERVAL 30 YEAR);
+
+--echo #
+--echo # Comparison predicates: Good TIMESTAMP values switch to TIMESTAMP comparison
+--echo #
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'0000-00-00 00:00:00';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2001-01-01 10:20:30';
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='0000-00-00 00:00:00';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01 10:20:30';
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=0;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010101102030;
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=0e0;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010101102030e0;
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=0.0;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=20010101102030.0;
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=DATE_ADD('2001-01-01 10:20:00', INTERVAL 30 SECOND);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE COALESCE(NULL, a)=DATE_ADD('2001-01-01 10:20:00', INTERVAL 30 SECOND);
+
+--echo #
+--echo # Corner cases: DATETIME values before the supported optimization range
+--echo # FROM_UNIXTIME(0)..FROM_UNIXTIME(24*3600-1)
+--echo #
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 00:00:00';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 23:59:59';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 23:59:59.999999';
+
+# Truncation of the 7th flactional digit produces a NOTE only without --ps
+--disable_ps_protocol
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 23:59:59.9999999';
+--enable_ps_protocol
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=FROM_UNIXTIME(24*3600-1);
+
+--echo #
+--echo # Corner cases: DATETIME values inside the supported optimization range:
+--echo # FROM_UNIXTIME(24*3600) .. FROM_UNIXTIME(0x7FFFFFFF-24*3600)
+--echo #
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=FROM_UNIXTIME(24*3600);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-02 00:00:00';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2038-01-18 03:14:07';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=FROM_UNIXTIME(0x7FFFFFFF-24*3600);
+
+--echo #
+--echo # Corner cases: DATETIME values after the supported optimization range
+--echo # FROM_UNIXTIME(0x7FFFFFFF-24*3600+1) .. FROM_UNIXTIME(0x7FFFFFFF)
+--echo #
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=FROM_UNIXTIME(0x7FFFFFFF-24*3600+1);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2038-01-18 03:14:08';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2038-01-19 03:14:07';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=FROM_UNIXTIME(0x7FFFFFFF);
+
+--echo #
+--echo # Corner cases: rounding
+--echo #
+
+SET sql_mode=TIME_ROUND_FRACTIONAL;
+
+--echo #
+--echo # Not optimized (before the supported range)
+--echo #
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 23:59:59.999999';
+
+--echo #
+--echo # Optimized
+--echo #
+--disable_ps_protocol
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'1970-01-01 23:59:59.9999999';
+--enable_ps_protocol
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2038-01-18 03:14:07.999999';
+
+--echo #
+--echo # Not optimized (after the supported range)
+--echo #
+--disable_ps_protocol
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=TIMESTAMP'2038-01-18 03:14:07.9999999';
+--enable_ps_protocol
+
+SET sql_mode=DEFAULT;
+
+--echo #
+--echo # NULLIF: Bad TIMESTAMP values preserve DATETIME comparison
+--echo #
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,TIMESTAMP'1001-01-01 10:20:30');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,TIMESTAMP'2001-01-00 00:00:00');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,TIMESTAMP'2040-01-01 10:20:30');
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,'1001-01-01 10:20:30');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,'2001-01-00 00:00:00');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,'2040-01-01 10:20:30');
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,10010101102030);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010100000000);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20400101102030);
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,10010101102030e0);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010100000000e0);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20400101102030e0);
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,10010101102030.0);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010100000000.0);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20400101102030.0);
+
+--echo #
+--echo # NULLIF: Good TIMESTAMP values switch to TIMESTAMP comparison
+--echo #
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,TIMESTAMP'0000-00-00 00:00:00');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,TIMESTAMP'2001-01-01 10:20:30');
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,'0000-00-00 00:00:00');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,'2001-01-01 10:20:30');
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,0);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010101102030);
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,0e0);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010101102030e0);
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,0.0);
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE NULLIF(a,20010101102030.0);
+
+
+--echo #
+--echo # Subqueries with bad TIMESTAMP values
+--echo # It's not clear from the output if the comparison is done as DATETIME or TIMESTAMP
+--echo #
+
+CREATE TABLE t2 (a DATETIME);
+INSERT INTO t2 VALUES ('1001-01-01 10:20:30');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=(SELECT MAX(a) FROM t2);
+DROP TABLE t2;
+
+CREATE TABLE t2 (a DATETIME);
+INSERT INTO t2 VALUES ('2001-00-00 00:00:00');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=(SELECT MAX(a) FROM t2);
+DROP TABLE t2;
+
+CREATE TABLE t2 (a DATETIME);
+INSERT INTO t2 VALUES ('2040-01-01 10:20:30');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=(SELECT MAX(a) FROM t2);
+DROP TABLE t2;
+
+--echo #
+--echo # Subqueries with good TIMESTAMP values
+--echo # It's not clear from the output if the comparison is done as DATETIME or TIMESTAMP
+--echo #
+
+CREATE TABLE t2 (a DATETIME);
+INSERT INTO t2 VALUES ('0000-00-00 00:00:00');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=(SELECT MAX(a) FROM t2);
+DROP TABLE t2;
+
+CREATE TABLE t2 (a DATETIME);
+INSERT INTO t2 VALUES ('2001-01-01 10:20:30');
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE a=(SELECT MAX(a) FROM t2);
+DROP TABLE t2;
+
+--echo #
+--echo # Trivial equality elimination
+--echo # Covers Type_handler_timestamp_common::Item_const_eq()
+--echo #
+
+EXPLAIN EXTENDED SELECT * FROM t1
