MDEV-26938 Support descending indexes internally in InnoDB

This is loosely based on the InnoDB changes in
mysql/mysql-server@97fd8b1b6993340b361fa7f85da86a308f0b5e0c
that I had developed in 2015 or 2016.

For each B-tree key field, we will allow a flag ASC/DESC to be associated.
When PRIMARY KEY fields are internally appended to secondary indexes,
the ASC/DESC attribute will be inherited, so that covering index scans
will work as expected.

Note: Until the subsequent commit, the DESC attribute will be ignored
(no HA_REVERSE_SORT flag will be written to .frm files).

dict_field_t::descending: A new flag to denote descending order.

cmp_data(), cmp_dfield_dfield(): Add a new parameter descending.

cmp_dtuple_rec(), cmp_dtuple_rec_with_match(): Add a parameter "index".

dtuple_coll_eq(): Replaces dtuple_coll_cmp().

cmp_dfield_dfield_eq_prefix(): Replaces cmp_dfield_dfield_like_prefix().

dict_index_t::is_btree(): Check whether the index is a regular
B-tree index (not SPATIAL, FULLTEXT, or the ibuf.index,
or a corrupted index.

btr_cur_search_to_nth_level_func(): Only attempt to use
the adaptive hash index if index->is_btree().
This function may also be invoked on ibuf.index, and
cmp_dtuple_rec_with_match_bytes() will no longer work on ibuf.index
because it assumes that the index and record fields exactly match.
The ibuf.index is a special variadic index tree.

Thanks to Thirunarayanan Balathandayuthapani for fixing some bugs:
MDEV-27439, MDEV-27374/MDEV-27445.

43 files changed, 797 insertions, 644 deletions

diff --git a/mysql-test/suite/innodb/r/autoinc_persist,desc.rdiff b/mysql-test/suite/innodb/r/autoinc_persist,desc.rdiff
new file mode 100644
index 00000000000..eeef34e071d
--- /dev/null
+++ b/mysql-test/suite/innodb/r/autoinc_persist,desc.rdiff
@@ -0,0 +1,162 @@
+@@ -13,7 +13,7 @@
+ #
+ # Pre-create several tables
+ SET SQL_MODE='STRICT_ALL_TABLES';
+-CREATE TABLE t1(a TINYINT AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t1(a TINYINT AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t1 VALUES(0), (0), (0), (0), (-1), (-10), (0),
+ (20), (30), (31);
+ SELECT * FROM t1;
+@@ -28,7 +28,7 @@
+ 20
+ 30
+ 31
+-CREATE TABLE t2(a TINYINT UNSIGNED AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t2(a TINYINT UNSIGNED AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t2 VALUES(-5);
+ ERROR 22003: Out of range value for column 'a' at row 1
+ INSERT INTO t2 VALUES(0), (0), (0), (0), (8), (10), (0),
+@@ -45,7 +45,7 @@
+ 20
+ 30
+ 31
+-CREATE TABLE t3(a SMALLINT AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t3(a SMALLINT AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t3 VALUES(0), (0), (0), (0), (-1), (-10), (0),
+ (20), (30), (31), (1024), (4096);
+ SELECT * FROM t3;
+@@ -62,7 +62,7 @@
+ 31
+ 1024
+ 4096
+-CREATE TABLE t4(a SMALLINT UNSIGNED AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t4(a SMALLINT UNSIGNED AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t4 VALUES(-5);
+ ERROR 22003: Out of range value for column 'a' at row 1
+ INSERT INTO t4 VALUES(0), (0), (0), (0), (8), (10), (0),
+@@ -81,7 +81,7 @@
+ 31
+ 1024
+ 4096
+-CREATE TABLE t5(a MEDIUMINT AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t5(a MEDIUMINT AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t5 VALUES(0), (0), (0), (0), (-1), (-10), (0),
+ (20), (30), (31), (1000000), (1000005);
+ SELECT * FROM t5;
+@@ -98,7 +98,7 @@
+ 31
+ 1000000
+ 1000005
+-CREATE TABLE t6(a MEDIUMINT UNSIGNED AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t6(a MEDIUMINT UNSIGNED AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t6 VALUES(-5);
+ ERROR 22003: Out of range value for column 'a' at row 1
+ INSERT INTO t6 VALUES(0), (0), (0), (0), (8), (10), (0),
+@@ -117,7 +117,7 @@
+ 31
+ 1000000
+ 1000005
+-CREATE TABLE t7(a INT AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t7(a INT AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t7 VALUES(0), (0), (0), (0), (-1), (-10), (0),
+ (20), (30), (31), (100000000), (100000008);
+ SELECT * FROM t7;
+@@ -134,7 +134,7 @@
+ 31
+ 100000000
+ 100000008
+-CREATE TABLE t8(a INT UNSIGNED AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t8(a INT UNSIGNED AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t8 VALUES(-5);
+ ERROR 22003: Out of range value for column 'a' at row 1
+ INSERT INTO t8 VALUES(0), (0), (0), (0), (8), (10), (0),
+@@ -153,7 +153,7 @@
+ 31
+ 100000000
+ 100000008
+-CREATE TABLE t9(a BIGINT AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t9(a BIGINT AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t9 VALUES(0), (0), (0), (0), (-1), (-10), (0),
+ (20), (30), (31), (100000000000), (100000000006);
+ SELECT * FROM t9;
+@@ -170,7 +170,7 @@
+ 31
+ 100000000000
+ 100000000006
+-CREATE TABLE t10(a BIGINT UNSIGNED AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t10(a BIGINT UNSIGNED AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t10 VALUES(-5);
+ ERROR 22003: Out of range value for column 'a' at row 1
+ INSERT INTO t10 VALUES(0), (0), (0), (0), (8), (10), (0),
+@@ -189,7 +189,7 @@
+ 31
+ 100000000000
+ 100000000006
+-CREATE TABLE t11(a FLOAT AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t11(a FLOAT AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t11 VALUES(0), (0), (0), (0), (-1), (-10), (0),
+ (20), (30), (31);
+ SELECT * FROM t11;
+@@ -204,7 +204,7 @@
+ 20
+ 30
+ 31
+-CREATE TABLE t12(a DOUBLE AUTO_INCREMENT KEY) ENGINE = InnoDB;
++CREATE TABLE t12(a DOUBLE AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB;
+ INSERT INTO t12 VALUES(0), (0), (0), (0), (-1), (-10), (0),
+ (20), (30), (31);
+ SELECT * FROM t12;
+@@ -242,7 +242,7 @@
+ SELECT MAX(a) AS `Expect 100000000000` FROM t9;
+ Expect 100000000000
+ 100000000000
+-CREATE TABLE t13(a INT AUTO_INCREMENT KEY) ENGINE = InnoDB,
++CREATE TABLE t13(a INT AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE = InnoDB,
+ AUTO_INCREMENT = 1234;
+ # restart
+ SHOW CREATE TABLE t13;
+@@ -842,7 +842,7 @@
+ 126
+ DROP TABLE t_copy, it_copy;
+ # Scenario 9: Test the sql_mode = NO_AUTO_VALUE_ON_ZERO
+-CREATE TABLE t30 (a INT NOT NULL AUTO_INCREMENT PRIMARY KEY, b INT, key(b)) ENGINE = InnoDB;
++CREATE TABLE t30 (a INT NOT NULL AUTO_INCREMENT, PRIMARY KEY(a DESC), b INT, key(b)) ENGINE = InnoDB;
+ set SQL_MODE = NO_AUTO_VALUE_ON_ZERO;
+ INSERT INTO t30 VALUES(NULL, 1), (200, 2), (0, 3);
+ INSERT INTO t30(b) VALUES(4), (5), (6), (7);
+@@ -869,7 +869,7 @@
+ set global innodb_flush_log_at_trx_commit=1;
+ CREATE TABLE t31 (a INT) ENGINE = InnoDB;
+ INSERT INTO t31 VALUES(1), (2);
+-ALTER TABLE t31 ADD b INT AUTO_INCREMENT PRIMARY KEY;
++ALTER TABLE t31 ADD b INT AUTO_INCREMENT, ADD PRIMARY KEY(b DESC);
+ INSERT INTO t31 VALUES(3, 0), (4, NULL), (5, NULL);
+ INSERT INTO t31 VALUES(6, 0);
+ ERROR 23000: Duplicate entry '0' for key 'PRIMARY'
+@@ -882,7 +882,7 @@
+ 5	4
+ SET SQL_MODE = 0;
+ # Scenario 10: Rollback would not rollback the counter
+-CREATE TABLE t32 (a BIGINT AUTO_INCREMENT PRIMARY KEY) ENGINE=InnoDB;
++CREATE TABLE t32 (a BIGINT AUTO_INCREMENT, PRIMARY KEY(a DESC)) ENGINE=InnoDB;
+ INSERT INTO t32 VALUES(0), (0);
+ # Ensure that all changes before the server is killed are persisted.
+ set global innodb_flush_log_at_trx_commit=1;
+@@ -897,7 +897,7 @@
+ # increasing the counter
+ CREATE TABLE t33 (
+ a BIGINT NOT NULL PRIMARY KEY,
+-b BIGINT NOT NULL AUTO_INCREMENT, KEY(b)) ENGINE = InnoDB;
++b BIGINT NOT NULL AUTO_INCREMENT, INDEX(b DESC)) ENGINE = InnoDB;
+ INSERT INTO t33 VALUES(1, NULL);
+ INSERT INTO t33 VALUES(2, NULL);
+ INSERT INTO t33 VALUES(2, NULL);
+@@ -965,7 +965,7 @@
+ DROP TABLE t33;
+ CREATE TABLE t33 (
+ a BIGINT NOT NULL PRIMARY KEY,
+-b BIGINT NOT NULL AUTO_INCREMENT, KEY(b)) ENGINE = InnoDB;
++b BIGINT NOT NULL AUTO_INCREMENT, INDEX(b DESC)) ENGINE = InnoDB;
+ ALTER TABLE t33 DISCARD TABLESPACE;
+ restore: t33 .ibd and .cfg files
+ ALTER TABLE t33 IMPORT TABLESPACE;
diff --git a/mysql-test/suite/innodb/r/autoinc_persist.result b/mysql-test/suite/innodb/r/autoinc_persist.result
index ee796160406..91d6d908a82 100644
--- a/mysql-test/suite/innodb/r/autoinc_persist.result
+++ b/mysql-test/suite/innodb/r/autoinc_persist.result
@@ -242,7 +242,7 @@ DELETE FROM t9 WHERE a > 100000000000;
 SELECT MAX(a) AS `Expect 100000000000` FROM t9;
 Expect 100000000000
 100000000000
-CREATE TABLE t13(a INT AUTO_INCREMENT PRIMARY KEY) ENGINE = InnoDB,
+CREATE TABLE t13(a INT AUTO_INCREMENT KEY) ENGINE = InnoDB,
 AUTO_INCREMENT = 1234;
 # restart
 SHOW CREATE TABLE t13;
@@ -882,8 +882,7 @@ a	b
 5	4
 SET SQL_MODE = 0;
 # Scenario 10: Rollback would not rollback the counter
-CREATE TABLE t32 (
-a BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT) ENGINE=InnoDB;
+CREATE TABLE t32 (a BIGINT AUTO_INCREMENT PRIMARY KEY) ENGINE=InnoDB;
 INSERT INTO t32 VALUES(0), (0);
 # Ensure that all changes before the server is killed are persisted.
 set global innodb_flush_log_at_trx_commit=1;
@@ -898,8 +897,7 @@ ROLLBACK;
 # increasing the counter
 CREATE TABLE t33 (
 a BIGINT NOT NULL PRIMARY KEY,
-b BIGINT NOT NULL AUTO_INCREMENT,
-KEY(b)) ENGINE = InnoDB;
+b BIGINT NOT NULL AUTO_INCREMENT, KEY(b)) ENGINE = InnoDB;
 INSERT INTO t33 VALUES(1, NULL);
 INSERT INTO t33 VALUES(2, NULL);
 INSERT INTO t33 VALUES(2, NULL);
@@ -967,8 +965,7 @@ UNLOCK TABLES;
 DROP TABLE t33;
 CREATE TABLE t33 (
 a BIGINT NOT NULL PRIMARY KEY,
-b BIGINT NOT NULL AUTO_INCREMENT,
-KEY(b)) ENGINE = InnoDB;
+b BIGINT NOT NULL AUTO_INCREMENT, KEY(b)) ENGINE = InnoDB;
 ALTER TABLE t33 DISCARD TABLESPACE;
 restore: t33 .ibd and .cfg files
 ALTER TABLE t33 IMPORT TABLESPACE;
diff --git a/mysql-test/suite/innodb/r/innodb-index.result b/mysql-test/suite/innodb/r/innodb-index.result
index 1bcb4e620bb..b0c0c26afd4 100644
--- a/mysql-test/suite/innodb/r/innodb-index.result
+++ b/mysql-test/suite/innodb/r/innodb-index.result
@@ -1947,3 +1947,51 @@ Warnings:
 Warning	1082	InnoDB: Table test/t contains 0 indexes inside InnoDB, which is different from the number of indexes 1 defined in the MariaDB 
 Warning	1082	InnoDB: Table test/t contains 0 indexes inside InnoDB, which is different from the number of indexes 1 defined in the MariaDB 
 DROP TABLE t;
+#
+#  MDEV-27374  InnoDB table becomes corrupt after renaming DESC-indexed column
+#
+CREATE TABLE t1 (a VARCHAR(8), PRIMARY KEY(a DESC)) ENGINE=InnoDB;
+ALTER TABLE t1 RENAME COLUMN a TO b, ALGORITHM=INPLACE;
+SELECT TABLE_ID INTO @table_id FROM INFORMATION_SCHEMA.INNODB_SYS_TABLES WHERE NAME="test/t1";
+SELECT INDEX_ID INTO @index_id FROM INFORMATION_SCHEMA.INNODB_SYS_INDEXES WHERE TABLE_ID = @table_id;
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_SYS_FIELDS WHERE INDEX_ID=@index_id;
+NAME
+b
+DROP TABLE t1;
+#
+#  MDEV-27432 ASC/DESC primary and unique keys cause index
+#	inconsistency between InnoDB and server
+#
+CREATE TABLE t1 (id INT NOT NULL, UNIQUE(id DESC)) ENGINE=InnoDB;
+ALTER TABLE t1 ADD PRIMARY KEY (id), ALGORITHM=INPLACE;
+SHOW CREATE TABLE t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `id` int(11) NOT NULL,
+  PRIMARY KEY (`id`),
+  UNIQUE KEY `id` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+DROP TABLE t1;
+#
+#  MDEV-27445 Index inconsistency and assertion failure after
+#	renaming virtual column with DESC key
+#
+CREATE TABLE t1(a INT, b INT AS (a), KEY(a, b DESC)) ENGINE=InnoDB;
+ALTER TABLE t1 RENAME COLUMN IF EXISTS b TO v;
+ALTER TABLE t1 FORCE;
+DROP TABLE t1;
+#
+#  MDEV-27592 DESC primary index fails to set wide format
+#	while renaming the column
+#
+CREATE TABLE t1 (id INT PRIMARY KEY, a CHAR(8), b INT, KEY(a DESC,b)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (1,'foo',10);
+ALTER TABLE t1 RENAME COLUMN b TO c, ALGORITHM=INPLACE;
+SELECT TABLE_ID INTO @table_id FROM INFORMATION_SCHEMA.INNODB_SYS_TABLES WHERE NAME="test/t1";
+SELECT INDEX_ID INTO @index_id FROM INFORMATION_SCHEMA.INNODB_SYS_INDEXES WHERE TABLE_ID = @table_id ORDER BY INDEX_ID DESC LIMIT 1;
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_SYS_FIELDS WHERE INDEX_ID=@index_id;
+NAME
+a
+c
+DROP TABLE t1;
+# End of 10.8 tests
diff --git a/mysql-test/suite/innodb/t/autoinc_persist.combinations b/mysql-test/suite/innodb/t/autoinc_persist.combinations
new file mode 100644
index 00000000000..4ae2948e523
--- /dev/null
+++ b/mysql-test/suite/innodb/t/autoinc_persist.combinations
@@ -0,0 +1,2 @@
+[asc]
+[desc]
diff --git a/mysql-test/suite/innodb/t/autoinc_persist.test b/mysql-test/suite/innodb/t/autoinc_persist.test
index 6e094b40e02..c6135b5580c 100644
--- a/mysql-test/suite/innodb/t/autoinc_persist.test
+++ b/mysql-test/suite/innodb/t/autoinc_persist.test
@@ -2,6 +2,19 @@
 # Restarting is not supported when testing the embedded server.
 --source include/not_embedded.inc
 
