linux - debian 10

There has been no change. transaction-isolation has always been a server option (command-line or config file option), while tx_isolation – a system variable.

Here are the oldest versions of MariaDB and MySQL that I have handy:

MariaDB [test]> show variables like '%isolation%';

+---------------+-----------------+

| Variable_name | Value           |

+---------------+-----------------+

| tx_isolation  | REPEATABLE-READ |

+---------------+-----------------+

1 row in set (0.001 sec)

MariaDB [test]> select @@version;

+----------------+

| @@version      |

+----------------+

| 5.5.23-MariaDB |

+----------------+

1 row in set (0.000 sec)

MySQL [test]> show variables like '%isolation%';

+---------------+-----------------+

| Variable_name | Value           |

+---------------+-----------------+

| tx_isolation  | REPEATABLE-READ |

+---------------+-----------------+

1 row in set (0.001 sec)

MySQL [test]> select @@version, @@version_comment;

+-----------+------------------------------+

| @@version | @@version_comment            |

+-----------+------------------------------+

| 5.5.62    | MySQL Community Server (GPL) |

+-----------+------------------------------+

1 row in set (0.000 sec)

Hello,

Yes the "transaction-isolation" value is server side, but I mean the system variable 'transaction_isolation' is missing in mariadb 10.5. The most applications doesnt understand the new variable 'tx_isolation'.

Regards
Lukas

Again, there has been no change. As you can see in the output above, there was never "transaction_isolation" system variable, not even in 5.5, neither in MySQL 5.5 nor in MariaDB 5.5; and there has always been tx_isolation variable, it is by no means "new".

Is there a way to add an alias to the variable 'tx_isolation'? The most applications doesnt understand the old 'tx_isolation'.

and see issue: https://jira.mariadb.org/browse/MDEV-21921

Regards
Lukas

Yes, as you can see, there is already a change request for this. But not because "most applications don't understand tx_isolation". Most applications do understand it, because it's an old variable which has been there for a very long time. The request has been made to make the option/variable naming more consistent and transparent for a human being.

I guess you developed your application based on MySQL 5.7 which started deprecating the tx_isolation variable and renaming it into transaction_isolation, and you didn't implement processing of the old name, that's the only reason I could think of why you'd be having this problem. That's certainly not the case for most applications.

It look like, you didnt understand the problem with it. I'm not developing any applications with that problem. The best way to solve the issue is, to add an alias too the variable 'tx_isolation'.
With the mariadb version 10.3.22 it work, but not in the newest versions.

Regards
Lukas

Please execute

select @@transaction_isolation;

select @@version;

via the command-line client on MariaDB 10.3.22 server and paste the unmodified output to demonstrate how it works.

I dont have the old mariadb server anymore.

You can download any version of your choosing from here: https://downloads.mariadb.org/mariadb/+releases/

Oke, I checked it and I found out, the variable also doesnt exists on 10.3.22. Very strange, but why does it work on this version and not on the newest versions?

Is there any special setting for it?

Regards
Lukas