+WHERE IF(a='2001-01-01 00:00:00',1,0)=IF(a='2001-01-01 00:00:00',1,0);
+
+EXECUTE IMMEDIATE 'EXPLAIN EXTENDED SELECT * FROM t1 WHERE (a<=>?)=(a<=>?)'
+    USING '2001-01-01 00:00:00', '2001-01-01 00:00:00';
+
+
+--echo #
+--echo # Equal field propagation: Good TIMESTAMP values switch to TIMESTAMP comparison
+--echo #
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=TIMESTAMP'2001-01-01 10:20:30';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19 AND a='2001-01-01 10:20:30';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=20010101102030;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=20010101102030e0;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19 AND a=20010101102030.0;
+
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a=TIMESTAMP'2001-01-01 10:20:30';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a='2001-01-01 10:20:30';
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a=20010101102030;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a=20010101102030e0;
+EXPLAIN EXTENDED SELECT * FROM t1 WHERE LENGTH(a)=19+RAND() AND a=20010101102030.0;
+
+DROP TABLE t1;
+
+SET time_zone=DEFAULT;
+
+--echo #
+--echo # End of 10.6 tests
+--echo #
+
 --echo #
 --echo # MDEV-29225 make explicit_defaults_for_timestamps SESSION variable
 --echo #
diff --git a/mysql-test/suite/versioning/r/cte.result b/mysql-test/suite/versioning/r/cte.result
index 11d478ac456..4a9eba56006 100644
--- a/mysql-test/suite/versioning/r/cte.result
+++ b/mysql-test/suite/versioning/r/cte.result
@@ -40,7 +40,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	UNION	e	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	with ancestors as (/* select#2 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` where `test`.`e`.`name` = 'bill' and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1` union /* select#3 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` where `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1`)/* select#1 */ select `ancestors`.`emp_id` AS `emp_id`,`ancestors`.`name` AS `name`,`ancestors`.`mgr` AS `mgr`,`ancestors`.`salary` AS `salary` from `ancestors`
+Note	1003	with ancestors as (/* select#2 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` where `test`.`e`.`name` = 'bill' and `test`.`e`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`e`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' union /* select#3 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` where `test`.`e`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`e`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu')/* select#1 */ select `ancestors`.`emp_id` AS `emp_id`,`ancestors`.`name` AS `name`,`ancestors`.`mgr` AS `mgr`,`ancestors`.`salary` AS `salary` from `ancestors`
 select row_start into @ts_2 from emp where name="john";
 explain extended /* All report to 'Bill' */
 with recursive
@@ -64,7 +64,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	RECURSIVE UNION	<derived2>	ref	key0	key0	5	test.e.mgr	1	100.00	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	with recursive ancestors as (/* select#2 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` where `test`.`e`.`name` = 'bill' and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1` union /* select#3 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` join `ancestors` `a` where `a`.`emp_id` = `test`.`e`.`mgr` and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1`)/* select#1 */ select `ancestors`.`emp_id` AS `emp_id`,`ancestors`.`name` AS `name`,`ancestors`.`mgr` AS `mgr`,`ancestors`.`salary` AS `salary` from `ancestors`
+Note	1003	with recursive ancestors as (/* select#2 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` where `test`.`e`.`name` = 'bill' and `test`.`e`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`e`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' union /* select#3 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` join `ancestors` `a` where `a`.`emp_id` = `test`.`e`.`mgr` and `test`.`e`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`e`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu')/* select#1 */ select `ancestors`.`emp_id` AS `emp_id`,`ancestors`.`name` AS `name`,`ancestors`.`mgr` AS `mgr`,`ancestors`.`salary` AS `salary` from `ancestors`
 /* All report to 'Bill' */
 with recursive
 ancestors
@@ -105,7 +105,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	RECURSIVE UNION	<derived2>	ref	key0	key0	5	test.e.mgr	1	100.00	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	with recursive ancestors as (/* select#2 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` where `test`.`e`.`name` = 'bill' and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1` union /* select#3 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` join `ancestors` `a` where `a`.`emp_id` = `test`.`e`.`mgr` and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1`)/* select#1 */ select `ancestors`.`emp_id` AS `emp_id`,`ancestors`.`name` AS `name`,`ancestors`.`mgr` AS `mgr`,`ancestors`.`salary` AS `salary` from `ancestors`
+Note	1003	with recursive ancestors as (/* select#2 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` where `test`.`e`.`name` = 'bill' and `test`.`e`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`e`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' union /* select#3 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` join `ancestors` `a` where `a`.`emp_id` = `test`.`e`.`mgr` and `test`.`e`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`e`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu')/* select#1 */ select `ancestors`.`emp_id` AS `emp_id`,`ancestors`.`name` AS `name`,`ancestors`.`mgr` AS `mgr`,`ancestors`.`salary` AS `salary` from `ancestors`
 with recursive
 ancestors
 as
@@ -146,7 +146,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	RECURSIVE UNION	<derived2>	ref	key0	key0	5	test.e.mgr	1	100.00	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	with recursive ancestors as (/* select#2 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` where `test`.`e`.`name` = 'bill' and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1` union /* select#3 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` join `ancestors` `a` where `a`.`emp_id` = `test`.`e`.`mgr` and `test`.`e`.`row_end` > @`ts_1` and `test`.`e`.`row_start` <= @`ts_1`)/* select#1 */ select `test`.`emp`.`name` AS `name` from `test`.`emp` semi join (`ancestors`) where `ancestors`.`emp_id` = `test`.`emp`.`emp_id` and `test`.`emp`.`row_end` = TIMESTAMP'2038-01-19 03:14:07.999999'