+if ($MTR_COMBINATION_DESC) {
+  let $AUTO_INCREMENT_KEY_a= AUTO_INCREMENT, PRIMARY KEY(a DESC);
+  let $AUTO_INCREMENT_KEY_b= AUTO_INCREMENT, INDEX(b DESC);
+  let $AUTO_INCREMENT_PRIMARY_KEY_a= AUTO_INCREMENT, PRIMARY KEY(a DESC);
+  let $AUTO_INCREMENT_PRIMARY_KEY_b= AUTO_INCREMENT, ADD PRIMARY KEY(b DESC);
+}
+if (!$MTR_COMBINATION_DESC) {
+  let $AUTO_INCREMENT_KEY_a= AUTO_INCREMENT KEY;
+  let $AUTO_INCREMENT_KEY_b= AUTO_INCREMENT, KEY(b);
+  let $AUTO_INCREMENT_PRIMARY_KEY_a= AUTO_INCREMENT PRIMARY KEY;
+  let $AUTO_INCREMENT_PRIMARY_KEY_b= AUTO_INCREMENT PRIMARY KEY;
+}
+
 --echo #
 --echo # MDEV-6076 Persistent AUTO_INCREMENT for InnoDB
 --echo #
@@ -20,72 +33,72 @@
 
 SET SQL_MODE='STRICT_ALL_TABLES';
 
-CREATE TABLE t1(a TINYINT AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t1(a TINYINT $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 INSERT INTO t1 VALUES(0), (0), (0), (0), (-1), (-10), (0),
 (20), (30), (31);
 SELECT * FROM t1;
 
-CREATE TABLE t2(a TINYINT UNSIGNED AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t2(a TINYINT UNSIGNED $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 --error ER_WARN_DATA_OUT_OF_RANGE
 INSERT INTO t2 VALUES(-5);
 INSERT INTO t2 VALUES(0), (0), (0), (0), (8), (10), (0),
 (20), (30), (31);
 SELECT * FROM t2;
 
-CREATE TABLE t3(a SMALLINT AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t3(a SMALLINT $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 INSERT INTO t3 VALUES(0), (0), (0), (0), (-1), (-10), (0),
 (20), (30), (31), (1024), (4096);
 SELECT * FROM t3;
 
-CREATE TABLE t4(a SMALLINT UNSIGNED AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t4(a SMALLINT UNSIGNED $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 --error ER_WARN_DATA_OUT_OF_RANGE
 INSERT INTO t4 VALUES(-5);
 INSERT INTO t4 VALUES(0), (0), (0), (0), (8), (10), (0),
 (20), (30), (31), (1024), (4096);
 SELECT * FROM t4;
 
-CREATE TABLE t5(a MEDIUMINT AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t5(a MEDIUMINT $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 INSERT INTO t5 VALUES(0), (0), (0), (0), (-1), (-10), (0),
 (20), (30), (31), (1000000), (1000005);
 SELECT * FROM t5;
 
-CREATE TABLE t6(a MEDIUMINT UNSIGNED AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t6(a MEDIUMINT UNSIGNED $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 --error ER_WARN_DATA_OUT_OF_RANGE
 INSERT INTO t6 VALUES(-5);
 INSERT INTO t6 VALUES(0), (0), (0), (0), (8), (10), (0),
 (20), (30), (31), (1000000), (1000005);
 SELECT * FROM t6;
 
-CREATE TABLE t7(a INT AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t7(a INT $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 INSERT INTO t7 VALUES(0), (0), (0), (0), (-1), (-10), (0),
 (20), (30), (31), (100000000), (100000008);
 SELECT * FROM t7;
 
-CREATE TABLE t8(a INT UNSIGNED AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t8(a INT UNSIGNED $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 --error ER_WARN_DATA_OUT_OF_RANGE
 INSERT INTO t8 VALUES(-5);
 INSERT INTO t8 VALUES(0), (0), (0), (0), (8), (10), (0),
 (20), (30), (31), (100000000), (100000008);
 SELECT * FROM t8;
 
-CREATE TABLE t9(a BIGINT AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t9(a BIGINT $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 INSERT INTO t9 VALUES(0), (0), (0), (0), (-1), (-10), (0),
 (20), (30), (31), (100000000000), (100000000006);
 SELECT * FROM t9;
 
-CREATE TABLE t10(a BIGINT UNSIGNED AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t10(a BIGINT UNSIGNED $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 --error ER_WARN_DATA_OUT_OF_RANGE
 INSERT INTO t10 VALUES(-5);
 INSERT INTO t10 VALUES(0), (0), (0), (0), (8), (10), (0),
 (20), (30), (31), (100000000000), (100000000006);
 SELECT * FROM t10;
 
-CREATE TABLE t11(a FLOAT AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t11(a FLOAT $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 INSERT INTO t11 VALUES(0), (0), (0), (0), (-1), (-10), (0),
 (20), (30), (31);
 SELECT * FROM t11;
 
-CREATE TABLE t12(a DOUBLE AUTO_INCREMENT KEY) ENGINE = InnoDB;
+eval CREATE TABLE t12(a DOUBLE $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB;
 INSERT INTO t12 VALUES(0), (0), (0), (0), (-1), (-10), (0),
 (20), (30), (31);
 SELECT * FROM t12;
@@ -105,7 +118,7 @@ SELECT MAX(a) AS `Expect 100000000` FROM t7;
 DELETE FROM t9 WHERE a > 100000000000;
 SELECT MAX(a) AS `Expect 100000000000` FROM t9;
 
-CREATE TABLE t13(a INT AUTO_INCREMENT PRIMARY KEY) ENGINE = InnoDB,
+eval CREATE TABLE t13(a INT $AUTO_INCREMENT_KEY_a) ENGINE = InnoDB,
 AUTO_INCREMENT = 1234;
 
 --source include/restart_mysqld.inc
@@ -439,7 +452,7 @@ INSERT INTO t3 VALUES(0), (0), (200), (210);
 
 --echo # Scenario 9: Test the sql_mode = NO_AUTO_VALUE_ON_ZERO
 
-CREATE TABLE t30 (a INT NOT NULL AUTO_INCREMENT PRIMARY KEY, b INT, key(b)) ENGINE = InnoDB;
+eval CREATE TABLE t30 (a INT NOT NULL $AUTO_INCREMENT_PRIMARY_KEY_a, b INT, key(b)) ENGINE = InnoDB;
 
 set SQL_MODE = NO_AUTO_VALUE_ON_ZERO;
 
@@ -454,7 +467,7 @@ set global innodb_flush_log_at_trx_commit=1;
 
 CREATE TABLE t31 (a INT) ENGINE = InnoDB;
 INSERT INTO t31 VALUES(1), (2);
-ALTER TABLE t31 ADD b INT AUTO_INCREMENT PRIMARY KEY;
+eval ALTER TABLE t31 ADD b INT $AUTO_INCREMENT_PRIMARY_KEY_b;
 INSERT INTO t31 VALUES(3, 0), (4, NULL), (5, NULL);
 --error ER_DUP_ENTRY
 INSERT INTO t31 VALUES(6, 0);
@@ -463,8 +476,7 @@ SELECT * FROM t31;
 SET SQL_MODE = 0;
 
 --echo # Scenario 10: Rollback would not rollback the counter
-CREATE TABLE t32 (
-a BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT) ENGINE=InnoDB;
+eval CREATE TABLE t32 (a BIGINT $AUTO_INCREMENT_PRIMARY_KEY_a) ENGINE=InnoDB;
 
 INSERT INTO t32 VALUES(0), (0);
 
@@ -480,10 +492,9 @@ ROLLBACK;
 --echo # Scenario 11: Test duplicate primary key/secondary key will not stop
 --echo # increasing the counter
 
-CREATE TABLE t33 (
+eval CREATE TABLE t33 (
 a BIGINT NOT NULL PRIMARY KEY,
-b BIGINT NOT NULL AUTO_INCREMENT,
-KEY(b)) ENGINE = InnoDB;
+b BIGINT NOT NULL $AUTO_INCREMENT_KEY_b) ENGINE = InnoDB;
 
 INSERT INTO t33 VALUES(1, NULL);
 INSERT INTO t33 VALUES(2, NULL);
@@ -539,10 +550,9 @@ ib_backup_tablespaces("test", "t33");
 EOF
 UNLOCK TABLES;
 DROP TABLE t33;
-CREATE TABLE t33 (
+eval CREATE TABLE t33 (
 a BIGINT NOT NULL PRIMARY KEY,
-b BIGINT NOT NULL AUTO_INCREMENT,
-KEY(b)) ENGINE = InnoDB;
+b BIGINT NOT NULL $AUTO_INCREMENT_KEY_b) ENGINE = InnoDB;
 ALTER TABLE t33 DISCARD TABLESPACE;
 perl;
 do "$ENV{MTR_SUITE_DIR}/include/innodb-util.pl";
diff --git a/mysql-test/suite/innodb/t/innodb-index.test b/mysql-test/suite/innodb/t/innodb-index.test
index c7aa6250da5..03cbb5aef9d 100644
--- a/mysql-test/suite/innodb/t/innodb-index.test
+++ b/mysql-test/suite/innodb/t/innodb-index.test
@@ -1193,6 +1193,48 @@ SHOW CREATE TABLE t;
 --disable_prepare_warnings
 DROP TABLE t;
 
+--echo #
+--echo #  MDEV-27374  InnoDB table becomes corrupt after renaming DESC-indexed column
+--echo #
+CREATE TABLE t1 (a VARCHAR(8), PRIMARY KEY(a DESC)) ENGINE=InnoDB;
+ALTER TABLE t1 RENAME COLUMN a TO b, ALGORITHM=INPLACE;
+SELECT TABLE_ID INTO @table_id FROM INFORMATION_SCHEMA.INNODB_SYS_TABLES WHERE NAME="test/t1";
+SELECT INDEX_ID INTO @index_id FROM INFORMATION_SCHEMA.INNODB_SYS_INDEXES WHERE TABLE_ID = @table_id;
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_SYS_FIELDS WHERE INDEX_ID=@index_id;
+DROP TABLE t1;
+
+--echo #
+--echo #  MDEV-27432 ASC/DESC primary and unique keys cause index
+--echo #	inconsistency between InnoDB and server
+--echo #
+CREATE TABLE t1 (id INT NOT NULL, UNIQUE(id DESC)) ENGINE=InnoDB;
+ALTER TABLE t1 ADD PRIMARY KEY (id), ALGORITHM=INPLACE;
+SHOW CREATE TABLE t1;
+DROP TABLE t1;
+
+--echo #
+--echo #  MDEV-27445 Index inconsistency and assertion failure after
+--echo #	renaming virtual column with DESC key
+--echo #
+CREATE TABLE t1(a INT, b INT AS (a), KEY(a, b DESC)) ENGINE=InnoDB;
+ALTER TABLE t1 RENAME COLUMN IF EXISTS b TO v;
+ALTER TABLE t1 FORCE;
+DROP TABLE t1;
+
+--echo #
+--echo #  MDEV-27592 DESC primary index fails to set wide format
+--echo #	while renaming the column
+--echo #
+CREATE TABLE t1 (id INT PRIMARY KEY, a CHAR(8), b INT, KEY(a DESC,b)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (1,'foo',10);
+ALTER TABLE t1 RENAME COLUMN b TO c, ALGORITHM=INPLACE;
+SELECT TABLE_ID INTO @table_id FROM INFORMATION_SCHEMA.INNODB_SYS_TABLES WHERE NAME="test/t1";
+SELECT INDEX_ID INTO @index_id FROM INFORMATION_SCHEMA.INNODB_SYS_INDEXES WHERE TABLE_ID = @table_id ORDER BY INDEX_ID DESC LIMIT 1;
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_SYS_FIELDS WHERE INDEX_ID=@index_id;
+DROP TABLE t1;
+
+--echo # End of 10.8 tests
+
 --disable_query_log
 
 call mtr.add_suppression("InnoDB: Tablespace .* was not found at .*t[12].ibd.");
diff --git a/mysql-test/suite/innodb_fts/r/create.result b/mysql-test/suite/innodb_fts/r/create.result
index 3ca24f5253d..7be9333e647 100644
--- a/mysql-test/suite/innodb_fts/r/create.result
+++ b/mysql-test/suite/innodb_fts/r/create.result
@@ -187,4 +187,16 @@ FTS_DOC_ID bigint unsigned not null,
 unique key FTS_DOC_ID_INDEX(FTS_DOC_ID, f1),
 fulltext (f2))
 engine=innodb;
-ERROR 42000: Incorrect index name 'FTS_DOC_ID_INDEX'
+ERROR HY000: Index 'FTS_DOC_ID_INDEX' is of wrong type for an InnoDB FULLTEXT index
+#
+# MDEV-26938 Support descending indexes internally in InnoDB
+#
+CREATE TABLE t1(a INT PRIMARY KEY, b TEXT, FTS_DOC_ID BIGINT UNSIGNED NOT NULL,
+UNIQUE KEY FTS_DOC_ID_INDEX(FTS_DOC_ID DESC), FULLTEXT(b))
+ENGINE=InnoDB;
+DROP TABLE t1;
+CREATE TABLE t1(a INT PRIMARY KEY, b TEXT, FTS_DOC_ID BIGINT UNSIGNED NOT NULL,
+UNIQUE KEY FTS_DOC_ID_INDEX(FTS_DOC_ID DESC)) ENGINE=InnoDB;
+ALTER TABLE t1 ADD FULLTEXT INDEX(b), ALGORITHM=INPLACE;
+ALTER TABLE t1 ADD FULLTEXT INDEX(b), ALGORITHM=COPY;
+DROP TABLE t1;
diff --git a/mysql-test/suite/innodb_fts/t/create.test b/mysql-test/suite/innodb_fts/t/create.test
index 38c93de4982..6f5da11a66c 100644
--- a/mysql-test/suite/innodb_fts/t/create.test
+++ b/mysql-test/suite/innodb_fts/t/create.test
@@ -110,10 +110,29 @@ SET GLOBAL innodb_optimize_fulltext_only= @optimize_fulltext.save;
 --echo #
 --echo # MDEV-24403 Segfault on CREATE TABLE with explicit FTS_DOC_ID_INDEX by multiple fields
 --echo #
---error ER_WRONG_NAME_FOR_INDEX
+--error ER_INNODB_FT_WRONG_DOCID_INDEX
 create table t1 (
   f1 int, f2 text,
   FTS_DOC_ID bigint unsigned not null,
   unique key FTS_DOC_ID_INDEX(FTS_DOC_ID, f1),
   fulltext (f2))
 engine=innodb;
+
+--echo #
+--echo # MDEV-26938 Support descending indexes internally in InnoDB
+--echo #
+
+# Unfortunately, the HA_REVERSE_SORT flag is not being stored in the .frm file.
+#FIXME: --error ER_INNODB_FT_WRONG_DOCID_INDEX
+CREATE TABLE t1(a INT PRIMARY KEY, b TEXT, FTS_DOC_ID BIGINT UNSIGNED NOT NULL,
+                UNIQUE KEY FTS_DOC_ID_INDEX(FTS_DOC_ID DESC), FULLTEXT(b))
+ENGINE=InnoDB;
+DROP TABLE t1;
+
+CREATE TABLE t1(a INT PRIMARY KEY, b TEXT, FTS_DOC_ID BIGINT UNSIGNED NOT NULL,
+                UNIQUE KEY FTS_DOC_ID_INDEX(FTS_DOC_ID DESC)) ENGINE=InnoDB;
+#FIXME: --error ER_INNODB_FT_WRONG_DOCID_INDEX
+ALTER TABLE t1 ADD FULLTEXT INDEX(b), ALGORITHM=INPLACE;
+#FIXME: --error ER_INNODB_FT_WRONG_DOCID_INDEX
+ALTER TABLE t1 ADD FULLTEXT INDEX(b), ALGORITHM=COPY;
+DROP TABLE t1;
diff --git a/storage/innobase/CMakeLists.txt b/storage/innobase/CMakeLists.txt
index a2ea7c24541..af46ff9e687 100644
--- a/storage/innobase/CMakeLists.txt
+++ b/storage/innobase/CMakeLists.txt
@@ -203,7 +203,6 @@ SET(INNOBASE_SOURCES
 	include/que0types.h
 	include/read0types.h
 	include/rem0cmp.h
-	include/rem0cmp.ic
 	include/rem0rec.h
 	include/rem0rec.ic
 	include/rem0types.h
diff --git a/storage/innobase/btr/btr0btr.cc b/storage/innobase/btr/btr0btr.cc
index bd18fd2d45f..08a0ae55793 100644
--- a/storage/innobase/btr/btr0btr.cc
+++ b/storage/innobase/btr/btr0btr.cc
@@ -2228,7 +2228,8 @@ btr_page_insert_fits(
 		rec = page_rec_get_next(page_get_infimum_rec(page));
 		end_rec = page_rec_get_next(btr_cur_get_rec(cursor));
 
