[#MDEV-23530] ERROR 1071: Specified key was too long; max key length is 1000/2000 bytes on CREATE TABLE ... UNIQUE KEY ... USING HASH

# First 3 succeed, last one fails with 'ERROR 1071 (42000): Specified key was too long; max key length is 2000 bytes'

CREATE TABLE t1(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=InnoDB;

CREATE TABLE t2(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=MyISAM;

CREATE TABLE t3(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=MEMORY;

CREATE TABLE t4(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=Aria;

Leads to:

10.5.6 1c587481966abc7a9ad5309d0a91ca920f7a5657 (Optimized)
10.5.6>CREATE TABLE t1(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=InnoDB;
Query OK, 0 rows affected (0.013 sec)
10.5.6>CREATE TABLE t2(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=MyISAM;
Query OK, 0 rows affected (0.002 sec)
10.5.6>CREATE TABLE t3(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=MEMORY;
Query OK, 0 rows affected (0.002 sec)
10.5.6>CREATE TABLE t4(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=Aria;
ERROR 1071 (42000): Specified key was too long; max key length is 2000 bytes

10.4.15 eae968f62d285de97ed607c87bc131cd863d5d03 (Optimized)
10.4.15>CREATE TABLE t4(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=Aria;
ERROR 1071 (42000): Specified key was too long; max key length is 1000 bytes

Also note the 1000 vs 2000 inconsistency between 10.4 and 10.5

It is a regression:

10.3.25 bafc5c1321a7dff5f2da292111bf98fed9d1658d (Optimized)
10.3.25>CREATE TABLE t4(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=Aria;
Query OK, 0 rows affected (0.012 sec)

10.2.34 (Optimized)
10.2.34>CREATE TABLE t4(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=Aria;
Query OK, 0 rows affected (0.01 sec)

10.1.47 (Optimized)
10.1.47>CREATE TABLE t4(c CHAR(1), UNIQUE KEY i(c) USING HASH) ENGINE=Aria;
Query OK, 0 rows affected (0.01 sec)

[MDEV-23530] ERROR 1071: Specified key was too long; max key length is 1000/2000 bytes on CREATE TABLE ... UNIQUE KEY ... USING HASH Created: 2020-08-21 Updated: 2023-03-03
Status:	Open
Project:	MariaDB Server
Component/s:	Storage Engine - Aria
Affects Version/s:	10.4, 10.5, 10.6, 10.7, 10.8, 10.9
Fix Version/s:	10.4, 10.5, 10.6