+Note	1003	with recursive ancestors as (/* select#2 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` where `test`.`e`.`name` = 'bill' and `test`.`e`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`e`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' union /* select#3 */ select `test`.`e`.`emp_id` AS `emp_id`,`test`.`e`.`name` AS `name`,`test`.`e`.`mgr` AS `mgr`,`test`.`e`.`salary` AS `salary` from `test`.`emp` FOR SYSTEM_TIME AS OF TIMESTAMP @`ts_1` `e` join `ancestors` `a` where `a`.`emp_id` = `test`.`e`.`mgr` and `test`.`e`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`e`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu')/* select#1 */ select `test`.`emp`.`name` AS `name` from `test`.`emp` semi join (`ancestors`) where `ancestors`.`emp_id` = `test`.`emp`.`emp_id` and `test`.`emp`.`row_end` = TIMESTAMP'2038-01-19 03:14:07.999999'
 with recursive
 ancestors
 as
diff --git a/mysql-test/suite/versioning/r/derived.result b/mysql-test/suite/versioning/r/derived.result
index 700c92a8d5c..50cfb4020d0 100644
--- a/mysql-test/suite/versioning/r/derived.result
+++ b/mysql-test/suite/versioning/r/derived.result
@@ -211,12 +211,12 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using join buffer (flat, BNL join)
 Query A:
-Note	1003	select `test`.`t1`.`x` AS `x`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) join `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) where `test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t2`.`row_end` > <cache>(current_timestamp(6)) and `test`.`t2`.`row_start` <= <cache>(current_timestamp(6)) and `test`.`t1`.`row_end` > <cache>(current_timestamp(6)) and `test`.`t1`.`row_start` <= <cache>(current_timestamp(6))
+Note	1003	select `test`.`t1`.`x` AS `x`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) join `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) where `test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t2`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t2`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t1`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t1`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu'
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using join buffer (flat, BNL join)
 Query B:
-Note	1003	select `test`.`t1`.`x` AS `x`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) join `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) where `test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t2`.`row_end` > <cache>(current_timestamp(6)) and `test`.`t2`.`row_start` <= <cache>(current_timestamp(6)) and `test`.`t1`.`row_end` > <cache>(current_timestamp(6)) and `test`.`t1`.`row_start` <= <cache>(current_timestamp(6))
+Note	1003	select `test`.`t1`.`x` AS `x`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) join `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) where `test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t2`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t2`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t1`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t1`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu'
 Fine result: queries A and B are equal.
 ## LEFT JOIN: t1, t2 versioned
 select * from (
diff --git a/mysql-test/suite/versioning/r/select.result b/mysql-test/suite/versioning/r/select.result
index 36ea54bb08e..c4e8df1a743 100644
--- a/mysql-test/suite/versioning/r/select.result
+++ b/mysql-test/suite/versioning/r/select.result
@@ -155,21 +155,21 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
-Note	1003	select `test`.`t1`.`x` AS `IJ2_x1`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` join `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` where `test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t2`.`row_end` > @`t0` and `test`.`t2`.`row_start` <= @`t0` and `test`.`t1`.`row_end` > @`t0` and `test`.`t1`.`row_start` <= @`t0`
+Note	1003	select `test`.`t1`.`x` AS `IJ2_x1`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` join `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` where `test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t2`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t2`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t1`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t1`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu'
 explain extended select * from (select t1.x as LJ2_x1, t1.y as y1, t2.x as x2, t2.y as y2 from t1 left join t2 on t1.x = t2.x)
 for system_time as of timestamp @t0 as t;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
-Note	1003	select `test`.`t1`.`x` AS `LJ2_x1`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` left join `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` on(`test`.`t2`.`x` = `test`.`t1`.`x` and `test`.`t2`.`row_end` > @`t0` and `test`.`t2`.`row_start` <= @`t0`) where `test`.`t1`.`row_end` > @`t0` and `test`.`t1`.`row_start` <= @`t0`
+Note	1003	select `test`.`t1`.`x` AS `LJ2_x1`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` left join `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` on(`test`.`t2`.`x` = `test`.`t1`.`x` and `test`.`t2`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t2`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu') where `test`.`t1`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t1`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu'
 explain extended select * from (select t1.x as RJ2_x1, t1.y as y1, t2.x as x2, t2.y as y2 from t1 right join t2 on t1.x = t2.x)
 for system_time as of timestamp @t0 as t;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
-Note	1003	select `test`.`t1`.`x` AS `RJ2_x1`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` left join `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` on(`test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t1`.`row_end` > @`t0` and `test`.`t1`.`row_start` <= @`t0`) where `test`.`t2`.`row_end` > @`t0` and `test`.`t2`.`row_start` <= @`t0`
+Note	1003	select `test`.`t1`.`x` AS `RJ2_x1`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` left join `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP @`t0` on(`test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t1`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t1`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu') where `test`.`t2`.`row_end` > TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu' and `test`.`t2`.`row_start` <= TIMESTAMP/*WITH LOCAL TIME ZONE*/'YYYY-MM-DD hh:ss:mm:.uuuuuu'
 select * from (select t1.x as IJ2_x1, t1.y as y1, t2.x as x2, t2.y as y2 from t1 inner join t2 on t1.x = t2.x)
 for system_time as of timestamp @t0 as t;
 IJ2_x1	y1	x2	y2
diff --git a/mysql-test/suite/versioning/t/cte.test b/mysql-test/suite/versioning/t/cte.test
index 025e1b2319d..f57f7d14cef 100644
--- a/mysql-test/suite/versioning/t/cte.test
+++ b/mysql-test/suite/versioning/t/cte.test
@@ -5,6 +5,8 @@ if (`SELECT $PS_PROTOCOL != 0`)
 --source include/have_innodb.inc
 --source include/default_optimizer_switch.inc
 