-	} else if (cmp_dtuple_rec(tuple, split_rec, *offsets) >= 0) {
+	} else if (cmp_dtuple_rec(tuple, split_rec, cursor->index,
+				  *offsets) >= 0) {
 
 		rec = page_rec_get_next(page_get_infimum_rec(page));
 		end_rec = split_rec;
@@ -2514,7 +2515,7 @@ btr_page_tuple_smaller(
 				   ? cursor->index->n_core_fields : 0,
 				   n_uniq, heap);
 
-	return(cmp_dtuple_rec(tuple, first_rec, *offsets) < 0);
+	return cmp_dtuple_rec(tuple, first_rec, cursor->index, *offsets) < 0;
 }
 
 /** Insert the tuple into the right sibling page, if the cursor is at the end
@@ -2804,7 +2805,8 @@ func_start:
 					   n_uniq, heap);
 
 		insert_left = !tuple
-			|| cmp_dtuple_rec(tuple, split_rec, *offsets) < 0;
+			|| cmp_dtuple_rec(tuple, split_rec, cursor->index,
+					  *offsets) < 0;
 
 		if (!insert_left && new_page_zip && n_iterations > 0) {
 			/* If a compressed page has already been split,
@@ -4233,7 +4235,8 @@ btr_check_node_ptr(
 			tuple, btr_cur_get_rec(&cursor),
 			PAGE_CUR_WITHIN));
 	} else {
-		ut_a(!cmp_dtuple_rec(tuple, btr_cur_get_rec(&cursor), offsets));
+		ut_a(!cmp_dtuple_rec(tuple, btr_cur_get_rec(&cursor), index,
+				     offsets));
 	}
 func_exit:
 	mem_heap_free(heap);
@@ -4731,7 +4734,7 @@ loop:
 		/* For spatial index, we cannot guarantee the key ordering
 		across pages, so skip the record compare verification for
 		now. Will enhanced in special R-Tree index validation scheme */
-		if (!dict_index_is_spatial(index)
+		if (index->is_btree()
 		    && cmp_rec_rec(rec, right_rec,
 				   offsets, offsets2, index) >= 0) {
 
@@ -4766,9 +4769,7 @@ loop:
 	in parent level and linked pages in the child level.
 	2) Search parent from root is very costly for R-tree.
 	We will add special validation mechanism for R-tree later (WL #7520) */
-	if (!dict_index_is_spatial(index)
-	    && block->page.id().page_no() != dict_index_get_page(index)) {
-
+	if (index->is_btree() && block->page.id().page_no() != index->page) {
 		/* Check father node pointers */
 		rec_t*	node_ptr;
 
@@ -4825,7 +4826,7 @@ loop:
 				page_rec_get_next(page_get_infimum_rec(page)),
 				0, heap, btr_page_get_level(page));
 
-			if (cmp_dtuple_rec(node_ptr_tuple, node_ptr,
+			if (cmp_dtuple_rec(node_ptr_tuple, node_ptr, index,
 					   offsets)) {
 				const rec_t* first_rec = page_rec_get_next(
 					page_get_infimum_rec(page));
diff --git a/storage/innobase/btr/btr0cur.cc b/storage/innobase/btr/btr0cur.cc
index ceac301a502..5f6562e5394 100644
--- a/storage/innobase/btr/btr0cur.cc
+++ b/storage/innobase/btr/btr0cur.cc
@@ -1411,7 +1411,7 @@ btr_cur_search_to_nth_level_func(
 # endif /* PAGE_CUR_LE_OR_EXTENDS */
 	    && info->last_hash_succ
 	    && !(tuple->info_bits & REC_INFO_MIN_REC_FLAG)
-	    && !index->is_spatial() && !index->table->is_temporary()
+	    && index->is_btree() && !index->table->is_temporary()
 	    && btr_search_guess_on_hash(index, info, tuple, mode,
 					latch_mode, cursor,
 					ahi_latch, mtr)) {
@@ -1636,7 +1636,6 @@ retry_page_get:
 		case BTR_INSERT_OP:
 		case BTR_INSERT_IGNORE_UNIQUE_OP:
 			ut_ad(buf_mode == BUF_GET_IF_IN_POOL);
-			ut_ad(!dict_index_is_spatial(index));
 
 			if (ibuf_insert(IBUF_OP_INSERT, tuple, index,
 					page_id, zip_size, cursor->thr)) {
@@ -1649,7 +1648,6 @@ retry_page_get:
 
 		case BTR_DELMARK_OP:
 			ut_ad(buf_mode == BUF_GET_IF_IN_POOL);
-			ut_ad(!dict_index_is_spatial(index));
 
 			if (ibuf_insert(IBUF_OP_DELETE_MARK, tuple,
 					index, page_id, zip_size,
@@ -1664,7 +1662,7 @@ retry_page_get:
 
 		case BTR_DELETE_OP:
 			ut_ad(buf_mode == BUF_GET_IF_IN_POOL_OR_WATCH);
-			ut_ad(!dict_index_is_spatial(index));
+			ut_ad(index->is_btree());
 			auto& chain = buf_pool.page_hash.cell_get(
 				page_id.fold());
 
@@ -1959,9 +1957,8 @@ retry_page_get:
 				DICT_INDEX_SPATIAL_NODEPTR_SIZE + 1;
 		}
 #ifdef BTR_CUR_HASH_ADAPT
-	} else if (height == 0 && btr_search_enabled
-		   && !(tuple->info_bits & REC_INFO_MIN_REC_FLAG)
-		   && !dict_index_is_spatial(index)) {
+	} else if (height == 0 && index->is_btree() && btr_search_enabled
+		   && !(tuple->info_bits & REC_INFO_MIN_REC_FLAG)) {
 		/* The adaptive hash index is only used when searching
 		for leaf pages (height==0), but not in r-trees.
 		We only need the byte prefix comparison for the purpose
diff --git a/storage/innobase/btr/btr0pcur.cc b/storage/innobase/btr/btr0pcur.cc
index ac91f87c8e1..9c32236db9c 100644
--- a/storage/innobase/btr/btr0pcur.cc
+++ b/storage/innobase/btr/btr0pcur.cc
@@ -430,7 +430,7 @@ btr_pcur_restore_position(
 	rec_offs_init(offsets);
 	if (cursor->rel_pos == BTR_PCUR_ON
 	    && btr_pcur_is_on_user_rec(cursor)
-	    && !cmp_dtuple_rec(tuple, btr_pcur_get_rec(cursor),
+	    && !cmp_dtuple_rec(tuple, btr_pcur_get_rec(cursor), index,
 			       rec_get_offsets(btr_pcur_get_rec(cursor),
 					       index, offsets,
 					       index->n_core_fields,
diff --git a/storage/innobase/btr/btr0sea.cc b/storage/innobase/btr/btr0sea.cc
index 96bbd8af3c1..6589c72ac4a 100644
--- a/storage/innobase/btr/btr0sea.cc
+++ b/storage/innobase/btr/btr0sea.cc
@@ -796,7 +796,8 @@ btr_search_check_guess(
 	offsets = rec_get_offsets(rec, cursor->index, offsets,
 				  cursor->index->n_core_fields,
 				  n_unique, &heap);
-	cmp = cmp_dtuple_rec_with_match(tuple, rec, offsets, &match);
+	cmp = cmp_dtuple_rec_with_match(tuple, rec, cursor->index, offsets,
+					&match);
 
 	if (mode == PAGE_CUR_GE) {
 		if (cmp > 0) {
@@ -848,7 +849,7 @@ btr_search_check_guess(
 					  cursor->index->n_core_fields,
 					  n_unique, &heap);
 		cmp = cmp_dtuple_rec_with_match(
-			tuple, prev_rec, offsets, &match);
+			tuple, prev_rec, cursor->index, offsets, &match);
 		if (mode == PAGE_CUR_GE) {
 			success = cmp > 0;
 		} else {
@@ -872,7 +873,7 @@ btr_search_check_guess(
 					  cursor->index->n_core_fields,
 					  n_unique, &heap);
 		cmp = cmp_dtuple_rec_with_match(
-			tuple, next_rec, offsets, &match);
+			tuple, next_rec, cursor->index, offsets, &match);
 		if (mode == PAGE_CUR_LE) {
 			success = cmp < 0;
 			cursor->up_match = match;
diff --git a/storage/innobase/data/data0data.cc b/storage/innobase/data/data0data.cc
index 13efd7f3665..e63ba450ea1 100644
--- a/storage/innobase/data/data0data.cc
+++ b/storage/innobase/data/data0data.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1994, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2020, MariaDB Corporation.
+Copyright (c) 2017, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -79,40 +79,6 @@ void dtuple_t::trim(const dict_index_t& index)
 	n_fields = i;
 }
 
-/** Compare two data tuples.
-@param[in] tuple1 first data tuple
-@param[in] tuple2 second data tuple
-@return positive, 0, negative if tuple1 is greater, equal, less, than tuple2,
-respectively */
-int
-dtuple_coll_cmp(
-	const dtuple_t*	tuple1,
-	const dtuple_t*	tuple2)
-{
-	ulint	n_fields;
-	ulint	i;
-	int	cmp;
-
-	ut_ad(tuple1 != NULL);
-	ut_ad(tuple2 != NULL);
-	ut_ad(tuple1->magic_n == DATA_TUPLE_MAGIC_N);
-	ut_ad(tuple2->magic_n == DATA_TUPLE_MAGIC_N);
-	ut_ad(dtuple_check_typed(tuple1));
-	ut_ad(dtuple_check_typed(tuple2));
-
-	n_fields = dtuple_get_n_fields(tuple1);
-
-	cmp = (int) n_fields - (int) dtuple_get_n_fields(tuple2);
-
-	for (i = 0; cmp == 0 && i < n_fields; i++) {
-		const dfield_t*	field1	= dtuple_get_nth_field(tuple1, i);
-		const dfield_t*	field2	= dtuple_get_nth_field(tuple2, i);
-		cmp = cmp_dfield_dfield(field1, field2);
-	}
-
-	return(cmp);
-}
-
 /*********************************************************************//**
 Sets number of fields used in a tuple. Normally this is set in
 dtuple_create, but if you want later to set it smaller, you can use this. */
diff --git a/storage/innobase/dict/dict0crea.cc b/storage/innobase/dict/dict0crea.cc
index f1bc2fcd980..68bb2c44d3f 100644
--- a/storage/innobase/dict/dict0crea.cc
+++ b/storage/innobase/dict/dict0crea.cc
@@ -536,15 +536,15 @@ dict_create_sys_fields_tuple(
 	dict_field_t*	field;
 	dfield_t*	dfield;
 	byte*		ptr;
-	ibool		index_contains_column_prefix_field	= FALSE;
-	ulint		j;
+	bool		wide_pos = false;
 
 	ut_ad(index);
 	ut_ad(heap);
 
-	for (j = 0; j < index->n_fields; j++) {
-		if (dict_index_get_nth_field(index, j)->prefix_len > 0) {
-			index_contains_column_prefix_field = TRUE;
+	for (unsigned j = 0; j < index->n_fields; j++) {
+		const dict_field_t* f = dict_index_get_nth_field(index, j);
+		if (f->prefix_len || f->descending) {
+			wide_pos = true;
 			break;
 		}
 	}
@@ -569,12 +569,15 @@ dict_create_sys_fields_tuple(
 
 	ptr = static_cast<byte*>(mem_heap_alloc(heap, 4));
 
-	if (index_contains_column_prefix_field) {
-		/* If there are column prefix fields in the index, then
-		we store the number of the field to the 2 HIGH bytes
-		and the prefix length to the 2 low bytes, */
-
-		mach_write_to_4(ptr, (fld_no << 16) + field->prefix_len);
+	if (wide_pos) {
+		/* If there are column prefixes or columns with
+		descending order in the index, then we write the
+		field number to the 16 most significant bits,
+		the DESC flag to bit 15, and the prefix length
+		in the 15 least significant bits. */
+		mach_write_to_4(ptr, (fld_no << 16)
+				| (!!field->descending) << 15
+				| field->prefix_len);
 	} else {
 		/* Else we store the number of the field to the 2 LOW bytes.
 		This is to keep the storage format compatible with
diff --git a/storage/innobase/dict/dict0dict.cc b/storage/innobase/dict/dict0dict.cc
index a990a518d5b..54172b9a408 100644
--- a/storage/innobase/dict/dict0dict.cc
+++ b/storage/innobase/dict/dict0dict.cc
@@ -2,7 +2,7 @@
 
 Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2012, Facebook Inc.
-Copyright (c) 2013, 2021, MariaDB Corporation.
+Copyright (c) 2013, 2022, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -1233,7 +1233,7 @@ static bool dict_table_can_be_evicted(dict_table_t *table)
 dict_index_t *dict_index_t::clone() const
 {
   ut_ad(n_fields);
-  ut_ad(!(type & (DICT_IBUF | DICT_SPATIAL | DICT_FTS)));
+  ut_ad(is_btree());
   ut_ad(online_status == ONLINE_INDEX_COMPLETE);
   ut_ad(is_committed());
   ut_ad(!is_dummy);
@@ -2253,15 +2253,14 @@ found:
 	return(TRUE);
 }
 
-/*******************************************************************//**
-Adds a column to index. */
-void
-dict_index_add_col(
-/*===============*/
-	dict_index_t*		index,		/*!< in/out: index */
-	const dict_table_t*	table,		/*!< in: table */
-	dict_col_t*		col,		/*!< in: column */
-	ulint			prefix_len)	/*!< in: column prefix length */
+/** Add a column to an index.
+@param index          index
+@param table          table
+@param col            column
+@param prefix_len     column prefix length
+@param descending     whether to use descending order */
+void dict_index_add_col(dict_index_t *index, const dict_table_t *table,
+                        dict_col_t *col, ulint prefix_len, bool descending)
 {
 	dict_field_t*	field;
 	const char*	col_name;
@@ -2299,6 +2298,8 @@ dict_index_add_col(
 		field->fixed_len = 0;
 	}
 
+	field->descending = descending;
+
 	/* The comparison limit above must be constant.  If it were
 	changed, the disk format of some fixed-length columns would
 	change, which would be a disaster. */
@@ -2330,7 +2331,7 @@ dict_index_copy(
 		field = dict_index_get_nth_field(index2, i);
 
 		dict_index_add_col(index1, index2->table, field->col,
-				   field->prefix_len);
+				   field->prefix_len, field->descending);
 	}
 }
 
@@ -2644,17 +2645,12 @@ dict_index_build_internal_non_clust(
 	index entry uniquely */
 
 	for (i = 0; i < clust_index->n_uniq; i++) {
-
 		field = dict_index_get_nth_field(clust_index, i);
 
-		if (!indexed[field->col->ind]) {
-			dict_index_add_col(new_index, table, field->col,
-					   field->prefix_len);
-		} else if (dict_index_is_spatial(index)) {
-			/*For spatial index, we still need to add the
-			field to index. */
+		if (!indexed[field->col->ind] || index->is_spatial()) {
 			dict_index_add_col(new_index, table, field->col,
-					   field->prefix_len);
+					   field->prefix_len,
+					   field->descending);
 		}
 	}
 
