>>>>> "Mike" == Mike Gohlke <mike@stripped> writes:
Mike> Monty, Sisna and others,
Mike> After having to revert back to mysql 3.22.25 because of major corruption
Mike> problems, etc with 3.23.02 I found a major bug in the alter table code of
Mike> 3.23.02. Namely, when doing a "Alter table tbl type=isam" all blob types
Mike> in tbl become NULL. However, the file size remains the same.
Mike> Mike...
Hi!
Things are not that bad as it sounds:
mysql> create table t1 (a int, b blob);
Query OK, 0 rows affected (0.15 sec)
mysql> insert into t1 values (1,"one"),(2,"two");
Query OK, 2 rows affected (0.15 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> select * from t1;
+------+------+
| a | b |
+------+------+
| 1 | one |
| 2 | two |
+------+------+
2 rows in set (0.02 sec)
mysql> ALTER TABLE t1 type=isam;
Query OK, 2 rows affected (0.02 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> select * from t1;
+------+------+
| a | b |
+------+------+
| 1 | one |
| 2 | two |
+------+------+
2 rows in set (0.01 sec)
The problem is that if we restart mysqld 3.22:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2 to server version: 3.22.26-debug
Type 'help' for help.
mysql> select * from t1;
+------+------+
| a | b |
+------+------+
| 1 | NULL |
| 2 | NULL |
+------+------+
2 rows in set (0.00 sec)
All your data in your table is still there!
You can access these by applying the following patch to your 3.22
version:
*** /my/monty/master/mysql-3.22.24/sql/dfunc.cc Sat Jul 3 20:29:52 1999
--- ./dfunc.cc Sun Aug 29 05:02:17 1999
***************
*** 267,273 ****
if (null_field_first)
{
outparam->null_flags=null_pos= (uchar*) record+1;
! null_bit= (outparam->db_create_options & HA_PACK_RECORD) ? 1 : 2;
}
else
{
--- 267,273 ----
if (null_field_first)
{
outparam->null_flags=null_pos= (uchar*) record+1;
! null_bit= (outparam->db_create_options & HA_OPTION_PACK_RECORD) ? 1 : 2;
}
else
{
Regards,
Monty