+--let $replace_regex_tsltz6= /TIMESTAMP..WITH LOCAL TIME ZONE..'....-..-.. ..:..:..[.]......'/TIMESTAMP\/*WITH LOCAL TIME ZONE*\/'YYYY-MM-DD hh:ss:mm:.uuuuuu'/
+
 SET @saved_stats_persistent = @@GLOBAL.innodb_stats_persistent;
 SET GLOBAL innodb_stats_persistent = OFF;
 
@@ -42,6 +44,7 @@ select row_start into @ts_1 from emp where name="jane";
 
 update emp set mgr=30 where name ="john";
 
+--replace_regex $replace_regex_tsltz6
 explain extended
 with ancestors as (
   select e.emp_id, e.name, e.mgr, e.salary from emp as e where name = 'bill'
@@ -68,6 +71,7 @@ as
 )
 select * from ancestors;
 
+--replace_regex $replace_regex_tsltz6
 eval explain extended $q;
 eval $q;
 
@@ -86,6 +90,7 @@ as
 )
 select * from ancestors for system_time as of timestamp @ts_1;
 
+--replace_regex $replace_regex_tsltz6
 eval explain extended $q;
 eval $q;
 
@@ -104,6 +109,7 @@ as
 )
 select name from emp where emp_id in (select emp_id from ancestors for system_time as of timestamp @ts_1);
 
+--replace_regex $replace_regex_tsltz6
 eval explain extended $q;
 eval $q;
 
diff --git a/mysql-test/suite/versioning/t/derived.test b/mysql-test/suite/versioning/t/derived.test
index 9d96856f01f..f599ede97c1 100644
--- a/mysql-test/suite/versioning/t/derived.test
+++ b/mysql-test/suite/versioning/t/derived.test
@@ -1,5 +1,7 @@
 --source include/default_optimizer_switch.inc
 
+--let $replace_regex_tsltz6= /TIMESTAMP..WITH LOCAL TIME ZONE..'....-..-.. ..:..:..[.]......'/TIMESTAMP\/*WITH LOCAL TIME ZONE*\/'YYYY-MM-DD hh:ss:mm:.uuuuuu'/
+
 create table emp
 (
   emp_id int,
@@ -164,6 +166,7 @@ select * from (
   select t1.x, t1.y as y1, t2.x as x2, t2.y as y2
   from t1 join t2 on t1.x = t2.x) for system_time as of now() as t;
 
+--replace_regex $replace_regex_tsltz6
 let $a=`show warnings`;
 --echo Query A:
 echo $a;
@@ -174,6 +177,7 @@ select * from (
   from t1 for system_time as of now()
   join t2 for system_time as of now() on t1.x = t2.x) as t;
 
+--replace_regex $replace_regex_tsltz6
 let $b=`show warnings`;
 --echo Query B:
 echo $b;
diff --git a/mysql-test/suite/versioning/t/select.test b/mysql-test/suite/versioning/t/select.test
index 5603d1a3a12..b9a836f708e 100644
--- a/mysql-test/suite/versioning/t/select.test
+++ b/mysql-test/suite/versioning/t/select.test
@@ -6,6 +6,8 @@ if (`SELECT $PS_PROTOCOL != 0`)
 --source suite/versioning/common.inc
 --source include/default_optimizer_switch.inc
 
+--let $replace_regex_tsltz6= /TIMESTAMP..WITH LOCAL TIME ZONE..'....-..-.. ..:..:..[.]......'/TIMESTAMP\/*WITH LOCAL TIME ZONE*\/'YYYY-MM-DD hh:ss:mm:.uuuuuu'/
+
 SET @saved_stats_persistent = @@GLOBAL.innodb_stats_persistent;
 SET GLOBAL innodb_stats_persistent = OFF;
 
@@ -98,11 +100,14 @@ delete from t1;
 delete from t2;
 
 #384
+--replace_regex $replace_regex_tsltz6
 explain extended select * from (select t1.x as IJ2_x1, t1.y as y1, t2.x as x2, t2.y as y2 from t1 inner join t2 on t1.x = t2.x)
 for system_time as of timestamp @t0 as t;
+--replace_regex $replace_regex_tsltz6
 explain extended select * from (select t1.x as LJ2_x1, t1.y as y1, t2.x as x2, t2.y as y2 from t1 left join t2 on t1.x = t2.x)
 for system_time as of timestamp @t0 as t;
 #383
+--replace_regex $replace_regex_tsltz6
 explain extended select * from (select t1.x as RJ2_x1, t1.y as y1, t2.x as x2, t2.y as y2 from t1 right join t2 on t1.x = t2.x)
 for system_time as of timestamp @t0 as t;
 
diff --git a/sql/item.cc b/sql/item.cc
index a385cb67f30..f3e358f93e4 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -7332,6 +7332,17 @@ void Item_datetime_literal::print(String *str, enum_query_type query_type)
 }
 
 
+void Item_timestamp_literal::print(String *str, enum_query_type query_type)
+{
+  str->append(STRING_WITH_LEN("TIMESTAMP/*WITH LOCAL TIME ZONE*/'"));
+  char buf[MAX_DATE_STRING_REP_LENGTH];
+  Datetime dt= m_value.to_datetime(current_thd);
+  int length= my_datetime_to_str(dt.get_mysql_time(), buf, decimals);
+  str->append(buf, length);
+  str->append('\'');
+}
+
+
 Item *Item_datetime_literal::clone_item(THD *thd)
 {
   return new (thd->mem_root) Item_datetime_literal(thd, &cached_time, decimals);
diff --git a/sql/item.h b/sql/item.h
index 16ba4514421..3915d8a7ca0 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -5005,9 +5005,21 @@ class Item_timestamp_literal: public Item_literal
 public:
   Item_timestamp_literal(THD *thd)
    :Item_literal(thd)
-  { }
+  {
+    collation= DTCollation_numeric();
+  }
+  Item_timestamp_literal(THD *thd,
+                         const Timestamp_or_zero_datetime &value,
+                         decimal_digits_t dec)
+   :Item_literal(thd),
+    m_value(value)
+  {
+    collation= DTCollation_numeric();
+    decimals= dec;
+  }
   const Type_handler *type_handler() const override
   { return &type_handler_timestamp2; }
+  void print(String *str, enum_query_type query_type) override;
   int save_in_field(Field *field, bool) override
   {
     Timestamp_or_zero_datetime_native native(m_value, decimals);
@@ -5039,6 +5051,10 @@ public:
   {
     return m_value.to_native(to, decimals);
   }
+  const Timestamp_or_zero_datetime &value() const
+  {
+    return m_value;
+  }
   void set_value(const Timestamp_or_zero_datetime &value)
   {
     m_value= value;
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index b324a8f5e6a..d1891818cd6 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -392,6 +392,9 @@ static bool convert_const_to_int(THD *thd, Item_field *field_item,
   This directly contradicts the manual (number and a string should
   be compared as doubles), but seems to provide more
   "intuitive" behavior in some cases (but less intuitive in others).
+
+  This method should be moved to Type_handler::convert_item_for_comparison()
+  eventually.
 */
 void Item_func::convert_const_compared_to_int_field(THD *thd)
 {
@@ -412,6 +415,43 @@ void Item_func::convert_const_compared_to_int_field(THD *thd)
 }
 