@@ -4724,7 +4720,7 @@ dict_foreign_qualify_index(
 		return(false);
 	}
 
-	if (index->type & (DICT_SPATIAL | DICT_FTS | DICT_CORRUPT)) {
+	if (!index->is_btree()) {
 		return false;
 	}
 
diff --git a/storage/innobase/dict/dict0load.cc b/storage/innobase/dict/dict0load.cc
index 20ab06c8461..0b73e8452a6 100644
--- a/storage/innobase/dict/dict0load.cc
+++ b/storage/innobase/dict/dict0load.cc
@@ -1467,6 +1467,7 @@ dict_load_field_low(
 	ulint		len;
 	unsigned	pos_and_prefix_len;
 	unsigned	prefix_len;
+	bool		descending;
 	bool		first_field;
 	ulint		position;
 
@@ -1522,10 +1523,12 @@ err_len:
 	}
 
 	if (first_field || pos_and_prefix_len > 0xFFFFUL) {
-		prefix_len = pos_and_prefix_len & 0xFFFFUL;
+		prefix_len = pos_and_prefix_len & 0x7FFFUL;
+		descending = (pos_and_prefix_len & 0x8000UL);
 		position = (pos_and_prefix_len & 0xFFFF0000UL)  >> 16;
 	} else {
 		prefix_len = 0;
+		descending = false;
 		position = pos_and_prefix_len & 0xFFFFUL;
 	}
 
@@ -1549,7 +1552,7 @@ err_len:
 	if (index) {
 		dict_mem_index_add_field(
 			index, mem_heap_strdupl(heap, (const char*) field, len),
-			prefix_len);
+			prefix_len, descending);
 	} else {
 		ut_a(sys_field);
 		ut_a(pos);
@@ -1557,6 +1560,7 @@ err_len:
 		sys_field->name = mem_heap_strdupl(
 			heap, (const char*) field, len);
 		sys_field->prefix_len = prefix_len & ((1U << 12) - 1);
+		sys_field->descending = descending;
 		*pos = position;
 	}
 
@@ -2966,13 +2970,12 @@ loop:
 	following call does the comparison in the latin1_swedish_ci
 	charset-collation, in a case-insensitive way. */
 
-	if (0 != cmp_data_data(dfield_get_type(dfield)->mtype,
-			       dfield_get_type(dfield)->prtype,
-			       static_cast<const byte*>(
-				       dfield_get_data(dfield)),
-			       dfield_get_len(dfield),
-			       field, len)) {
-
+	if (cmp_data(dfield_get_type(dfield)->mtype,
+		     dfield_get_type(dfield)->prtype,
+		     false,
+		     static_cast<const byte*>(dfield_get_data(dfield)),
+		     dfield_get_len(dfield),
+		     field, len)) {
 		goto load_next_index;
 	}
 
diff --git a/storage/innobase/dict/dict0mem.cc b/storage/innobase/dict/dict0mem.cc
index 1a8d5764d0f..10e225941a1 100644
--- a/storage/innobase/dict/dict0mem.cc
+++ b/storage/innobase/dict/dict0mem.cc
@@ -1046,32 +1046,6 @@ dict_mem_table_free_foreign_vcol_set(
 }
 
 /**********************************************************************//**
-Adds a field definition to an index. NOTE: does not take a copy
-of the column name if the field is a column. The memory occupied
-by the column name may be released only after publishing the index. */
-void
-dict_mem_index_add_field(
-/*=====================*/
-	dict_index_t*	index,		/*!< in: index */
-	const char*	name,		/*!< in: column name */
-	ulint		prefix_len)	/*!< in: 0 or the column prefix length
-					in a MySQL index like
-					INDEX (textcol(25)) */
-{
-	dict_field_t*	field;
-
-	ut_ad(index);
-	ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);
-
-	index->n_def++;
-
-	field = dict_index_get_nth_field(index, unsigned(index->n_def) - 1);
-
-	field->name = name;
-	field->prefix_len = prefix_len & ((1U << 12) - 1);
-}
-
-/**********************************************************************//**
 Frees an index memory object. */
 void
 dict_mem_index_free(
diff --git a/storage/innobase/dict/dict0stats.cc b/storage/innobase/dict/dict0stats.cc
index fd744e6e2f5..b406028aa87 100644
--- a/storage/innobase/dict/dict0stats.cc
+++ b/storage/innobase/dict/dict0stats.cc
@@ -1123,7 +1123,7 @@ btr_estimate_number_of_different_key_vals(dict_index_t* index,
 
 	std::vector<index_field_stats_t> result;
 
-	ut_ad(!index->is_spatial());
+	ut_ad(index->is_btree());
 
 	n_cols = dict_index_get_n_unique(index);
 
@@ -1515,7 +1515,7 @@ dict_stats_update_transient(
 
 		ut_ad(!dict_index_is_ibuf(index));
 
-		if (index->type & (DICT_FTS | DICT_SPATIAL)) {
+		if (!index->is_btree()) {
 			continue;
 		}
 
@@ -2510,8 +2510,7 @@ static index_stats_t dict_stats_analyze_index(dict_index_t* index)
 	ut_ad(!index->table->stats_mutex_is_owner());
 	ut_ad(index->table->get_ref_count());
 
-	/* Disable update statistic for Rtree */
-	if (dict_index_is_spatial(index)) {
+	if (!index->is_btree()) {
 		DBUG_RETURN(result);
 	}
 
@@ -2869,9 +2868,7 @@ dict_stats_update_persistent(
 	     index != NULL;
 	     index = dict_table_get_next_index(index)) {
 
-		ut_ad(!dict_index_is_ibuf(index));
-
-		if (index->type & (DICT_FTS | DICT_SPATIAL)) {
+		if (!index->is_btree()) {
 			continue;
 		}
 
diff --git a/storage/innobase/eval/eval0eval.cc b/storage/innobase/eval/eval0eval.cc
index 73ab113cff5..bafb0b55d09 100644
--- a/storage/innobase/eval/eval0eval.cc
+++ b/storage/innobase/eval/eval0eval.cc
@@ -144,8 +144,8 @@ eval_cmp_like(
 	switch (op) {
 	case IB_LIKE_PREFIX:
 		arg4 = que_node_get_next(arg3);
-		return(!cmp_dfield_dfield_like_prefix(que_node_get_val(arg1),
-						      que_node_get_val(arg4)));
+		return(cmp_dfield_dfield_eq_prefix(que_node_get_val(arg1),
+						   que_node_get_val(arg4)));
 	case IB_LIKE_EXACT:
 		return(!cmp_dfield_dfield(que_node_get_val(arg1),
 					  que_node_get_val(arg2)));
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index f79e58523f6..56250ea5486 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -5406,6 +5406,11 @@ innobase_match_index_columns(
 			col_type= DATA_FIXBINARY;
 		}
 
+		if (innodb_idx_fld->descending
+		    != !!(key_part->key_part_flag & HA_REVERSE_SORT)) {
+			DBUG_RETURN(FALSE);
+		}
+
 		if (col_type != mtype) {
 			/* If the col_type we get from mysql type is a geometry
 			data type, we should check if mtype is a legacy type
@@ -10830,7 +10835,9 @@ create_index(
 			}
 
 			dict_mem_index_add_field(index, field->field_name.str,
-						 0);
+						 0,
+						 key->key_part->key_part_flag
+						 & HA_REVERSE_SORT);
 		}
 
 		DBUG_RETURN(convert_error_code_to_mysql(
@@ -10924,7 +10931,9 @@ create_index(
 			index->type |= DICT_VIRTUAL;
 		}
 
-		dict_mem_index_add_field(index, field_name, prefix_len);
+		dict_mem_index_add_field(index, field_name, prefix_len,
+					 key_part->key_part_flag
+					 & HA_REVERSE_SORT);
 	}
 
 	ut_ad(key->flags & HA_FULLTEXT || !(index->type & DICT_FTS));
@@ -11484,6 +11493,8 @@ bool create_table_info_t::innobase_table_flags()
 
 		/* Do a pre-check on FTS DOC ID index */
 		if (!(key->flags & HA_NOSAME)
+		    || key->user_defined_key_parts != 1
+		    || (key->key_part[0].key_part_flag & HA_REVERSE_SORT)
 		    || strcmp(key->name.str, FTS_DOC_ID_INDEX_NAME)
 		    || strcmp(key->key_part[0].field->field_name.str,
 			      FTS_DOC_ID_COL_NAME)) {
diff --git a/storage/innobase/handler/handler0alter.cc b/storage/innobase/handler/handler0alter.cc
index 075239306b0..c92fb447c3d 100644
--- a/storage/innobase/handler/handler0alter.cc
+++ b/storage/innobase/handler/handler0alter.cc
@@ -3600,6 +3600,8 @@ innobase_create_index_field_def(
 		index_field->col_no = key_part->fieldnr - num_v;
 	}
 
+	index_field->descending= !!(key_part->key_part_flag & HA_REVERSE_SORT);
+
 	if (DATA_LARGE_MTYPE(col_type)
 	    || (key_part->length < field->pack_length()
 		&& field->type() != MYSQL_TYPE_VARCHAR)
@@ -3701,6 +3703,7 @@ innobase_create_index_def(
 		index->fields[0].col_no = key->key_part[0].fieldnr - num_v;
 		index->fields[0].prefix_len = 0;
 		index->fields[0].is_v_col = false;
+		index->fields[0].descending = false;
 
 		/* Currently, the spatial index cannot be created
 		on virtual columns. It is blocked in the SQL layer. */
@@ -3756,6 +3759,8 @@ innobase_fts_check_doc_id_index(
 
 			if ((key.flags & HA_NOSAME)
 			    && key.user_defined_key_parts == 1
+			    && !(key.key_part[0].key_part_flag
+				 & HA_REVERSE_SORT)
 			    && !strcmp(key.name.str, FTS_DOC_ID_INDEX_NAME)
 			    && !strcmp(key.key_part[0].field->field_name.str,
 				       FTS_DOC_ID_COL_NAME)) {
@@ -3785,7 +3790,7 @@ innobase_fts_check_doc_id_index(
 		}
 
 		if (!dict_index_is_unique(index)
-		    || dict_index_get_n_unique(index) > 1
+		    || dict_index_get_n_unique(index) != 1
 		    || strcmp(index->name, FTS_DOC_ID_INDEX_NAME)) {
 			return(FTS_INCORRECT_DOC_ID_INDEX);
 		}
@@ -3796,6 +3801,7 @@ innobase_fts_check_doc_id_index(
 
 		/* The column would be of a BIGINT data type */
 		if (strcmp(field->name, FTS_DOC_ID_COL_NAME) == 0
+		    && !field->descending
 		    && field->col->mtype == DATA_INT
 		    && field->col->len == 8
 		    && field->col->prtype & DATA_NOT_NULL
@@ -3837,6 +3843,7 @@ innobase_fts_check_doc_id_index_in_def(
 		named as "FTS_DOC_ID_INDEX" and on column "FTS_DOC_ID" */
 		if (!(key->flags & HA_NOSAME)
 		    || key->user_defined_key_parts != 1
+		    || (key->key_part[0].key_part_flag & HA_REVERSE_SORT)
 		    || strcmp(key->name.str, FTS_DOC_ID_INDEX_NAME)
 		    || strcmp(key->key_part[0].field->field_name.str,
 			      FTS_DOC_ID_COL_NAME)) {
@@ -4034,6 +4041,7 @@ created_clustered:
 		index->n_fields = 1;
 		index->fields->col_no = fts_doc_id_col;
 		index->fields->prefix_len = 0;
+		index->fields->descending = false;
 		index->fields->is_v_col = false;
 		index->ind_type = DICT_UNIQUE;
 		ut_ad(!rebuild
@@ -4643,7 +4651,8 @@ columns are removed from the PK;
 (3) Changing the order of existing PK columns;
 (4) Decreasing the prefix length just like removing existing PK columns
 follows rule(1), Increasing the prefix length just like adding existing
-PK columns follows rule(2).
+PK columns follows rule(2);
+(5) Changing the ASC/DESC attribute of the existing PK columns.
 @param[in]	col_map		mapping of old column numbers to new ones
 @param[in]	ha_alter_info	Data used during in-place alter
 @param[in]	old_clust_index	index to be compared
@@ -4736,10 +4745,16 @@ innobase_pk_order_preserved(
 			continue;
 		}
 
+		const dict_field_t &of = old_clust_index->fields[old_field];
+		const dict_field_t &nf = new_clust_index->fields[new_field];
+
+		if (of.descending != nf.descending) {
+			return false;
+		}
+
 		/* Check prefix length change. */
 		const lint	prefix_change = innobase_pk_col_prefix_compare(
-			new_clust_index->fields[new_field].prefix_len,
-			old_clust_index->fields[old_field].prefix_len);
+			nf.prefix_len, of.prefix_len);
 
 		if (prefix_change < 0) {
 			/* If a column's prefix length is decreased, it should
@@ -8923,7 +8938,7 @@ innobase_rename_column_try(
 	const char*			to)
 {
 	dberr_t		error;
-	bool clust_has_prefixes = false;
+	bool clust_has_wide_format = false;
 
 	DBUG_ENTER("innobase_rename_column_try");
 
@@ -8944,10 +8959,11 @@ innobase_rename_column_try(
 	     index != NULL;
 	     index = dict_table_get_next_index(index)) {
 
-		bool has_prefixes = false;
+		bool wide_format = false;
 		for (size_t i = 0; i < dict_index_get_n_fields(index); i++) {
-			if (dict_index_get_nth_field(index, i)->prefix_len) {
-				has_prefixes = true;
+			dict_field_t* field= dict_index_get_nth_field(index, i);
+			if (field->prefix_len || field->descending) {
+				wide_format = true;
 				break;
 			}
 		}
@@ -8962,8 +8978,10 @@ innobase_rename_column_try(
 			}
 
 			pars_info_t* info = pars_info_create();
-			ulint pos = has_prefixes ? i << 16 | f.prefix_len : i;
-
+			ulint pos = wide_format
+				    ? i << 16 | f.prefix_len
+				      | !!f.descending << 15
+				    : i;
 			pars_info_add_ull_literal(info, "indexid", index->id);
 			pars_info_add_int4_literal(info, "nth", pos);
 			pars_info_add_str_literal(info, "new", to);
@@ -8983,15 +9001,16 @@ innobase_rename_column_try(
 				goto err_exit;
 			}
 
-			if (!has_prefixes || !clust_has_prefixes
-			    || f.prefix_len) {
+			if (!wide_format || !clust_has_wide_format
+			    || f.prefix_len || f.descending) {
 				continue;
 			}
 
 			/* For secondary indexes, the
-			has_prefixes check can be 'polluted'
-			by PRIMARY KEY column prefix. Try also
-			the simpler encoding of SYS_FIELDS.POS. */
+			wide_format check can be 'polluted'
+			by PRIMARY KEY column prefix or descending
+			field. Try also the simpler encoding
+			of SYS_FIELDS.POS. */
 			info = pars_info_create();
 
 			pars_info_add_ull_literal(info, "indexid", index->id);
@@ -9013,7 +9032,7 @@ innobase_rename_column_try(
 		}
 
 		if (index == dict_table_get_first_index(ctx.old_table)) {
-			clust_has_prefixes = has_prefixes;
+			clust_has_wide_format = wide_format;
 		}
 	}
 
diff --git a/storage/innobase/ibuf/ibuf0ibuf.cc b/storage/innobase/ibuf/ibuf0ibuf.cc
index f41e3f659fc..413d0ccef90 100644
--- a/storage/innobase/ibuf/ibuf0ibuf.cc
+++ b/storage/innobase/ibuf/ibuf0ibuf.cc
@@ -1657,6 +1657,7 @@ ibuf_entry_build(
 		dfield_copy(field, entry_field);
 
 		ifield = dict_index_get_nth_field(index, i);
+		ut_ad(!ifield->descending);
 		/* Prefix index columns of fixed-length columns are of
 		fixed length.  However, in the function call below,
 		dfield_get_type(entry_field) contains the fixed length
@@ -3491,7 +3492,7 @@ ibuf_insert(
 
 	ut_ad(dtuple_check_typed(entry));
 	ut_ad(page_id.space() != SRV_TMP_SPACE_ID);
-
+	ut_ad(index->is_btree());
 	ut_a(!dict_index_is_clust(index));
 	ut_ad(!index->table->is_temporary());
 
