CREATE TABLE t1 (a <INT_COLUMN>,
b <CHAR_COLUMN>,
<CUSTOM_INDEX> (a)
) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
SHOW KEYS IN t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
t1	1	a	1	a	#	#	NULL	NULL	#	BTREE		
DROP TABLE t1;
CREATE TABLE t1 (a <INT_COLUMN>,
b <CHAR_COLUMN>,
<CUSTOM_INDEX> a_b (a,b) COMMENT 'a_b index'
 ) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
SHOW KEYS IN t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
t1	1	a_b	1	a	#	#	NULL	NULL	#	BTREE		a_b index
t1	1	a_b	2	b	#	#	NULL	NULL	#	BTREE		a_b index
DROP TABLE t1;
CREATE TABLE t1 (a <INT_COLUMN>,
b <CHAR_COLUMN>,
<CUSTOM_INDEX> (a),
<CUSTOM_INDEX> (b)
) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
SHOW KEYS IN t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
t1	1	a	1	a	#	#	NULL	NULL	#	BTREE		
t1	1	b	1	b	#	#	NULL	NULL	#	BTREE		
DROP TABLE t1;
CREATE TABLE t1 (a <INT_COLUMN>,
b <CHAR_COLUMN>,
UNIQUE INDEX (a)
) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
SHOW KEYS IN t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
t1	0	a	1	a	#	#	NULL	NULL	#	BTREE		
INSERT INTO t1 (a,b) VALUES (1,'a'),(2,'b');
INSERT INTO t1 (a,b) VALUES (1,'c');
ERROR 23000: Duplicate entry '1' for key 'a'
# Statement ended with one of expected results (ER_DUP_ENTRY,ER_DUP_KEY). 
# If you got a difference in error message, just add it to rdiff file
DROP TABLE t1;
CREATE TABLE t1 (a <INT_COLUMN>, b <CHAR_COLUMN>) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
INSERT INTO t1 (a,b) VALUES (100,'z');
ALTER TABLE t1 ADD <CUSTOM_INDEX> (a) COMMENT 'simple index on a';
SHOW INDEX FROM t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
t1	1	a	1	a	#	#	NULL	NULL	#	BTREE		simple index on a
ALTER TABLE t1 DROP KEY a;
DROP TABLE t1;
CREATE TABLE t1 (a <INT_COLUMN>,
b <CHAR_COLUMN>,
UNIQUE INDEX (a)
) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
SHOW KEYS IN t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment	Index_comment
t1	0	a	1	a	#	#	NULL	NULL	#	BTREE		
INSERT INTO t1 (a,b) VALUES (1,'a'),(2,'b');
INSERT INTO t1 (a,b) VALUES (1,'c');
ERROR 23000: Duplicate entry '1' for key 'a'
# Statement ended with one of expected results (ER_DUP_ENTRY,ER_DUP_KEY). 
# If you got a difference in error message, just add it to rdiff file
ALTER TABLE t1 DROP INDEX a;
INSERT INTO t1 (a,b) VALUES (1,'c');
ALTER TABLE t1 ADD UNIQUE INDEX a(a) ;
ERROR 23000: Duplicate entry '1' for key 'a'
# Statement ended with one of expected results (ER_DUP_ENTRY,ER_DUP_KEY). 
# If you got a difference in error message, just add it to rdiff file
DROP TABLE t1;