 
+bool Item_func::aggregate_args2_for_comparison_with_conversion(
+                                            THD *thd,
+                                            Type_handler_hybrid_field_type *th)
+{
+  DBUG_ASSERT(arg_count >= 2);
+  for (bool done= false ; !done ; )
+  {
+    if (th->aggregate_for_comparison(func_name_cstring(), args, 2, false))
+      return true;
+    if (thd->lex->is_ps_or_view_context_analysis())
+      return false;
+    done= true;
+    for (uint subject= 0; subject < 2; subject++)
+    {
+      uint other_side= subject == 0 ? 1 : 0;
+      /* See comment in convert_const_to_int() */
+      if (!args[subject]->with_sum_func() &&
+          args[subject]->can_eval_in_optimize())
+      {
+        Item *item= th->type_handler()->convert_item_for_comparison(thd,
+                                                             args[subject],
+                                                             args[other_side]);
+        if (!item)
+          return true; // An error happened, e.g. EOM
+        if (item != args[subject])
+        {
+          thd->change_item_tree(&args[subject], item);
+          done= false; // Aggregate again, using the replacement item
+          break;
+        }
+      }
+    }
+  }
+  return false;
+}
+
+
 /*
   Iterate through arguments and compare them to the original arguments
   in "old_args". If some argument was replaced:
@@ -487,7 +527,7 @@ bool Item_bool_rowready_func2::fix_length_and_dec(THD *thd)
   Item_args old_args(args[0], args[1]);
   convert_const_compared_to_int_field(thd);
   Type_handler_hybrid_field_type tmp;
-  if (tmp.aggregate_for_comparison(func_name_cstring(), args, 2, false) ||
+  if (aggregate_args2_for_comparison_with_conversion(thd, &tmp) ||
       tmp.type_handler()->Item_bool_rowready_func2_fix_length_and_dec(thd,
                                                                       this))
   {
@@ -2804,7 +2844,10 @@ Item_func_nullif::fix_length_and_dec(THD *thd)
   set_maybe_null();
   m_arg0= args[0];
   convert_const_compared_to_int_field(thd);
-  if (cmp.set_cmp_func(thd, this, &args[0], &args[1], true/*set_null*/))
+  Type_handler_hybrid_field_type tmp;
+  if (aggregate_args2_for_comparison_with_conversion(thd, &tmp) ||
+      cmp.set_cmp_func(thd, this, tmp.type_handler(),
+                       &args[0], &args[1], true/*set_null*/))
     return true;
   /*
     A special code for EXECUTE..PREPARE.
diff --git a/sql/item_func.h b/sql/item_func.h
index e1d67a73134..5ec0e0f0608 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -83,6 +83,8 @@ protected:
     return print_sql_mode_qualified_name(to, query_type, func_name_cstring());
   }
 
+  bool aggregate_args2_for_comparison_with_conversion(THD *thd,
+                                           Type_handler_hybrid_field_type *th);
 public:
 
   // Print an error message for a builtin-schema qualified function call
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 9535bf1fee5..6d290995c99 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -1207,6 +1207,63 @@ void thd_gmt_sec_to_TIME(MYSQL_THD thd, MYSQL_TIME *ltime, my_time_t t)
 }
 
 
+/*
+  @brief
+  Convert a non-zero DATETIME to its safe timeval based representation,
+  which guarantees a safe roundtrip DATETIME->timeval->DATETIME,
+  e.g. to optimize:
+
+     WHERE timestamp_arg0 = datetime_arg1
+
+  in the way that we replace "datetime_arg1" to its TIMESTAMP equivalent
+  "timestamp_arg1" and switch from DATETIME comparison to TIMESTAMP comparison:
+
+     WHERE timestamp_arg0 = timestamp_arg1
+
+  This helps to avoid slow TIMESTAMP->DATETIME data type conversion
+  for timestamp_arg0 per row.
+
+  @detail
+  Round trip is possible if the input "YYYY-MM-DD hh:mm:ss" value
+  satisfies the following conditions:
+
+    1. TIME_to_gmt_sec() returns no errors or warnings,
+       which means the input value
+       a. has no zeros in YYYYMMDD
+       b. fits into the TIMESTAMP range
+       c. does not fall into the spring forward gap
+          (because values inside gaps get adjusted to the beginning of the gap)
+
+    2. The my_time_t value returned by TIME_to_gmt_sec() must not be
+       near a DST change or near a leap second, to avoid anomalies:
+       - "YYYY-MM-DD hh:mm:ss" has more than one matching my_time_t values
+       - "YYYY-MM-DD hh:mm:ss" has no matching my_time_t values
+         (e.g. fall into the spring forward gap)
+
+  @param dt   The DATETIME value to convert.
+              Must not be zero '0000-00-00 00:00:00.000000'.
+              (The zero value must be handled by the caller).
+
+  @return     The conversion result
+  @retval     If succeeded, non-NULL Timeval value.
+  @retval     Timeval_null value representing SQL NULL if the argument
+              does not have a safe replacement.
+*/
+Timeval_null
+THD::safe_timeval_replacement_for_nonzero_datetime(const Datetime &dt)
+{
+  used|= THD::TIME_ZONE_USED;
+  DBUG_ASSERT(non_zero_date(dt.get_mysql_time()));
+  uint error= 0;
+  const MYSQL_TIME *ltime= dt.get_mysql_time();
+  my_time_t sec= variables.time_zone->TIME_to_gmt_sec(ltime, &error);
+  if (error /* (1) */ ||
+      !variables.time_zone->is_monotone_continuous_around(sec) /* (2) */)
+    return Timeval_null();
+  return Timeval_null(sec, ltime->second_part);
+}
+
+
 #ifdef _WIN32
 extern "C" my_thread_id next_thread_id_noinline()
 {
diff --git a/sql/sql_class.h b/sql/sql_class.h
index bca0edd859e..2b959196db8 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -4283,6 +4283,8 @@ public:
     utime_after_query= current_utime();
   }
 