@@ -3825,7 +3826,7 @@ dump:
 				      		    &offsets, heap, mtr,
 						    &page_cur);
 
-		ut_ad(!cmp_dtuple_rec(entry, rec, offsets));
+		ut_ad(!cmp_dtuple_rec(entry, rec, index, offsets));
 		lock_rec_restore_from_page_infimum(*block, rec,
 						   block->page.id());
 	} else {
diff --git a/storage/innobase/include/data0data.h b/storage/innobase/include/data0data.h
index fc774b6ee60..c6ba41bbfdb 100644
--- a/storage/innobase/include/data0data.h
+++ b/storage/innobase/include/data0data.h
@@ -316,16 +316,6 @@ dtuple_get_n_ext(
 /*=============*/
 	const dtuple_t*	tuple)	/*!< in: tuple */
 	MY_ATTRIBUTE((nonnull));
-/** Compare two data tuples.
-@param[in] tuple1 first data tuple
-@param[in] tuple2 second data tuple
-@return positive, 0, negative if tuple1 is greater, equal, less, than tuple2,
-respectively */
-int
-dtuple_coll_cmp(
-	const dtuple_t*	tuple1,
-	const dtuple_t*	tuple2)
-	MY_ATTRIBUTE((warn_unused_result));
 /** Fold a prefix given as the number of fields of a tuple.
 @param[in]	tuple		index record
 @param[in]	n_fields	number of complete fields to fold
diff --git a/storage/innobase/include/dict0dict.h b/storage/innobase/include/dict0dict.h
index 505fe76b008..7cb254bdc1c 100644
--- a/storage/innobase/include/dict0dict.h
+++ b/storage/innobase/include/dict0dict.h
@@ -1108,16 +1108,16 @@ dict_table_get_nth_col_pos(
 	ulint			n,	/*!< in: column number */
 	ulint*			prefix_col_pos) /*!< out: col num if prefix */
 	MY_ATTRIBUTE((nonnull(1), warn_unused_result));
-/*******************************************************************//**
-Adds a column to index. */
-void
-dict_index_add_col(
-/*===============*/
-	dict_index_t*		index,		/*!< in/out: index */
-	const dict_table_t*	table,		/*!< in: table */
-	dict_col_t*		col,		/*!< in: column */
-	ulint			prefix_len)	/*!< in: column prefix length */
-	MY_ATTRIBUTE((nonnull));
+/** Add a column to an index.
+@param index          index
+@param table          table
+@param col            column
+@param prefix_len     column prefix length
+@param descending     whether to use descending order */
+void dict_index_add_col(dict_index_t *index, const dict_table_t *table,
+                        dict_col_t *col, ulint prefix_len,
+                        bool descending= false)
+  MY_ATTRIBUTE((nonnull));
 
 /*******************************************************************//**
 Copies types of fields contained in index to tuple. */
diff --git a/storage/innobase/include/dict0mem.h b/storage/innobase/include/dict0mem.h
index 744ef5316ef..54e2a99e4bd 100644
--- a/storage/innobase/include/dict0mem.h
+++ b/storage/innobase/include/dict0mem.h
@@ -396,18 +396,7 @@ dict_mem_index_create(
 	ulint		type,		/*!< in: DICT_UNIQUE,
 					DICT_CLUSTERED, ... ORed */
 	ulint		n_fields);	/*!< in: number of fields */
-/**********************************************************************//**
-Adds a field definition to an index. NOTE: does not take a copy
-of the column name if the field is a column. The memory occupied
-by the column name may be released only after publishing the index. */
-void
-dict_mem_index_add_field(
-/*=====================*/
-	dict_index_t*	index,		/*!< in: index */
-	const char*	name,		/*!< in: column name */
-	ulint		prefix_len);	/*!< in: 0 or the column prefix length
-					in a MySQL index like
-					INDEX (textcol(25)) */
+
 /**********************************************************************//**
 Frees an index memory object. */
 void
@@ -886,9 +875,11 @@ struct dict_field_t{
 	unsigned	fixed_len:10;	/*!< 0 or the fixed length of the
 					column if smaller than
 					DICT_ANTELOPE_MAX_INDEX_COL_LEN */
+	/** 1=DESC, 0=ASC */
+	unsigned	descending:1;
 
 	/** Zero-initialize all fields */
-	dict_field_t() : col(NULL), name(NULL), prefix_len(0), fixed_len(0) {}
+	dict_field_t() { memset((void*) this, 0, sizeof *this); }
 
 	/** Check whether two index fields are equivalent.
 	@param[in]	old	the other index field
@@ -1415,6 +1406,21 @@ inline void dict_col_t::detach(const dict_index_t &index)
     reinterpret_cast<dict_v_col_t*>(this)->detach(index);
 }
 
+/** Add a field definition to an index.
+@param index         index
+@param name          pointer to column name
+@param prefix_len    column prefix length, or 0
+@param descending    whether to use descending order */
+inline void dict_mem_index_add_field(dict_index_t *index, const char *name,
+                                     ulint prefix_len, bool descending= false)
+{
+  ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);
+  dict_field_t &field= index->fields[index->n_def++];
+  field.name= name;
+  field.prefix_len= prefix_len & ((1U << 12) - 1);
+  field.descending= descending;
+}
+
 /** The status of online index creation */
 enum online_index_status {
 	/** the index is complete and ready for access */
diff --git a/storage/innobase/include/ibuf0ibuf.ic b/storage/innobase/include/ibuf0ibuf.ic
index 2c2620511c7..2d8265d2206 100644
--- a/storage/innobase/include/ibuf0ibuf.ic
+++ b/storage/innobase/include/ibuf0ibuf.ic
@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1997, 2015, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -130,12 +131,17 @@ ibuf_should_try(
 						a secondary index when we
 						decide */
 {
-	return(innodb_change_buffering
-	       && ibuf.max_size != 0
-	       && !dict_index_is_clust(index)
-	       && !dict_index_is_spatial(index)
-	       && index->table->quiesce == QUIESCE_NONE
-	       && (ignore_sec_unique || !dict_index_is_unique(index)));
+  if (!innodb_change_buffering || !ibuf.max_size || index->is_clust() ||
+      index->is_spatial())
+    return false;
+  if (!ignore_sec_unique && index->is_unique())
+    return false;
+  if (index->table->quiesce != QUIESCE_NONE)
+    return false;
+  for (unsigned i= 0; i < index->n_fields; i++)
+    if (index->fields[i].descending)
+      return false;
+  return true;
 }
 
 /******************************************************************//**
diff --git a/storage/innobase/include/page0cur.ic b/storage/innobase/include/page0cur.ic
index 5ee96dd716d..2b945053f6e 100644
--- a/storage/innobase/include/page0cur.ic
+++ b/storage/innobase/include/page0cur.ic
@@ -272,6 +272,7 @@ page_cur_tuple_insert(
 					      index, rec, *offsets, mtr);
 	}
 
-	ut_ad(!rec || !cmp_dtuple_rec(tuple, rec, *offsets));
+	ut_ad(!rec || !cmp_dtuple_rec(tuple, rec, index, *offsets));
 	return(rec);
 }
+
diff --git a/storage/innobase/include/page0page.h b/storage/innobase/include/page0page.h
index 41e46c2d051..848de6fa4cf 100644
--- a/storage/innobase/include/page0page.h
+++ b/storage/innobase/include/page0page.h
@@ -1161,7 +1161,7 @@ page_find_rec_with_heap_no(
 @return the last record, not delete-marked
 @retval infimum record if all records are delete-marked */
 const rec_t*
-page_find_rec_max_not_deleted(
+page_find_rec_last_not_deleted(
 	const page_t*	page);
 
 #endif /* !UNIV_INNOCHECKSUM */
diff --git a/storage/innobase/include/rem0cmp.h b/storage/innobase/include/rem0cmp.h
index 8d770405fcc..3a30f5a92f3 100644
--- a/storage/innobase/include/rem0cmp.h
+++ b/storage/innobase/include/rem0cmp.h
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1994, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2020, MariaDB Corporation.
+Copyright (c) 2017, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -24,8 +24,7 @@ Comparison services for records
 Created 7/1/1994 Heikki Tuuri
 ************************************************************************/
 
-#ifndef rem0cmp_h
-#define rem0cmp_h
+#pragma once
 
 #include "data0data.h"
 #include "data0type.h"
@@ -43,39 +42,40 @@ cmp_cols_are_equal(
 	ibool			check_charsets);
 					/*!< in: whether to check charsets */
 /** Compare two data fields.
-@param[in] mtype main type
-@param[in] prtype precise type
-@param[in] data1 data field
-@param[in] len1 length of data1 in bytes, or UNIV_SQL_NULL
-@param[in] data2 data field
-@param[in] len2 length of data2 in bytes, or UNIV_SQL_NULL
+@param mtype          main type
+@param prtype         precise type
+@param descending     whether to use descending order
+@param data1          data field
+@param len1           length of data1 in bytes, or UNIV_SQL_NULL
+@param data2          data field
+@param len2           length of data2 in bytes, or UNIV_SQL_NULL
 @return the comparison result of data1 and data2
 @retval 0 if data1 is equal to data2
 @retval negative if data1 is less than data2
 @retval positive if data1 is greater than data2 */
-int
-cmp_data_data(
-	ulint		mtype,
-	ulint		prtype,
-	const byte*	data1,
-	ulint		len1,
-	const byte*	data2,
-	ulint		len2)
-	MY_ATTRIBUTE((warn_unused_result));
+int cmp_data(ulint mtype, ulint prtype, bool descending,
+             const byte *data1, size_t len1, const byte *data2, size_t len2)
+  MY_ATTRIBUTE((warn_unused_result));
 
 /** Compare two data fields.
-@param[in] dfield1 data field; must have type field set
-@param[in] dfield2 data field
+@param dfield1       data field; must have type field set
+@param dfield2       data field
+@param descending    whether to use descending order
 @return the comparison result of dfield1 and dfield2
 @retval 0 if dfield1 is equal to dfield2
 @retval negative if dfield1 is less than dfield2
 @retval positive if dfield1 is greater than dfield2 */
-UNIV_INLINE
-int
-cmp_dfield_dfield(
-/*==============*/
-	const dfield_t*	dfield1,/*!< in: data field; must have type field set */
-	const dfield_t*	dfield2);/*!< in: data field */
+inline int cmp_dfield_dfield(const dfield_t *dfield1, const dfield_t *dfield2,
+                             bool descending= false)
+{
+  ut_ad(dfield_check_typed(dfield1));
+  const dtype_t *type= dfield_get_type(dfield1);
+  return cmp_data(type->mtype, type->prtype, descending,
+                  static_cast<const byte*>(dfield_get_data(dfield1)),
+                  dfield_get_len(dfield1),
+                  static_cast<const byte*>(dfield_get_data(dfield2)),
+                  dfield_get_len(dfield2));
+}
 
 #ifdef UNIV_DEBUG
 /** Compare a GIS data tuple to a physical record.
@@ -103,15 +103,15 @@ inline int cmp_geometry_field(const void *a, const void *b)
   double x2= mach_double_read(mbr2);
   if (x1 > x2)
     return 1;
-  if (x2 > x1)
+  if (x1 < x2)
     return -1;
 
-  double y1= mach_double_read(mbr1 + sizeof(double) * SPDIMS);
-  double y2= mach_double_read(mbr2 + sizeof(double) * SPDIMS);
+  x1= mach_double_read(mbr1 + sizeof(double) * SPDIMS);
+  x2= mach_double_read(mbr2 + sizeof(double) * SPDIMS);
 
-  if (y1 > y2)
+  if (x1 > x2)
     return 1;
-  if (y2 > y1)
+  if (x1 < x2)
     return -1;
 
   /* left lower corner (xmin, ymin) overlaps, now right upper corner */
@@ -120,41 +120,39 @@ inline int cmp_geometry_field(const void *a, const void *b)
 
   if (x1 > x2)
     return 1;
-  if (x2 > x1)
+  if (x1 < x2)
     return -1;
 
-  y1= mach_double_read(mbr1 + sizeof(double) * 2 + sizeof(double));
-  y2= mach_double_read(mbr2 + sizeof(double) * 2 + sizeof(double));
+  x1= mach_double_read(mbr1 + sizeof(double) * 2 + sizeof(double));
+  x2= mach_double_read(mbr2 + sizeof(double) * 2 + sizeof(double));
 
-  if (y1 > y2)
+  if (x1 > x2)
     return 1;
-  if (y2 > y1)
+  if (x1 < x2)
     return -1;
 
   return 0;
 }
 
 /** Compare a data tuple to a physical record.
-@param[in] dtuple data tuple
-@param[in] rec B-tree record
-@param[in] offsets rec_get_offsets(rec)
-@param[in] n_cmp number of fields to compare
-@param[in,out] matched_fields number of completely matched fields
+@param dtuple          data tuple
+@param rec             B-tree index record
+@param index           B-tree index
+@param offsets         rec_get_offsets(rec,index)
+@param n_cmp           number of fields to compare
+@param matched_fields  number of completely matched fields
 @return the comparison result of dtuple and rec
 @retval 0 if dtuple is equal to rec
 @retval negative if dtuple is less than rec
 @retval positive if dtuple is greater than rec */
-int
-cmp_dtuple_rec_with_match_low(
-	const dtuple_t*	dtuple,
-	const rec_t*	rec,
-	const rec_offs*	offsets,
-	ulint		n_cmp,
-	ulint*		matched_fields)
-	MY_ATTRIBUTE((nonnull));
-#define cmp_dtuple_rec_with_match(tuple,rec,offsets,fields)		\
+int cmp_dtuple_rec_with_match_low(const dtuple_t *dtuple, const rec_t *rec,
+                                  const dict_index_t *index,
+                                  const rec_offs *offsets,
+                                  ulint n_cmp, ulint *matched_fields)
+  MY_ATTRIBUTE((nonnull));
+#define cmp_dtuple_rec_with_match(tuple,rec,index,offsets,fields)	\
 	cmp_dtuple_rec_with_match_low(					\
-		tuple,rec,offsets,dtuple_get_n_fields_cmp(tuple),fields)
+		tuple,rec,index,offsets,dtuple_get_n_fields_cmp(tuple),fields)
 /** Compare a data tuple to a physical record.
 @param[in]	dtuple		data tuple
 @param[in]	rec		B-tree or R-tree index record
@@ -178,28 +176,32 @@ cmp_dtuple_rec_with_match_bytes(
 	MY_ATTRIBUTE((warn_unused_result));
 /** Compare a data tuple to a physical record.
 @see cmp_dtuple_rec_with_match
-@param[in] dtuple data tuple
-@param[in] rec B-tree record
-@param[in] offsets rec_get_offsets(rec)
+@param dtuple  data tuple
+@param rec     index record
+@param index   index
+@param offsets rec_get_offsets(rec, index)
 @return the comparison result of dtuple and rec
 @retval 0 if dtuple is equal to rec
 @retval negative if dtuple is less than rec
 @retval positive if dtuple is greater than rec */
-int
-cmp_dtuple_rec(
-	const dtuple_t*	dtuple,
-	const rec_t*	rec,
-	const rec_offs*	offsets);
-/**************************************************************//**
-Checks if a dtuple is a prefix of a record. The last field in dtuple
-is allowed to be a prefix of the corresponding field in the record.
-@return TRUE if prefix */
-ibool
-cmp_dtuple_is_prefix_of_rec(
-/*========================*/
-	const dtuple_t*	dtuple,	/*!< in: data tuple */
-	const rec_t*	rec,	/*!< in: physical record */
-	const rec_offs*	offsets);/*!< in: array returned by rec_get_offsets() */
+inline int cmp_dtuple_rec(const dtuple_t *dtuple, const rec_t *rec,
+                          const dict_index_t *index, const rec_offs *offsets)
+{
+  ulint matched= 0;
+  return cmp_dtuple_rec_with_match(dtuple, rec, index, offsets, &matched);
+}
+
+/** Check if a dtuple is a prefix of a record.
+@param dtuple  data tuple
+@param rec     index record
+@param index   index
+@param offsets rec_get_offsets(rec)
+@return whether dtuple is a prefix of rec */
+bool cmp_dtuple_is_prefix_of_rec(const dtuple_t *dtuple, const rec_t *rec,
+                                 const dict_index_t *index,
+                                 const rec_offs *offsets)
+  MY_ATTRIBUTE((nonnull, warn_unused_result));
+
 /** Compare two physical records that contain the same number of columns,
 none of which are stored externally.
 @retval positive if rec1 (including non-ordering columns) is greater than rec2
@@ -246,18 +248,39 @@ cmp_rec_rec(
 	MY_ATTRIBUTE((nonnull(1,2,3,4,5)));
 
