Problems with the QueryCache

[Jan Lüdtke]

Hiho,

I have a problem with the Query-Caching of 5.0.37 MySQL Community Server
I'll try to explain my Problem with a few samples:

I've got a simple table:

mysql> show full columns from werte;
+-------------+--------------+-----------------+------+-----+---------+-------+----------------------+---------+
| Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment |
+-------------+--------------+-----------------+------+-----+---------+-------+----------------------+---------+
| eigenschaft | varchar(255) | utf8_unicode_ci | NO | PRI | | | select,insert,update | |
| wert | varchar(255) | utf8_unicode_ci | NO | | | | select,insert,update | |
+-------------+--------------+-----------------+------+-----+---------+-------+----------------------+---------+
2 rows in set (0.02 sec)

it has some tupels:

mysql> select * from werte;
+-------------+------+
| eigenschaft | wert |
+-------------+------+
| a | 1 |
| b | 2 |
| suppenhuhn | blub |
+-------------+------+
3 rows in set (0.02 sec)

I now wanna insert/update a tuple:

mysql> insert into werte set eigenschaft = 'suppenhuhn' , wert = "hugo" on duplicate key update eigenschaft = "suppenhuhn" , wert ="hugo";
Query OK, 0 rows affected (0.38 sec)

Ok, let look at the table again:

mysql> select * from werte;
+-------------+------+
| eigenschaft | wert |
+-------------+------+
| a | 1 |
| b | 2 |
| suppenhuhn | blub |
+-------------+------+
3 rows in set (0.02 sec)

Huh?? No update??
Lets try:

mysql> select * from werte where wert ='blub';
Empty set (0.02 sec)

Whats that?? Lets check for the new value:

mysql> select * from werte where wert ="hugo";
+-------------+------+
| eigenschaft | wert |
+-------------+------+
| suppenhuhn | hugo |
+-------------+------+
1 row in set (0.02 sec)

And again:
mysql> select * from werte;
+-------------+------+
| eigenschaft | wert |
+-------------+------+
| a | 1 |
| b | 2 |
| suppenhuhn | blub |
+-------------+------+
3 rows in set (0.02 sec)


I guess you see my Problem :)
I allready found out that the Query-cache is responsible for this.
If I modify the select query, without changing the statement, by adding some whitespaces, it will give me the right values.. at the first time, of cause

So whats wrong with the Server..??