+  Timeval_null safe_timeval_replacement_for_nonzero_datetime(const Datetime &);
+
   /**
    Update server status after execution of a top level statement.
    Currently only checks if a query was slow, and assigns
diff --git a/sql/sql_type.cc b/sql/sql_type.cc
index c68809ec784..926d83c3fc9 100644
--- a/sql/sql_type.cc
+++ b/sql/sql_type.cc
@@ -7686,6 +7686,104 @@ Item *Type_handler_row::
   return NULL;
 }
 
+/***************************************************************************/
+
+/*
+  Check if in a predicate like:
+
+     WHERE timestamp_arg=datetime_arg
+
+  we can replace DATETIME comparison to TIMESTAMP comparison,
+  to avoid slow TIMESTAMP->DATETIME data type conversion per row.
+
+  TIMESTAMP and DATETIME are compared as DATETIME historically.
+  This may be inefficient, because involves a conversion of
+  the TIMESTAMP side to DATETIME per row.
+  The conversion happens in Timezone::gmt_sec_to_TIME().
+  E.g. in case of the SYSTEM timezone, it calls localtime_r(),
+  which is known to be slow.
+
+  It's generally not possible to compare TIMESTAMP and DATETIME
+  as TIMESTAMP without behavior change, because:
+  - DATETIME has a wider range.
+  - Two different TIMESTAMP values can have the same DATETIME value
+    near the "fall back" DST change, as well as for leap seconds.
+  - There are DATETIME gaps during the "spring forward" DST switch.
+
+  However, if the DATETIME side is a constant, then we can compare
+  it to TIMESTAMP as TIMESTAMP in many cases. The DATETIME argument can
+  be converted once to TIMESTAMP, so no data type conversion will
+  happen per row. This is faster for big tables.
+
+  The comparison predicates must satisfy the following conditions:
+    1. There must be a proper data type combination:
+       - other must be of the TIMESTAMP data type
+       - subject must be of the DATETIME data type,
+         or can convert to DATETIME.
+    2. subject must be a constant
+    3. subject must convert to TIMESTAMP safely
+       (without time zone anomalies near its value)
+*/
+
+Item *
+Type_handler_datetime_common::convert_item_for_comparison(
+                                                        THD *thd,
+                                                        Item *subject,
+                                                        const Item *counterpart)
+                                                        const
+{
+  if (!dynamic_cast<const Type_handler_timestamp_common*>(
+                                                 counterpart->type_handler()) ||
+      !subject->type_handler()->can_return_date())
+    return subject;
+
+  struct Count_handler : public Internal_error_handler
+  {
+    uint hit= 0;
+    bool handle_condition(THD *thd,
+                          uint sql_errno,
+                          const char *sqlstate,
+                          Sql_condition::enum_warning_level *level,
+                          const char *msg,
+                          Sql_condition **cond_hdl)
+    {
+      hit++;
+      return *level == Sql_condition::WARN_LEVEL_WARN;
+    }
+  } cnt_handler;
+
+  // Suppress and count warnings
+  thd->push_internal_handler(&cnt_handler);
+  Datetime dt(thd, subject, Timestamp::DatetimeOptions(thd));
+  thd->pop_internal_handler();
+
+  if (!dt.is_valid_datetime() || cnt_handler.hit)
+  {
+    /*
+      SQL NULL DATETIME, or a DATETIME with zeros in YYYYMMDD,
+      or warnings during DATETIME evaluation.
+    */
+    return subject;
+  }
+
+  // '0000-00-00 00:00:00' is a special valid MariaDB TIMESTAMP value
+  if (!non_zero_date(dt.get_mysql_time()))
+    return new (thd->mem_root) Item_timestamp_literal(thd,
+                                          Timestamp_or_zero_datetime::zero(),
+                                          subject->datetime_precision(thd));
+
+  const Timeval_null tv(thd->safe_timeval_replacement_for_nonzero_datetime(dt));
+  if (tv.is_null())
+    return subject; // Time zone anomalies found around "dt"
+
+  // Should be safe to convert
+  const Timestamp_or_zero_datetime ts(Timestamp(tv.to_timeval()));
+  return new (thd->mem_root) Item_timestamp_literal(thd,
+                                          ts,
+                                          subject->datetime_precision(thd));
+}
+
+
 /***************************************************************************/
 
 static const char* item_name(Item *a, String *str)
@@ -8686,6 +8784,43 @@ Type_handler_temporal_result::Item_const_eq(const Item_const *a,
           b->get_type_all_attributes_from_const()->decimals);
 }
 