 /** Compare two data fields.
-@param[in] dfield1 data field
-@param[in] dfield2 data field
+@param dfield1        data field
+@param dfield2        data field
 @return the comparison result of dfield1 and dfield2
-@retval 0 if dfield1 is equal to dfield2, or a prefix of dfield1
-@retval negative if dfield1 is less than dfield2
-@retval positive if dfield1 is greater than dfield2 */
-UNIV_INLINE
-int
-cmp_dfield_dfield_like_prefix(
-	const dfield_t*	dfield1,
-	const dfield_t*	dfield2);
+@retval true if dfield1 is equal to dfield2, or a prefix of dfield1
+@retval false otherwise */
+inline bool cmp_dfield_dfield_eq_prefix(const dfield_t *dfield1,
+                                        const dfield_t *dfield2)
+{
+  ut_ad(dfield_check_typed(dfield1));
+  ut_ad(dfield_check_typed(dfield2));
+  const dtype_t *type= dfield_get_type(dfield1);
 
-#include "rem0cmp.ic"
+#ifdef UNIV_DEBUG
+  switch (type->prtype & DATA_MYSQL_TYPE_MASK) {
+  case MYSQL_TYPE_BIT:
+  case MYSQL_TYPE_STRING:
+  case MYSQL_TYPE_VAR_STRING:
+  case MYSQL_TYPE_TINY_BLOB:
+  case MYSQL_TYPE_MEDIUM_BLOB:
+  case MYSQL_TYPE_BLOB:
+  case MYSQL_TYPE_LONG_BLOB:
+  case MYSQL_TYPE_VARCHAR:
+    break;
+  default:
+    ut_error;
+  }
+#endif /* UNIV_DEBUG */
 
-#endif
+  uint cs_num= dtype_get_charset_coll(type->prtype);
+  CHARSET_INFO *cs= get_charset(cs_num, MYF(MY_WME));
+  ut_a(cs);
+  return !cs->strnncoll(static_cast<const uchar*>(dfield_get_data(dfield1)),
+                        dfield_get_len(dfield1),
+                        static_cast<const uchar*>(dfield_get_data(dfield2)),
+                        dfield_get_len(dfield2), 1);
+}
diff --git a/storage/innobase/include/rem0cmp.ic b/storage/innobase/include/rem0cmp.ic
deleted file mode 100644
index 6e21382d187..00000000000
--- a/storage/innobase/include/rem0cmp.ic
+++ /dev/null
@@ -1,107 +0,0 @@
-/*****************************************************************************
-
-Copyright (c) 1994, 2014, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2020, MariaDB Corporation.
-
-This program is free software; you can redistribute it and/or modify it under
-the terms of the GNU General Public License as published by the Free Software
-Foundation; version 2 of the License.
-
-This program is distributed in the hope that it will be useful, but WITHOUT
-ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
-FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License along with
-this program; if not, write to the Free Software Foundation, Inc.,
-51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
-
-*****************************************************************************/
-
-/*******************************************************************//**
-@file include/rem0cmp.ic
-Comparison services for records
-
-Created 7/1/1994 Heikki Tuuri
-************************************************************************/
-
-#include <mysql_com.h>
-#include <my_sys.h>
-
-/** Compare two data fields.
-@param[in] dfield1 data field; must have type field set
-@param[in] dfield2 data field
-@return the comparison result of dfield1 and dfield2
-@retval 0 if dfield1 is equal to dfield2
-@retval negative if dfield1 is less than dfield2
-@retval positive if dfield1 is greater than dfield2 */
-UNIV_INLINE
-int
-cmp_dfield_dfield(
-	const dfield_t*	dfield1,
-	const dfield_t*	dfield2)
-{
-	const dtype_t*	type;
-
-	ut_ad(dfield_check_typed(dfield1));
-
-	type = dfield_get_type(dfield1);
-
-	return(cmp_data_data(type->mtype, type->prtype,
-			     (const byte*) dfield_get_data(dfield1),
-			     dfield_get_len(dfield1),
-			     (const byte*) dfield_get_data(dfield2),
-			     dfield_get_len(dfield2)));
-}
-
-/** Compare two data fields.
-@param[in] dfield1 data field
-@param[in] dfield2 data field
-@return the comparison result of dfield1 and dfield2
-@retval 0 if dfield1 is equal to dfield2, or a prefix of dfield1
-@retval negative if dfield1 is less than dfield2
-@retval positive if dfield1 is greater than dfield2 */
-UNIV_INLINE
-int
-cmp_dfield_dfield_like_prefix(
-	const dfield_t*	dfield1,
-	const dfield_t*	dfield2)
-{
-	const dtype_t*  type;
-
-	ut_ad(dfield_check_typed(dfield1));
-	ut_ad(dfield_check_typed(dfield2));
-
-	type = dfield_get_type(dfield1);
-
-#ifdef UNIV_DEBUG
-	switch (type->prtype & DATA_MYSQL_TYPE_MASK) {
-	case MYSQL_TYPE_BIT:
-	case MYSQL_TYPE_STRING:
-	case MYSQL_TYPE_VAR_STRING:
-	case MYSQL_TYPE_TINY_BLOB:
-	case MYSQL_TYPE_MEDIUM_BLOB:
-	case MYSQL_TYPE_BLOB:
-	case MYSQL_TYPE_LONG_BLOB:
-	case MYSQL_TYPE_VARCHAR:
-		break;
-	default:
-		ut_error;
-	}
-#endif /* UNIV_DEBUG */
-
-	uint cs_num = (uint) dtype_get_charset_coll(type->prtype);
-
-	if (CHARSET_INFO* cs = get_charset(cs_num, MYF(MY_WME))) {
-		return(cs->strnncoll(
-			       static_cast<const uchar*>(
-				       dfield_get_data(dfield1)),
-			       dfield_get_len(dfield1),
-			       static_cast<const uchar*>(
-				       dfield_get_data(dfield2)),
-			       dfield_get_len(dfield2),
-			       1));
-	}
-
-	ib::fatal() << "Unable to find charset-collation " << cs_num;
-	return(0);
-}
diff --git a/storage/innobase/include/row0merge.h b/storage/innobase/include/row0merge.h
index 64d97e6a777..580dbc65c00 100644
--- a/storage/innobase/include/row0merge.h
+++ b/storage/innobase/include/row0merge.h
@@ -109,6 +109,7 @@ struct index_field_t {
 	ulint		prefix_len;	/*!< column prefix length, or 0
 					if indexing the whole column */
 	bool		is_v_col;	/*!< whether this is a virtual column */
+	bool		descending;	/*!< whether to use DESC order */
 };
 
 /** Definition of an index being created */
diff --git a/storage/innobase/page/page0cur.cc b/storage/innobase/page/page0cur.cc
index 41ae2638f47..b43f6e0b900 100644
--- a/storage/innobase/page/page0cur.cc
+++ b/storage/innobase/page/page0cur.cc
@@ -84,7 +84,8 @@ page_cur_try_search_shortcut(
 	low_match = up_match = std::min(*ilow_matched_fields,
 					*iup_matched_fields);
 
-	if (cmp_dtuple_rec_with_match(tuple, rec, offsets, &low_match) < 0) {
+	if (cmp_dtuple_rec_with_match(tuple, rec, index, offsets,
+				      &low_match) < 0) {
 		goto exit_func;
 	}
 
@@ -94,7 +95,7 @@ page_cur_try_search_shortcut(
 					  index->n_core_fields,
 					  dtuple_get_n_fields(tuple), &heap);
 
-		if (cmp_dtuple_rec_with_match(tuple, next_rec, offsets,
+		if (cmp_dtuple_rec_with_match(tuple, next_rec, index, offsets,
 					      &up_match) >= 0) {
 			goto exit_func;
 		}
@@ -398,7 +399,7 @@ page_cur_search_with_match(
 			dtuple_get_n_fields_cmp(tuple), &heap);
 
 		cmp = cmp_dtuple_rec_with_match(
-			tuple, mid_rec, offsets, &cur_matched_fields);
+			tuple, mid_rec, index, offsets, &cur_matched_fields);
 
 		if (cmp > 0) {
 low_slot_match:
@@ -452,7 +453,7 @@ up_slot_match:
 			dtuple_get_n_fields_cmp(tuple), &heap);
 
 		cmp = cmp_dtuple_rec_with_match(
-			tuple, mid_rec, offsets, &cur_matched_fields);
+			tuple, mid_rec, index, offsets, &cur_matched_fields);
 
 		if (cmp > 0) {
 low_rec_match:
diff --git a/storage/innobase/page/page0page.cc b/storage/innobase/page/page0page.cc
index 2f85ef94233..3985f57a586 100644
--- a/storage/innobase/page/page0page.cc
+++ b/storage/innobase/page/page0page.cc
@@ -2466,7 +2466,7 @@ page_find_rec_with_heap_no(
 @return the last record, not delete-marked
 @retval infimum record if all records are delete-marked */
 const rec_t*
-page_find_rec_max_not_deleted(
+page_find_rec_last_not_deleted(
 	const page_t*	page)
 {
 	const rec_t*	rec = page_get_infimum_rec(page);
diff --git a/storage/innobase/pars/pars0opt.cc b/storage/innobase/pars/pars0opt.cc
index e1a913b0179..c9b176150f6 100644
--- a/storage/innobase/pars/pars0opt.cc
+++ b/storage/innobase/pars/pars0opt.cc
@@ -356,6 +356,11 @@ opt_calc_index_goodness(
 	n_fields = dict_index_get_n_unique_in_tree(index);
 
 	for (j = 0; j < n_fields; j++) {
+		if (UNIV_UNLIKELY(index->fields[j].descending)) {
+			/* The internal InnoDB SQL parser does not
+			work with indexes that use DESC order. */
+			return 0;
+		}
 
 		col_no = dict_index_get_nth_col_no(index, j);
 
@@ -575,8 +580,7 @@ opt_search_plan_for_table(
 	best_index = index; /* Eliminate compiler warning */
 	best_goodness = 0;
 
-	/* should be do ... until ? comment by Jani */
-	while (index) {
+	do {
 		goodness = opt_calc_index_goodness(index, sel_node, i,
 						   index_plan, &last_op);
 		if (goodness > best_goodness) {
@@ -591,7 +595,7 @@ opt_search_plan_for_table(
 		}
 
 		dict_table_next_uncorrupted_index(index);
-	}
+	} while (index);
 
 	plan->index = best_index;
 
diff --git a/storage/innobase/rem/rem0cmp.cc b/storage/innobase/rem/rem0cmp.cc
index 70c0255d46a..6b39f6cac56 100644
--- a/storage/innobase/rem/rem0cmp.cc
+++ b/storage/innobase/rem/rem0cmp.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1994, 2019, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2020, MariaDB Corporation.
+Copyright (c) 2020, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -213,37 +213,35 @@ cmp_decimal(const byte*	a, ulint a_length, const byte* b, ulint b_length)
 }
 
 /** Compare two data fields.
-@param[in] mtype main type
-@param[in] prtype precise type
-@param[in] data1 data field
-@param[in] len1 length of data1 in bytes, or UNIV_SQL_NULL
-@param[in] data2 data field
-@param[in] len2 length of data2 in bytes, or UNIV_SQL_NULL
+@param mtype          main type
+@param prtype         precise type
+@param descending     whether to use descending order
+@param data1          data field
+@param len1           length of data1 in bytes, or UNIV_SQL_NULL
+@param data2          data field
+@param len2           length of data2 in bytes, or UNIV_SQL_NULL
 @return the comparison result of data1 and data2
 @retval 0 if data1 is equal to data2
 @retval negative if data1 is less than data2
 @retval positive if data1 is greater than data2 */
-inline
-int
-cmp_data(
-	ulint		mtype,
-	ulint		prtype,
-	const byte*	data1,
-	ulint		len1,
-	const byte*	data2,
-	ulint		len2)
+int cmp_data(ulint mtype, ulint prtype, bool descending,
+             const byte *data1, size_t len1, const byte *data2, size_t len2)
 {
 	ut_ad(len1 != UNIV_SQL_DEFAULT);
 	ut_ad(len2 != UNIV_SQL_DEFAULT);
 
+	int cmp;
+
 	if (len1 == UNIV_SQL_NULL || len2 == UNIV_SQL_NULL) {
 		if (len1 == len2) {
-			return(0);
+			return 0;
+		} else {
+			/* We define the SQL null to be the smallest possible
+			value of a field. */
+			cmp = len1 == UNIV_SQL_NULL ? -1 : 1;
 		}
-
-		/* We define the SQL null to be the smallest possible
-		value of a field. */
-		return(len1 == UNIV_SQL_NULL ? -1 : 1);
+func_exit:
+		return UNIV_UNLIKELY(descending) ? -cmp : cmp;
 	}
 
 	ulint	pad;
@@ -269,7 +267,8 @@ cmp_data(
 		if (prtype & DATA_GIS_MBR) {
 			ut_ad(len1 == DATA_MBR_LEN);
 			ut_ad(len2 == DATA_MBR_LEN);
-			return cmp_geometry_field(data1, data2);
+			cmp = cmp_geometry_field(data1, data2);
+			goto func_exit;
 		}
 		pad = ULINT_UNDEFINED;
 		break;
@@ -286,43 +285,50 @@ cmp_data(
 		/* fall through */
 	case DATA_VARMYSQL:
 	case DATA_MYSQL:
-		return innobase_mysql_cmp(prtype, data1, len1, data2, len2);
+		cmp = innobase_mysql_cmp(prtype, data1, len1, data2, len2);
+		goto func_exit;
 	case DATA_VARCHAR:
 	case DATA_CHAR:
-		return my_charset_latin1.strnncollsp(data1, len1, data2, len2);
+		cmp = my_charset_latin1.strnncollsp(data1, len1, data2, len2);
+		goto func_exit;
 	case DATA_DECIMAL:
-		return cmp_decimal(data1, len1, data2, len2);
+		cmp = cmp_decimal(data1, len1, data2, len2);
+		goto func_exit;
 	case DATA_DOUBLE:
 		{
 			double d_1 = mach_double_read(data1);
 			double d_2 = mach_double_read(data2);
 
 			if (d_1 > d_2) {
-				return 1;
+				cmp = 1;
 			} else if (d_2 > d_1) {
-				return -1;
+				cmp = -1;
+			} else {
+				return 0;
 			}
 		}
-		return 0;
+		goto func_exit;
 
 	case DATA_FLOAT:
 		float f_1 = mach_float_read(data1);
 		float f_2 = mach_float_read(data2);
 
 		if (f_1 > f_2) {
-			return 1;
+			cmp = 1;
 		} else if (f_2 > f_1) {
-			return -1;
+			cmp = -1;
+		} else {
+			return 0;
 		}
 
-		return 0;
+		goto func_exit;
 	}
 
 	ulint len = std::min(len1, len2);
-	int cmp = len ? memcmp(data1, data2, len) : 0;
+	cmp = len ? memcmp(data1, data2, len) : 0;
 
 	if (cmp) {
-		return (cmp);
+		goto func_exit;
 	}
 
 	data1 += len;
@@ -333,7 +339,7 @@ cmp_data(
 	cmp = (int) (len1 - len2);
 
 	if (!cmp || pad == ULINT_UNDEFINED) {
-		return(cmp);
+		goto func_exit;
 	}
 
 	len = 0;
@@ -342,65 +348,46 @@ cmp_data(
 		do {
 			cmp = static_cast<int>(
 				mach_read_from_1(&data1[len++]) - pad);
-		} while (cmp == 0 && len < len1);
+			if (cmp) {
+				goto func_exit;
+			}
+		} while (len < len1);
 	} else {
 		ut_ad(len2 > 0);
 
 		do {
 			cmp = static_cast<int>(
 				pad - mach_read_from_1(&data2[len++]));
-		} while (cmp == 0 && len < len2);
+			if (cmp) {
+				goto func_exit;
+			}
+		} while (len < len2);
 	}
 
