Really Fixed?

[marc steikert]

I thought about Fixed Tables that "Each row is stored using a fixed number of bytes" but ...


mysql> drop table if exists t;
Query OK, 0 rows affected (0.01 sec)

mysql> create table t (id int) engine = myisam partition by hash(id) partitions 2;
Query OK, 0 rows affected (0.04 sec)

mysql> insert into `t` values (1),(2),(3),(4),(5),(6),(7),(8),(9);
Query OK, 9 rows affected (0.00 sec)
Datensätze: 9 Duplikate: 0 Warnungen: 0

mysql> show table status like 't'\G
*************************** 1. row ***************************
Name: t
Engine: MyISAM
Version: 10
Row_format: Fixed
Rows: 9
Avg_row_length: 7
Data_length: 63
Max_data_length: 0
Index_length: 2048
Data_free: 0
Auto_increment: NULL
Create_time: 2006-04-30 00:13:23
Update_time: 2006-04-30 00:13:23
Check_time: NULL
Collation: utf8_general_ci
Checksum: NULL
Create_options: partitioned
Comment:
1 row in set (0.00 sec)

mysql> delete from t where id > 5;
Query OK, 4 rows affected (0.00 sec)

mysql> show table status like 't'\G
*************************** 1. row ***************************
Name: t
Engine: MyISAM
Version: 10
Row_format: Fixed
Rows: 5
Avg_row_length: 12
Data_length: 63
Max_data_length: 0
Index_length: 2048
Data_free: 0
Auto_increment: NULL
Create_time: 2006-04-30 00:13:23
Update_time: 2006-04-30 00:13:23
Check_time: NULL
Collation: utf8_general_ci
Checksum: NULL
Create_options: partitioned
Comment:
1 row in set (0.00 sec)

mysql> alter table t optimize partition p0,p1;
Query OK, 0 rows affected (0.01 sec)
Datensätze: 0 Duplikate: 0 Warnungen: 0

mysql> show table status like 't'\G
*************************** 1. row ***************************
Name: t
Engine: MyISAM
Version: 10
Row_format: Fixed
Rows: 5
Avg_row_length: 7
Data_length: 35
Max_data_length: 0
Index_length: 2048
Data_free: 0
Auto_increment: NULL
Create_time: 2006-04-30 00:13:23
Update_time: 2006-04-30 00:13:23
Check_time: 2006-04-30 00:13:23
Collation: utf8_general_ci
Checksum: NULL
Create_options: partitioned
Comment:
1 row in set (0.00 sec)


... it look's like dynamic
... and thus is Data_free = 0 ???