+
+/*
+  @brief
+    Check if two costant timestamp values are identical.
+
+  @return
+    true <=> *a and *b are identical
+*/
+bool
+Type_handler_timestamp_common::Item_const_eq(const Item_const *a,
+                                             const Item_const *b,
+                                             bool binary_cmp) const
+{
+  /*
+    In a condition like:
+      WHERE IF(a='2001-01-01 00:00:00',1,0)=IF(a='2001-01-01 00:00:00',1,0);
+    Item_func_eq::fix_length_and_dec() calls get_timestamp_item_for_comparison()
+    which replaces string literals '2001-01-01 00:00:00' with
+    Item_timestamp_literal instances, which later during remove_eq_conds()
+    come to here.
+
+    Note, Item_param bound to TIMESTAMP is not detected here,
+    so trivial conditions of this kind do not get eliminated:
+      DECLARE ts TIMESTAMP DEFAULT (SELECT MAX(ts_col) FROM t1);
+      EXECUTE IMMEDIATE
+        'SELECT * FROM t1 WHERE COALESCE(ts_col,?)<=>COALESCE(ts_col,?)'
+         USING ts, ts;
+    It should be fixed by MDEV-14271.
+  */
+  const Item_timestamp_literal *ta, *tb;
+  if (!(ta= dynamic_cast<const Item_timestamp_literal*>(a)) ||
+      !(tb= dynamic_cast<const Item_timestamp_literal*>(b)))
+    return false;
+  return !ta->value().cmp(tb->value());
+}
+
+
 /***************************************************************************/
 
 const Type_handler *
diff --git a/sql/sql_type.h b/sql/sql_type.h
index 8215a3ee759..d41282ff9f9 100644
--- a/sql/sql_type.h
+++ b/sql/sql_type.h
@@ -2837,6 +2837,11 @@ public:
 class Timestamp_or_zero_datetime: protected Timestamp
 {
   bool m_is_zero_datetime;
+public:
+  static Timestamp_or_zero_datetime zero()
+  {
+    return Timestamp_or_zero_datetime(Timestamp(0, 0), true);
+  }
 public:
   Timestamp_or_zero_datetime()
    :Timestamp(0,0), m_is_zero_datetime(true)
@@ -2845,7 +2850,7 @@ public:
    :Timestamp(native.length() ? Timestamp(native) : Timestamp(0,0)),
     m_is_zero_datetime(native.length() == 0)
   { }
-  Timestamp_or_zero_datetime(const Timestamp &tm, bool is_zero_datetime)
+  Timestamp_or_zero_datetime(const Timestamp &tm, bool is_zero_datetime= false)
    :Timestamp(tm), m_is_zero_datetime(is_zero_datetime)
   { }
   Timestamp_or_zero_datetime(THD *thd, const MYSQL_TIME *ltime, uint *err_code);
@@ -2869,6 +2874,11 @@ public:
       return 1;
     return Timestamp::cmp(other);
   }
+  const Timestamp &to_timestamp() const
+  {
+    DBUG_ASSERT(!is_zero_datetime());
+    return *this;
+  }
   bool to_TIME(THD *thd, MYSQL_TIME *to, date_mode_t fuzzydate) const;
   /*
     Convert to native format:
@@ -4206,6 +4216,33 @@ public:
   virtual Item *make_const_item_for_comparison(THD *thd,
                                                Item *src,
                                                const Item *cmp) const= 0;
+  /**
+    When aggregating function arguments for comparison
+    (e.g. for  =, <, >, <=, >=, NULLIF), in some cases we rewrite
+    arguments. For example, if the predicate
+        timestamp_expr0 = datetime_const_expr1
+    decides to compare arguments as DATETIME,
+    we can try to rewrite datetime_const_expr1 to a TIMESTAMP constant
+    and perform the comparison as TIMESTAMP, which is faster because
+    does not have to perform TIMESTAMP->DATETIME data type conversion per row.
+
+    "this" is the type handler that is used to compare
+    "subject" and "counterpart" (DATETIME in the above example).
+    @param thd          the current thread
+    @param subject      the comparison side that we want try to rewrite
+    @param counterpart  the other comparison side
+    @retval             subject, if the subject does not need to be rewritten
+    @retval             NULL in case of error (e.g. EOM)
+    @retval             Otherwise, a pointer to a new Item which can
+                        be used as a replacement for the subject.
+  */
+  virtual Item *convert_item_for_comparison(THD *thd,
+                                            Item *subject,
+                                            const Item *counterpart) const
+  {
+    return subject;
+  }
+
   virtual Item_cache *Item_get_cache(THD *thd, const Item *item) const= 0;
   virtual Item *make_constructor_item(THD *thd, List<Item> *args) const
   {
@@ -6524,6 +6561,9 @@ public:
   }
   String *print_item_value(THD *thd, Item *item, String *str) const override;
   Item_cache *Item_get_cache(THD *thd, const Item *item) const override;
+  Item *convert_item_for_comparison(THD *thd,
+                                    Item *subject,
+                                    const Item *counterpart) const override;
   String *Item_func_min_max_val_str(Item_func_min_max *, String *) const override;
   double Item_func_min_max_val_real(Item_func_min_max *) const override;
   longlong Item_func_min_max_val_int(Item_func_min_max *) const override;
@@ -6695,6 +6735,8 @@ public:
   my_decimal *Item_func_min_max_val_decimal(Item_func_min_max *,
                                             my_decimal *) const override;
   bool set_comparator_func(THD *thd, Arg_comparator *cmp) const override;
+  bool Item_const_eq(const Item_const *a, const Item_const *b,
+                     bool binary_cmp) const override;
   bool Item_hybrid_func_fix_attributes(THD *thd,
                                        const LEX_CSTRING &name,
                                        Type_handler_hybrid_field_type *,
diff --git a/sql/structs.h b/sql/structs.h
index c8351efd8bf..029543ceb01 100644
--- a/sql/structs.h
+++ b/sql/structs.h
@@ -1035,4 +1035,29 @@ public:
 };
 