-	return(cmp);
-}
-
-/** Compare two data fields.
-@param[in] mtype main type
-@param[in] prtype precise type
-@param[in] data1 data field
-@param[in] len1 length of data1 in bytes, or UNIV_SQL_NULL
-@param[in] data2 data field
-@param[in] len2 length of data2 in bytes, or UNIV_SQL_NULL
-@return the comparison result of data1 and data2
-@retval 0 if data1 is equal to data2
-@retval negative if data1 is less than data2
-@retval positive if data1 is greater than data2 */
-int
-cmp_data_data(
-	ulint		mtype,
-	ulint		prtype,
-	const byte*	data1,
-	ulint		len1,
-	const byte*	data2,
-	ulint		len2)
-{
-	return(cmp_data(mtype, prtype, data1, len1, data2, len2));
+	return 0;
 }
 
 /** Compare a data tuple to a physical record.
-@param[in] dtuple data tuple
-@param[in] rec B-tree record
-@param[in] offsets rec_get_offsets(rec)
-@param[in] n_cmp number of fields to compare
-@param[in,out] matched_fields number of completely matched fields
+@param dtuple          data tuple
+@param rec             B-tree index record
+@param index           B-tree index
+@param offsets         rec_get_offsets(rec,index)
+@param n_cmp           number of fields to compare
+@param matched_fields  number of completely matched fields
 @return the comparison result of dtuple and rec
 @retval 0 if dtuple is equal to rec
 @retval negative if dtuple is less than rec
 @retval positive if dtuple is greater than rec */
-int
-cmp_dtuple_rec_with_match_low(
-	const dtuple_t*	dtuple,
-	const rec_t*	rec,
-	const rec_offs*	offsets,
-	ulint		n_cmp,
-	ulint*		matched_fields)
+int cmp_dtuple_rec_with_match_low(const dtuple_t *dtuple, const rec_t *rec,
+                                  const dict_index_t *index,
+                                  const rec_offs *offsets,
+                                  ulint n_cmp, ulint *matched_fields)
 {
 	ulint		cur_field;	/* current field number */
-	int		ret;		/* return value */
+	int		ret = 0;	/* return value */
 
 	ut_ad(dtuple_check_typed(dtuple));
-	ut_ad(rec_offs_validate(rec, NULL, offsets));
+	ut_ad(rec_offs_validate(rec, index, offsets));
 
 	cur_field = *matched_fields;
 
@@ -414,6 +401,7 @@ cmp_dtuple_rec_with_match_low(
 						     rec_offs_comp(offsets));
 		ulint	tup_info = dtuple_get_info_bits(dtuple);
 
+		/* The "infimum node pointer" is always first. */
 		if (UNIV_UNLIKELY(rec_info & REC_INFO_MIN_REC_FLAG)) {
 			ret = !(tup_info & REC_INFO_MIN_REC_FLAG);
 			goto order_resolved;
@@ -454,7 +442,8 @@ cmp_dtuple_rec_with_match_low(
 
 		ut_ad(!dfield_is_ext(dtuple_field));
 
-		ret = cmp_data(type->mtype, type->prtype,
+		ret = cmp_data(type->mtype, type->prtype, !index->is_ibuf()
+			       && index->fields[cur_field].descending,
 			       dtuple_b_ptr, dtuple_f_len,
 			       rec_b_ptr, rec_f_len);
 		if (ret) {
@@ -462,8 +451,6 @@ cmp_dtuple_rec_with_match_low(
 		}
 	}
 
-	ret = 0;	/* If we ran out of fields, dtuple was equal to rec
-			up to the common fields */
 order_resolved:
 	*matched_fields = cur_field;
 	return(ret);
@@ -534,6 +521,7 @@ cmp_dtuple_rec_with_match_bytes(
 	ut_ad(rec_offs_validate(rec, index, offsets));
 	ut_ad(!(REC_INFO_MIN_REC_FLAG
 		& dtuple_get_info_bits(dtuple)));
+	ut_ad(!index->is_ibuf());
 
 	if (UNIV_UNLIKELY(REC_INFO_MIN_REC_FLAG
 			  & rec_get_info_bits(rec, rec_offs_comp(offsets)))) {
@@ -546,7 +534,7 @@ cmp_dtuple_rec_with_match_bytes(
 	ulint cur_field = *matched_fields;
 	ulint cur_bytes = *matched_bytes;
 	ulint n_cmp = dtuple_get_n_fields_cmp(dtuple);
-	int ret;
+	int ret = 0;
 
 	ut_ad(n_cmp <= dtuple_get_n_fields(dtuple));
 	ut_ad(cur_field <= n_cmp);
@@ -607,7 +595,7 @@ cmp_dtuple_rec_with_match_bytes(
 			}
 			/* fall through */
 		default:
-			ret = cmp_data(type->mtype, type->prtype,
+			ret = cmp_data(type->mtype, type->prtype, false,
 				       dtuple_b_ptr, dtuple_f_len,
 				       rec_b_ptr, rec_f_len);
 
@@ -671,62 +659,29 @@ next_field:
 
 	ut_ad(cur_bytes == 0);
 
-	ret = 0;	/* If we ran out of fields, dtuple was equal to rec
-			up to the common fields */
 order_resolved:
 	*matched_fields = cur_field;
 	*matched_bytes = cur_bytes;
 
-	return(ret);
+	return !ret || UNIV_LIKELY(!index->fields[cur_field].descending)
+		? ret : -ret;
 }
 
-/** Compare a data tuple to a physical record.
-@see cmp_dtuple_rec_with_match
-@param[in] dtuple data tuple
-@param[in] rec B-tree record
-@param[in] offsets rec_get_offsets(rec); may be NULL
-for ROW_FORMAT=REDUNDANT
-@return the comparison result of dtuple and rec
-@retval 0 if dtuple is equal to rec
-@retval negative if dtuple is less than rec
-@retval positive if dtuple is greater than rec */
-int
-cmp_dtuple_rec(
-	const dtuple_t*	dtuple,
-	const rec_t*	rec,
-	const rec_offs*	offsets)
+/** Check if a dtuple is a prefix of a record.
+@param dtuple  data tuple
+@param rec     index record
+@param index   index
+@param offsets rec_get_offsets(rec)
+@return whether dtuple is a prefix of rec */
+bool cmp_dtuple_is_prefix_of_rec(const dtuple_t *dtuple, const rec_t *rec,
+                                 const dict_index_t *index,
+                                 const rec_offs *offsets)
 {
-	ulint	matched_fields	= 0;
-
-	ut_ad(rec_offs_validate(rec, NULL, offsets));
-	return(cmp_dtuple_rec_with_match(dtuple, rec, offsets,
-					 &matched_fields));
-}
-
-/**************************************************************//**
-Checks if a dtuple is a prefix of a record. The last field in dtuple
-is allowed to be a prefix of the corresponding field in the record.
-@return TRUE if prefix */
-ibool
-cmp_dtuple_is_prefix_of_rec(
-/*========================*/
-	const dtuple_t*	dtuple,	/*!< in: data tuple */
-	const rec_t*	rec,	/*!< in: physical record */
-	const rec_offs*	offsets)/*!< in: array returned by rec_get_offsets() */
-{
-	ulint	n_fields;
-	ulint	matched_fields	= 0;
-
-	ut_ad(rec_offs_validate(rec, NULL, offsets));
-	n_fields = dtuple_get_n_fields(dtuple);
-
-	if (n_fields > rec_offs_n_fields(offsets)) {
-		ut_ad(0);
-		return(FALSE);
-	}
-
-	cmp_dtuple_rec_with_match(dtuple, rec, offsets, &matched_fields);
-	return(matched_fields == n_fields);
+  ulint	matched_fields= 0;
+  ulint n_fields= dtuple_get_n_fields(dtuple);
+  ut_ad(n_fields <= rec_offs_n_fields(offsets));
+  cmp_dtuple_rec_with_match(dtuple, rec, index, offsets, &matched_fields);
+  return matched_fields == n_fields;
 }
 
 /*************************************************************//**
@@ -749,7 +704,7 @@ cmp_rec_rec_simple_field(
 	const byte*	rec2_b_ptr;
 	ulint		rec1_f_len;
 	ulint		rec2_f_len;
-	const dict_col_t*	col	= dict_index_get_nth_col(index, n);
+	const dict_field_t* field = dict_index_get_nth_field(index, n);
 
 	ut_ad(!rec_offs_nth_extern(offsets1, n));
 	ut_ad(!rec_offs_nth_extern(offsets2, n));
@@ -757,8 +712,9 @@ cmp_rec_rec_simple_field(
 	rec1_b_ptr = rec_get_nth_field(rec1, offsets1, n, &rec1_f_len);
 	rec2_b_ptr = rec_get_nth_field(rec2, offsets2, n, &rec2_f_len);
 
-	return(cmp_data(col->mtype, col->prtype,
-			rec1_b_ptr, rec1_f_len, rec2_b_ptr, rec2_f_len));
+	return cmp_data(field->col->mtype, field->col->prtype,
+			field->descending,
+			rec1_b_ptr, rec1_f_len, rec2_b_ptr, rec2_f_len);
 }
 
 /** Compare two physical records that contain the same number of columns,
@@ -916,16 +872,19 @@ cmp_rec_rec(
 	for (; cur_field < n_fields; cur_field++) {
 		ulint	mtype;
 		ulint	prtype;
+		bool	descending;
 
 		if (UNIV_UNLIKELY(dict_index_is_ibuf(index))) {
 			/* This is for the insert buffer B-tree. */
 			mtype = DATA_BINARY;
 			prtype = 0;
+			descending = false;
 		} else {
-			const dict_col_t* col = dict_index_get_nth_col(
+			const dict_field_t* field = dict_index_get_nth_field(
 				index, cur_field);
-			mtype = col->mtype;
-			prtype = col->prtype;
+			descending = field->descending;
+			mtype = field->col->mtype;
+			prtype = field->col->prtype;
 
 			if (UNIV_LIKELY(!dict_index_is_spatial(index))) {
 			} else if (cur_field == 0) {
@@ -961,9 +920,8 @@ cmp_rec_rec(
 			goto order_resolved;
 		}
 
-		ret = cmp_data(mtype, prtype,
-			       rec1_b_ptr, rec1_f_len,
-			       rec2_b_ptr, rec2_f_len);
+		ret = cmp_data(mtype, prtype, descending,
+			       rec1_b_ptr, rec1_f_len, rec2_b_ptr, rec2_f_len);
 		if (ret) {
 			goto order_resolved;
 		}
@@ -978,28 +936,3 @@ order_resolved:
 	}
 	return ret;
 }
-
-#ifdef UNIV_COMPILE_TEST_FUNCS
-
-#ifdef HAVE_UT_CHRONO_T
-
-void
-test_cmp_data_data(ulint len)
-{
-	int		i;
-	static byte	zeros[64];
-
-	if (len > sizeof zeros) {
-		len = sizeof zeros;
-	}
-
-	ut_chrono_t	ch(__func__);
-
-	for (i = 1000000; i > 0; i--) {
-		i += cmp_data(DATA_INT, 0, zeros, len, zeros, len);
-	}
-}
-
-#endif /* HAVE_UT_CHRONO_T */
-
-#endif /* UNIV_COMPILE_TEST_FUNCS */
diff --git a/storage/innobase/row/row0ftsort.cc b/storage/innobase/row/row0ftsort.cc
index cc3f19bafc8..5a172fe5da7 100644
--- a/storage/innobase/row/row0ftsort.cc
+++ b/storage/innobase/row/row0ftsort.cc
@@ -96,6 +96,7 @@ row_merge_create_fts_sort_index(
 	field = dict_index_get_nth_field(new_index, 0);
 	field->name = NULL;
 	field->prefix_len = 0;
+	field->descending = false;
 	field->col = static_cast<dict_col_t*>(
 		mem_heap_zalloc(new_index->heap, sizeof(dict_col_t)));
 	field->col->prtype = idx_field->col->prtype | DATA_NOT_NULL;
@@ -112,6 +113,7 @@ row_merge_create_fts_sort_index(
 	field = dict_index_get_nth_field(new_index, 1);
 	field->name = NULL;
 	field->prefix_len = 0;
+	field->descending = false;
 	field->col = static_cast<dict_col_t*>(
 		mem_heap_zalloc(new_index->heap, sizeof(dict_col_t)));
 	field->col->mtype = DATA_INT;
@@ -151,6 +153,7 @@ row_merge_create_fts_sort_index(
 	field = dict_index_get_nth_field(new_index, 2);
 	field->name = NULL;
 	field->prefix_len = 0;
+	field->descending = false;
 	field->col = static_cast<dict_col_t*>(
 		mem_heap_zalloc(new_index->heap, sizeof(dict_col_t)));
 	field->col->mtype = DATA_INT;
diff --git a/storage/innobase/row/row0ins.cc b/storage/innobase/row/row0ins.cc
index b7688c7bfe4..cf108753180 100644
--- a/storage/innobase/row/row0ins.cc
+++ b/storage/innobase/row/row0ins.cc
@@ -1658,7 +1658,7 @@ row_ins_check_foreign_constraint(
 			}
 		}
 
-		cmp = cmp_dtuple_rec(entry, rec, offsets);
+		cmp = cmp_dtuple_rec(entry, rec, check_index, offsets);
 
 		if (cmp == 0) {
 			if (rec_get_deleted_flag(rec,
@@ -1989,7 +1989,7 @@ row_ins_dupl_error_with_rec(
 
 	matched_fields = 0;
 
-	cmp_dtuple_rec_with_match(entry, rec, offsets, &matched_fields);
+	cmp_dtuple_rec_with_match(entry, rec, index, offsets, &matched_fields);
 
 	if (matched_fields < n_unique) {
 
@@ -2122,7 +2122,7 @@ row_ins_scan_sec_index_for_duplicate(
 			continue;
 		}
 
-		cmp = cmp_dtuple_rec(entry, rec, offsets);
+		cmp = cmp_dtuple_rec(entry, rec, index, offsets);
 
 		if (cmp == 0) {
 			if (row_ins_dupl_error_with_rec(rec, entry,
@@ -2159,18 +2159,20 @@ end_scan:
 }
 
 /** Checks for a duplicate when the table is being rebuilt online.
+@param n_uniq   index->db_trx_id()
+@param entry    entry being inserted
+@param rec      clustered index record at insert position
+@param index    clustered index
+@param offsets  rec_get_offsets(rec)
 @retval DB_SUCCESS when no duplicate is detected
 @retval DB_SUCCESS_LOCKED_REC when rec is an exact match of entry or
 a newer version of entry (the entry should not be inserted)
 @retval DB_DUPLICATE_KEY when entry is a duplicate of rec */
 static MY_ATTRIBUTE((nonnull, warn_unused_result))
 dberr_t
-row_ins_duplicate_online(
-/*=====================*/
-	ulint		n_uniq,	/*!< in: offset of DB_TRX_ID */
-	const dtuple_t*	entry,	/*!< in: entry that is being inserted */
-	const rec_t*	rec,	/*!< in: clustered index record */
-	rec_offs*	offsets)/*!< in/out: rec_get_offsets(rec) */
+row_ins_duplicate_online(ulint n_uniq, const dtuple_t *entry,
+                         const rec_t *rec, const dict_index_t *index,
+                         rec_offs *offsets)
 {
 	ulint	fields	= 0;
 
@@ -2178,11 +2180,11 @@ row_ins_duplicate_online(
 	in the new table. */
 	ut_ad(!rec_get_deleted_flag(rec, rec_offs_comp(offsets)));
 	ut_ad(dtuple_get_n_fields_cmp(entry) == n_uniq);
+	ut_ad(n_uniq == index->db_trx_id());
 
-	/* Compare the PRIMARY KEY fields and the
-	DB_TRX_ID, DB_ROLL_PTR. */
-	cmp_dtuple_rec_with_match_low(
-		entry, rec, offsets, n_uniq + 2, &fields);
+	/* Compare the PRIMARY KEY fields and the DB_TRX_ID, DB_ROLL_PTR. */
+	cmp_dtuple_rec_with_match_low(entry, rec, index, offsets, n_uniq + 2,
+				      &fields);
 
 	if (fields < n_uniq) {
 		/* Not a duplicate. */
@@ -2191,7 +2193,7 @@ row_ins_duplicate_online(
 
 	ulint trx_id_len;
 
