DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (d1 DECIMAL(10,2) <CUSTOM_COL_OPTIONS>,
d2 DECIMAL(60,10) <CUSTOM_COL_OPTIONS>,
n1 NUMERIC <CUSTOM_COL_OPTIONS>,
n2 NUMERIC(65,4) <CUSTOM_COL_OPTIONS>,
<CUSTOM_INDEX> d1 (d1)
) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
SHOW INDEX 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	#	1	d1	#	#	NULL	NULL	#	#		
INSERT INTO t1 (d1,d2,n1,n2) VALUES 
(10.22,60.12345,123456,14.3456),
(10.0,60.12345,123456,14),
(11.14,15,123456,13),
(100,100,1,2),
(0,0,0,0),
(4540424564.23,3343303441.0,12,13),
(15,17,23,100000);
Warnings:
Warning	1264	Out of range value for column 'd1' at row 6
SELECT d1 FROM t1 ORDER BY d1 DESC;
d1
99999999.99
100.00
15.00
11.14
10.22
10.00
0.00
DROP TABLE t1;
CREATE TABLE t1 (d1 DECIMAL(10,2) <CUSTOM_COL_OPTIONS> PRIMARY KEY,
d2 DECIMAL(60,10) <CUSTOM_COL_OPTIONS>,
n1 NUMERIC <CUSTOM_COL_OPTIONS>,
n2 NUMERIC(65,4) <CUSTOM_COL_OPTIONS>
) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
SHOW INDEX 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	PRIMARY	1	d1	#	#	NULL	NULL	#	#		
INSERT INTO t1 (d1,d2,n1,n2) VALUES 
(10.22,60.12345,123456,14.3456),
(10.0,60.12345,123456,14),
(11.14,15,123456,13),
(100,100,1,2),
(0,0,0,0),
(4540424564.23,3343303441.0,12,13),
(15,17,23,100000);
Warnings:
Warning	1264	Out of range value for column 'd1' at row 6
EXPLAIN SELECT d1 FROM t1 ORDER BY d1 DESC;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
#	#	#	#	#	PRIMARY	#	#	#	#
SELECT d1 FROM t1 ORDER BY d1 DESC;
d1
99999999.99
100.00
15.00
11.14
10.22
10.00
0.00
EXPLAIN SELECT d1 FROM t1 IGNORE INDEX FOR ORDER BY (PRIMARY) ORDER BY d1 DESC;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
#	#	#	#	#	PRIMARY	#	#	#	#
SELECT d1 FROM t1 IGNORE INDEX FOR ORDER BY (PRIMARY) ORDER BY d1 DESC;
d1
99999999.99
100.00
15.00
11.14
10.22
10.00
0.00
DROP TABLE t1;
CREATE TABLE t1 (d1 DECIMAL(10,2) <CUSTOM_COL_OPTIONS>,
d2 DECIMAL(60,10) <CUSTOM_COL_OPTIONS>,
n1 NUMERIC <CUSTOM_COL_OPTIONS>,
n2 NUMERIC(65,4) <CUSTOM_COL_OPTIONS>,
UNIQUE INDEX n1_n2 (n1,n2)
) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
SHOW INDEX 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	n1_n2	1	n1	#	#	NULL	NULL	#	#		
t1	0	n1_n2	2	n2	#	#	NULL	NULL	#	#		
INSERT INTO t1 (d1,d2,n1,n2) VALUES
(10.22,60.12345,123456,14.3456),
(10.0,60.12345,123456,14),
(11.14,15,123456,13),
(100,100,1,2),
(0,0,0,0),
(4540424564.23,3343303441.0,12,13),
(15,17,23,100000);
Warnings:
Warning	1264	Out of range value for column 'd1' at row 6
EXPLAIN SELECT DISTINCT n1+n2 FROM t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
#	#	#	#	#	n1_n2	#	#	#	#
SELECT DISTINCT n1+n2 FROM t1;
n1+n2
0.0000
100023.0000
123469.0000
123470.0000
123470.3456
25.0000
3.0000
DROP TABLE t1;
CREATE TABLE t1 (d1 DECIMAL(10,2) <CUSTOM_COL_OPTIONS>,
d2 DECIMAL(60,10) <CUSTOM_COL_OPTIONS>,
n1 NUMERIC <CUSTOM_COL_OPTIONS>,
n2 NUMERIC(65,4) <CUSTOM_COL_OPTIONS>,
INDEX (d2)
) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
SHOW INDEX 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	d2	1	d2	#	#	NULL	NULL	#	#		
INSERT INTO t1 (d1,d2,n1,n2) VALUES
(10.22,60.12345,123456,14.3456),
(10.0,60.12345,123456,14),
(11.14,15,123456,13),
(100,100,1,2),
(0,0,0,0),
(4540424564.23,3343303441.0,12,13),
(15,17,23,100000);
Warnings:
Warning	1264	Out of range value for column 'd1' at row 6
EXPLAIN SELECT d2, COUNT(*) FROM t1 GROUP BY d2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
#	#	#	#	#	d2	#	#	#	#
SELECT d2, COUNT(*) FROM t1 GROUP BY d2;
d2	COUNT(*)
0.0000000000	1
100.0000000000	1
15.0000000000	1
17.0000000000	1
3343303441.0000000000	1
60.1234500000	2
EXPLAIN SELECT d2, COUNT(*) FROM t1 IGNORE INDEX FOR GROUP BY (d2) GROUP BY d2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
#	#	#	#	#	d2	#	#	#	#
SELECT d2, COUNT(*) FROM t1 IGNORE INDEX FOR GROUP BY (d2) GROUP BY d2;
d2	COUNT(*)
0.0000000000	1
100.0000000000	1
15.0000000000	1
17.0000000000	1
3343303441.0000000000	1
60.1234500000	2
DROP TABLE t1;