 
+/*
+  A value that's either a Timeval or SQL NULL
+*/
+
+class Timeval_null: protected Timeval
+{
+  bool m_is_null;
+public:
+  Timeval_null()
+   :Timeval(0, 0),
+    m_is_null(true)
+  { }
+  Timeval_null(const my_time_t sec, ulong usec)
+   :Timeval(sec, usec),
+    m_is_null(false)
+  { }
+  const Timeval & to_timeval() const
+  {
+    DBUG_ASSERT(!m_is_null);
+    return *this;
+  }
+  bool is_null() const { return m_is_null; }
+};
+
+
 #endif /* STRUCTS_INCLUDED */
diff --git a/sql/tztime.cc b/sql/tztime.cc
index 9a1f8c6fc52..0ccf3cc76eb 100644
--- a/sql/tztime.cc
+++ b/sql/tztime.cc
@@ -2426,6 +2426,59 @@ void Time_zone::adjust_leap_second(MYSQL_TIME *t)
     t->second= 59;
 }
 
+
+/*
+  @brief
+    Check if timestamp<->datetime conversion is guaranteed to be reversible
+    around the given time value.
+*/
+
+bool Time_zone::is_monotone_continuous_around(my_time_t sec) const
+{
+  const my_time_t width= 24 * 60 * 60;
+  /*
+    Let's check that the TIMESTAMP range [sec - width, sec + width]
+    converts back to a DATETIME range [dtmin, dtmax], and the difference
+    (dtmax-dtmin), calculated using DATETIME arithmetics,
+    is also equal to exactly 2*width.
+
+    This should almost guarantee that the TIMESTAMP range around sec
+    is monotone and continuous and thus has no DST changes or leap seconds.
+
+    It's still possible that there are two or more timezone offset changes
+    in the given range. But there are no such time zones according to
+    our knowledge.
+    Note, DST changes and leap seconds do not interfere on a short time_t range:
+    - Leap seconds happen in winter and summer
+    - DST changes happen in spring and fall
+
+    The largest time zone change that ever happened in a single place
+    was 24 hours:
+    - from SST (UTC-11) - the American Samoa Time Zone
+    - to WST (UTC+13) - the Independent State of Samoa Time Zone
+    The Independent State of Samoa used SST until it moved across
+    the International Date Line at the end of 29 December 2011, to WST.
+    It is now 24 hours ahead of American Samoa
+    (and 25 hours in Southern hemisphere summer).
+    Let's use 24 hours as width (48 hours range total).
+  */
+
+  if (sec < width || sec > TIMESTAMP_MAX_VALUE - width)
+    return false;
+
+  MYSQL_TIME dtmin, dtmax;
+  gmt_sec_to_TIME(&dtmin, sec - width);
+  gmt_sec_to_TIME(&dtmax, sec + width);
+
+  ulonglong seconds;
+  ulong useconds;
+  if (calc_time_diff(&dtmax, &dtmin, 1, &seconds, &useconds))
+    return false; // dtmax is smaller than dtmin, should not happen.
+  if (seconds != (ulonglong) width * 2)
+    return false; // Anomalies found (DST changes or leap seconds)
+  return true;
+}
+
 #endif /* !defined(TESTTIME) && !defined(TZINFO2SQL) */
 
 
diff --git a/sql/tztime.h b/sql/tztime.h
index 3dabbe8d118..3c394014946 100644
--- a/sql/tztime.h
+++ b/sql/tztime.h
@@ -80,6 +80,13 @@ public:
   */
   virtual ~Time_zone() = default;
 
+  /**
+    Check if the time zone does not have any anomalies around "sec", such as:
+    - DST changes (spring forward, fall back)
+    - leap seconds (the 60-th second)
+  */
+  bool is_monotone_continuous_around(my_time_t sec) const;
+
 protected:
   static inline void adjust_leap_second(MYSQL_TIME *t);
 };
diff --git a/storage/spider/mysql-test/spider/r/timestamp.result b/storage/spider/mysql-test/spider/r/timestamp.result
index 4618d9207bf..a717860ab6c 100644
--- a/storage/spider/mysql-test/spider/r/timestamp.result
+++ b/storage/spider/mysql-test/spider/r/timestamp.result
@@ -257,7 +257,7 @@ select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timest
 select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where (_latin1'2018-10-28 01:30:00' > t0.`col_ts`)
 select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where (t0.`col_ts` between _latin1'2018-10-28 00:30:00'  and  _latin1'2018-10-28 01:30:00')
 select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where ((t0.`col_ts` >= _latin1'2018-10-28 00:30:00') and (t0.`col_ts` <= _latin1'2018-10-28 01:30:00'))
-select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where (t0.`col_ts` > '2018-03-25 01:00:00')
+select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where (t0.`col_ts` > _latin1'2018-03-25 01:00:00')
 select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where (t0.`col_ts` > '1970-01-01 00:00:01')
 SELECT argument FROM mysql.general_log WHERE command_type != 'Execute' AND argument LIKE '%select %'
 SELECT col_a, col_dt, col_ts, unix_timestamp(col_ts) FROM tbl_a ORDER BY col_a;
@@ -344,7 +344,7 @@ select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timest
 select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where (_latin1'2018-10-28 01:30:00' > t0.`col_ts`)
 select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where (t0.`col_ts` between _latin1'2018-10-28 00:30:00'  and  _latin1'2018-10-28 01:30:00')
 select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where ((t0.`col_ts` >= _latin1'2018-10-28 00:30:00') and (t0.`col_ts` <= _latin1'2018-10-28 01:30:00'))
-select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where (t0.`col_ts` > '2018-03-25 01:00:00')
+select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where (t0.`col_ts` > _latin1'2018-03-25 01:00:00')
 select t0.`col_a` `col_a`,t0.`col_dt` `col_dt`,t0.`col_ts` `col_ts`,(unix_timestamp(t0.`col_ts`)) `unix_timestamp(col_ts)` from `ts_test_remote`.`tbl_a` t0 where (t0.`col_ts` > '1970-01-01 00:00:01')
 SELECT argument FROM mysql.general_log WHERE command_type != 'Execute' AND argument LIKE '%select %'
 SELECT col_a, col_dt, col_ts, unix_timestamp(col_ts) FROM tbl_a ORDER BY col_a;