-	if (fields == n_uniq + 2
+	if (fields == n_uniq
 	    && memcmp(rec_get_nth_field(rec, offsets, n_uniq, &trx_id_len),
 		      reset_trx_id, DATA_TRX_ID_LEN + DATA_ROLL_PTR_LEN)) {
 		ut_ad(trx_id_len == DATA_TRX_ID_LEN);
@@ -2227,7 +2229,8 @@ row_ins_duplicate_error_in_clust_online(
 		*offsets = rec_get_offsets(rec, cursor->index, *offsets,
 					   cursor->index->n_fields,
 					   ULINT_UNDEFINED, heap);
-		err = row_ins_duplicate_online(n_uniq, entry, rec, *offsets);
+		err = row_ins_duplicate_online(n_uniq, entry,
+					       rec, cursor->index, *offsets);
 		if (err != DB_SUCCESS) {
 			return(err);
 		}
@@ -2239,7 +2242,8 @@ row_ins_duplicate_error_in_clust_online(
 		*offsets = rec_get_offsets(rec, cursor->index, *offsets,
 					   cursor->index->n_fields,
 					   ULINT_UNDEFINED, heap);
-		err = row_ins_duplicate_online(n_uniq, entry, rec, *offsets);
+		err = row_ins_duplicate_online(n_uniq, entry,
+					       rec, cursor->index, *offsets);
 	}
 
 	return(err);
diff --git a/storage/innobase/row/row0merge.cc b/storage/innobase/row/row0merge.cc
index 7b1e1b5597f..d4ffe9f2b30 100644
--- a/storage/innobase/row/row0merge.cc
+++ b/storage/innobase/row/row0merge.cc
@@ -928,6 +928,7 @@ static MY_ATTRIBUTE((warn_unused_result))
 int
 row_merge_tuple_cmp(
 /*================*/
+	const dict_index_t*	index,	/*< in: index tree */
 	ulint			n_uniq,	/*!< in: number of unique fields */
 	ulint			n_field,/*!< in: number of fields */
 	const mtuple_t&		a,	/*!< in: first tuple to be compared */
@@ -939,6 +940,7 @@ row_merge_tuple_cmp(
 	const dfield_t*	af	= a.fields;
 	const dfield_t*	bf	= b.fields;
 	ulint		n	= n_uniq;
+	const dict_field_t* f = index->fields;
 
 	ut_ad(n_uniq > 0);
 	ut_ad(n_uniq <= n_field);
@@ -947,7 +949,7 @@ row_merge_tuple_cmp(
 	found or we run out of fields to compare.  If !cmp at the
 	end, the tuples are equal. */
 	do {
-		cmp = cmp_dfield_dfield(af++, bf++);
+		cmp = cmp_dfield_dfield(af++, bf++, (f++)->descending);
 	} while (!cmp && --n);
 
 	if (cmp) {
@@ -972,7 +974,7 @@ no_report:
 	/* The n_uniq fields were equal, but we compare all fields so
 	that we will get the same (internal) order as in the B-tree. */
 	for (n = n_field - n_uniq + 1; --n; ) {
-		cmp = cmp_dfield_dfield(af++, bf++);
+		cmp = cmp_dfield_dfield(af++, bf++, (f++)->descending);
 		if (cmp) {
 			return(cmp);
 		}
@@ -992,7 +994,7 @@ UT_SORT_FUNCTION_BODY().
 @param low lower bound of the sorting area, inclusive
 @param high upper bound of the sorting area, inclusive */
 #define row_merge_tuple_sort_ctx(tuples, aux, low, high)		\
-	row_merge_tuple_sort(n_uniq, n_field, dup, tuples, aux, low, high)
+	row_merge_tuple_sort(index,n_uniq,n_field,dup, tuples, aux, low, high)
 /** Wrapper for row_merge_tuple_cmp() to inject some more context to
 UT_SORT_FUNCTION_BODY().
 @param a first tuple to be compared
@@ -1000,7 +1002,7 @@ UT_SORT_FUNCTION_BODY().
 @return positive, 0, negative, if a is greater, equal, less, than b,
 respectively */
 #define row_merge_tuple_cmp_ctx(a,b)			\
-	row_merge_tuple_cmp(n_uniq, n_field, a, b, dup)
+	row_merge_tuple_cmp(index, n_uniq, n_field, a, b, dup)
 
 /**********************************************************************//**
 Merge sort the tuple buffer in main memory. */
@@ -1008,6 +1010,7 @@ static
 void
 row_merge_tuple_sort(
 /*=================*/
+	const dict_index_t*	index,	/*!< in: index tree */
 	ulint			n_uniq,	/*!< in: number of unique fields */
 	ulint			n_field,/*!< in: number of fields */
 	row_merge_dup_t*	dup,	/*!< in/out: reporter of duplicates
@@ -1035,12 +1038,9 @@ row_merge_buf_sort(
 	row_merge_dup_t*	dup)	/*!< in/out: reporter of duplicates
 					(NULL if non-unique index) */
 {
-	ut_ad(!dict_index_is_spatial(buf->index));
-
-	row_merge_tuple_sort(dict_index_get_n_unique(buf->index),
-			     dict_index_get_n_fields(buf->index),
-			     dup,
-			     buf->tuples, buf->tmp_tuples, 0, buf->n_tuples);
+  ut_ad(!buf->index->is_spatial());
+  row_merge_tuple_sort(buf->index, buf->index->n_uniq, buf->index->n_fields,
+                       dup, buf->tuples, buf->tmp_tuples, 0, buf->n_tuples);
 }
 
 /** Write the blob field data to temporary file and fill the offset,
@@ -1722,11 +1722,10 @@ row_mtuple_cmp(
 	const mtuple_t*		current_mtuple,
 	row_merge_dup_t*	dup)
 {
-	ut_ad(dict_index_is_clust(dup->index));
-	const ulint	n_unique = dict_index_get_n_unique(dup->index);
-
-	return(row_merge_tuple_cmp(
-		       n_unique, n_unique, *current_mtuple, *prev_mtuple, dup));
+  ut_ad(dup->index->is_primary());
+  const ulint n_uniq= dup->index->n_uniq;
+  return row_merge_tuple_cmp(dup->index, n_uniq, n_uniq,
+                             *current_mtuple, *prev_mtuple, dup);
 }
 
 /** Insert cached spatial index rows.
@@ -4528,7 +4527,8 @@ row_merge_create_index(
 			name = dict_table_get_col_name(table, ifield->col_no);
 		}
 
-		dict_mem_index_add_field(index, name, ifield->prefix_len);
+		dict_mem_index_add_field(index, name, ifield->prefix_len,
+					 ifield->descending);
 	}
 
 	if (n_add_vcol) {
diff --git a/storage/innobase/row/row0mysql.cc b/storage/innobase/row/row0mysql.cc
index 757ead4f0e9..7594877d80e 100644
--- a/storage/innobase/row/row0mysql.cc
+++ b/storage/innobase/row/row0mysql.cc
@@ -3086,7 +3086,8 @@ func_exit:
 	if (prev_entry != NULL) {
 		matched_fields = 0;
 
-		cmp = cmp_dtuple_rec_with_match(prev_entry, rec, offsets,
+		cmp = cmp_dtuple_rec_with_match(prev_entry,
+						rec, index, offsets,
 						&matched_fields);
 		contains_null = FALSE;
 
diff --git a/storage/innobase/row/row0purge.cc b/storage/innobase/row/row0purge.cc
index 706a9aecd8f..937a8481b47 100644
--- a/storage/innobase/row/row0purge.cc
+++ b/storage/innobase/row/row0purge.cc
@@ -1306,7 +1306,7 @@ purge_node_t::validate_pcur()
 	part in persistent cursor. Both cases we store n_uniq fields of the
 	cluster index and so it is fine to do the comparison. We note this
 	dependency here as pcur and ref belong to different modules. */
-	int st = cmp_dtuple_rec(ref, pcur.old_rec, offsets);
+	int st = cmp_dtuple_rec(ref, pcur.old_rec, clust_index, offsets);
 
 	if (st != 0) {
 		ib::error() << "Purge node pcur validation failed";
diff --git a/storage/innobase/row/row0sel.cc b/storage/innobase/row/row0sel.cc
index d5fd340ad81..ab4da856d1d 100644
--- a/storage/innobase/row/row0sel.cc
+++ b/storage/innobase/row/row0sel.cc
@@ -149,7 +149,7 @@ row_sel_sec_rec_is_for_blob(
 		return false;
 	}
 
-	return(!cmp_data_data(mtype, prtype, buf, len, sec_field, sec_len));
+	return !cmp_data(mtype, prtype, false, buf, len, sec_field, sec_len);
 }
 
 /** Function to read the secondary spatial index, calculate
@@ -390,9 +390,8 @@ check_for_blob:
 			}
 		}
 
-		if (0 != cmp_data_data(col->mtype, col->prtype,
-				       clust_field, len,
-				       sec_field, sec_len)) {
+		if (cmp_data(col->mtype, col->prtype, false,
+			     clust_field, len, sec_field, sec_len)) {
 			return DB_SUCCESS;
 		}
 	}
@@ -3275,7 +3274,7 @@ class Row_sel_get_clust_rec_for_mysql
       ulint len1, len2;
       const byte *b1= rec_get_nth_field(cached_clust_rec, offsets, n, &len1);
       const byte *b2= rec_get_nth_field(cached_old_vers, vers_offs, n, &len2);
-      ut_ad(!cmp_data_data(col->mtype, col->prtype, b1, len1, b2, len2));
+      ut_ad(!cmp_data(col->mtype, col->prtype, false, b1, len1, b2, len2));
     }
   }
 #endif
@@ -5022,7 +5021,7 @@ wrong_offs:
 
 		/* fputs("Comparing rec and search tuple\n", stderr); */
 
-		if (0 != cmp_dtuple_rec(search_tuple, rec, offsets)) {
+		if (cmp_dtuple_rec(search_tuple, rec, index, offsets)) {
 
 			if (set_also_gap_locks
 			    && !dict_index_is_spatial(index)) {
@@ -5057,7 +5056,8 @@ wrong_offs:
 
 	} else if (match_mode == ROW_SEL_EXACT_PREFIX) {
 
-		if (!cmp_dtuple_is_prefix_of_rec(search_tuple, rec, offsets)) {
+		if (!cmp_dtuple_is_prefix_of_rec(search_tuple, rec,
+						 index, offsets)) {
 
 			if (set_also_gap_locks
 			    && !dict_index_is_spatial(index)) {
@@ -5178,7 +5178,7 @@ wrong_offs:
 		    && direction == 0
 		    && dtuple_get_n_fields_cmp(search_tuple)
 		    == dict_index_get_n_unique(index)
-		    && 0 == cmp_dtuple_rec(search_tuple, rec, offsets)) {
+		    && !cmp_dtuple_rec(search_tuple, rec, index, offsets)) {
 no_gap_lock:
 			lock_type = LOCK_REC_NOT_GAP;
 		}
@@ -6112,24 +6112,36 @@ row_search_get_max_rec(
 {
 	btr_pcur_t	pcur;
 	const rec_t*	rec;
+	const bool	desc	= index->fields[0].descending;
 	/* Open at the high/right end (false), and init cursor */
 	btr_pcur_open_at_index_side(
-		false, index, BTR_SEARCH_LEAF, &pcur, true, 0, mtr);
+		desc, index, BTR_SEARCH_LEAF, &pcur, true, 0, mtr);
 
-	do {
-		const page_t*	page;
-
-		page = btr_pcur_get_page(&pcur);
-		rec = page_find_rec_max_not_deleted(page);
-
-		if (page_rec_is_user_rec(rec)) {
-			break;
-		} else {
-			rec = NULL;
+	if (desc) {
+		const bool comp = index->table->not_redundant();
+		while (btr_pcur_move_to_next_user_rec(&pcur, mtr)) {
+			rec = btr_pcur_get_rec(&pcur);
+			if (rec_is_metadata(rec, *index)) {
+				continue;
+			}
+			if (!rec_get_deleted_flag(rec, comp)) {
+				goto found;
+			}
 		}
-		btr_pcur_move_before_first_on_page(&pcur);
-	} while (btr_pcur_move_to_prev(&pcur, mtr));
+	} else {
+		do {
+			rec = page_find_rec_last_not_deleted(
+				btr_pcur_get_page(&pcur));
+			if (page_rec_is_user_rec(rec)) {
+				goto found;
+			}
+			btr_pcur_move_before_first_on_page(&pcur);
+		} while (btr_pcur_move_to_prev(&pcur, mtr));
+	}
+
+	rec = nullptr;
 
+found:
 	btr_pcur_close(&pcur);
 
 	ut_ad(!rec
diff --git a/storage/innobase/row/row0vers.cc b/storage/innobase/row/row0vers.cc
index 695c6dba472..4a07072fdd6 100644
--- a/storage/innobase/row/row0vers.cc
+++ b/storage/innobase/row/row0vers.cc
@@ -325,7 +325,7 @@ not_locked:
 
 		/* We check if entry and rec are identified in the alphabetical
 		ordering */
-		if (0 == cmp_dtuple_rec(entry, rec, offsets)) {
+		if (0 == cmp_dtuple_rec(entry, rec, index, offsets)) {
 			/* The delete marks of rec and prev_version should be
 			equal for rec to be in the state required by
 			prev_version */
@@ -343,7 +343,7 @@ not_locked:
 			dtuple_set_types_binary(
 				entry, dtuple_get_n_fields(entry));
 
-			if (0 != cmp_dtuple_rec(entry, rec, offsets)) {
+			if (cmp_dtuple_rec(entry, rec, index, offsets)) {
 
 				break;
 			}
@@ -730,7 +730,7 @@ row_vers_vc_matches_cluster(
 
 				/* The index field mismatch */
 				if (v_heap
-				    || cmp_dfield_dfield(field2, field1) != 0) {
+				    || cmp_dfield_dfield(field2, field1)) {
 					if (v_heap) {
 						dtuple_dup_v_fld(*vrow, v_heap);
 					}
@@ -833,6 +833,21 @@ row_vers_build_cur_vrow(
 	return(cur_vrow);
 }
 
+/** @return whether two data tuples are equal */
+static bool dtuple_coll_eq(const dtuple_t &tuple1, const dtuple_t &tuple2)
+{
+  ut_ad(tuple1.magic_n == DATA_TUPLE_MAGIC_N);
+  ut_ad(tuple2.magic_n == DATA_TUPLE_MAGIC_N);
+  ut_ad(dtuple_check_typed(&tuple1));
+  ut_ad(dtuple_check_typed(&tuple2));
+  ut_ad(tuple1.n_fields == tuple2.n_fields);
+
+  for (ulint i= 0; i < tuple1.n_fields; i++)
+    if (cmp_dfield_dfield(&tuple1.fields[i], &tuple2.fields[i]))
+      return false;
+  return true;
+}
+
 /** Finds out if a version of the record, where the version >= the current
 purge view, should have ientry as its secondary index entry. We check
 if there is any not delete marked version of the record where the trx
@@ -933,7 +948,7 @@ row_vers_old_has_index_entry(
 
 				entry = row_build_index_entry(
 					row, ext, index, heap);
-				if (entry && !dtuple_coll_cmp(ientry, entry)) {
+				if (entry && dtuple_coll_eq(*ientry, *entry)) {
 					goto unsafe_to_purge;
 				}
 			} else {
@@ -988,7 +1003,7 @@ row_vers_old_has_index_entry(
 			the clustered index record has already been updated to
 			a different binary value in a char field, but the
 			collation identifies the old and new value anyway! */
-			if (entry && !dtuple_coll_cmp(ientry, entry)) {
+			if (entry && dtuple_coll_eq(*ientry, *entry)) {
 unsafe_to_purge:
 				mem_heap_free(heap);
 
@@ -1086,7 +1101,7 @@ unsafe_to_purge:
 			a char field, but the collation identifies the old
 			and new value anyway! */
 
-			if (entry && !dtuple_coll_cmp(ientry, entry)) {
+			if (entry && dtuple_coll_eq(*ientry, *entry)) {
 				goto unsafe_to_purge;
 			}
 		}