Re: Really Fixed?

[marc steikert]

Hi Mikael,
the Data_free length ist now correct but the Avg_row_length length is'nt.
In Fixed Tables "Each row is stored using a fixed number of bytes" so must Avg_row_length length using 7 bytes per record (in this Example) or think i wrongly (see after delete)?

mysql> select version();
+-------------+
| version() |
+-------------+
| 5.1.11-beta |
+-------------+
1 row in set (0.00 sec)


mysql> drop table if exists t;
Query OK, 0 rows affected (0.00 sec)

mysql> create table t (id int) engine = myisam partition by hash(id) partitions 2;
Query OK, 0 rows affected (0.00 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: 2006-06-09 16:01:49
Update_time: 2006-06-09 16:01:49
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: 28
Auto_increment: NULL
Create_time: 2006-06-09 16:01:49
Update_time: 2006-06-09 16:01:49
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 (0.00 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: 2006-06-09 16:01:49
Update_time: 2006-06-09 16:01:50
Check_time: 2006-06-09 16:01:50
Collation: utf8_general_ci
Checksum: NULL
Create_options: partitioned
Comment:
1 row in set (0.00 sec)


Best Regards Marc