So the problem query is:
```
select count(recipient) from transactions;
```
?

Can you share the output of:
```
SHOW CREATE TABLE transactions;
```
?

It could be the difference between cold caches and hot caches.
Are the tables InnoDB on both versions? Is innodb_buffer_pool_size the same?

Can you run this twice, and report back the second timing?
```
select SQL_NO_CACHE count(recipient) from transactions;
```




On Mon, 24 Mar 2025 at 18:15, Olivier Miquel <[email protected]> wrote:
>
> Hello,
>
> Thanks for your answer.
>
> In this case the slowdown is occuring with simple select queries on a
> table. No join.
>
> How could this be possible between two versions?
>
> O.
>
>
> Le 24/03/2025 à 16:34, Gordan Bobic a écrit :
> > If you are seeing a difference of 3.5 orders of magnitude, that is
> > almost certainly not something you can tune out with configuration
> > options.
> > You'll need to look at the queries and work out which ones are now
> > running with a sub-optimal execution profile. Once you identify them,
> > you'll have to apply index or join order hints to get them back onto a
> > sensible execution plan.
> >
> > On Mon, 24 Mar 2025 at 17:16, Olivier Miquel via discuss
> > <[email protected]> wrote:
> >> Hello,
> >>
> >> I am experiencing major performance problems when upgrading our version of 
> >> mariadb from debian 10 ( mariadb 10.3 ) to debian 12 ( mariadb 10.5 ).
> >> It's especially when accessing a table with about 2 million records that 
> >> requests are much slower ( 4.7 seconds vs 0.001 s ) to the point of making 
> >> our application unusable.
> >> I've observed this between two versions of mariadb, each with default 
> >> settings in Debian.
> >>
> >> I've tried changing the settings several times, but nothing seems to help.
> >>
> >> Do you have any idea why this big difference in performance and how to fix 
> >> it?
> >>
> >> Thanks for your help,
> >>
> >> ______________
> >>
> >>
> >> _______
> >>
> >> MariaDB [cfms_accounting]> DESCRIBE transactions;
> >> +---------------------+------------------+------+-----+---------+----------------+
> >> | Field               | Type             | Null | Key | Default | Extra    
> >>       |
> >> +---------------------+------------------+------+-----+---------+----------------+
> >> | id                  | int(10) unsigned | NO   | PRI | NULL    | 
> >> auto_increment |
> >> | reference           | varchar(255)     | NO   | UNI | NULL    |          
> >>       |
> >> | recipient           | varchar(255)     | YES  |     | NULL    |          
> >>       |
> >> | sender              | varchar(255)     | YES  |     | NULL    |          
> >>       |
> >> | sender_reference    | varchar(255)     | YES  |     | NULL    |          
> >>       |
> >> | amount              | double(15,8)     | NO   |     | NULL    |          
> >>       |
> >> | amount_type         | varchar(255)     | NO   |     | NULL    |          
> >>       |
> >> | old_balance         | double(15,8)     | NO   |     | NULL    |          
> >>       |
> >> | new_balance         | double(15,8)     | NO   |     | NULL    |          
> >>       |
> >> | remark              | text             | YES  |     | NULL    |          
> >>       |
> >> | order               | varchar(255)     | YES  |     | NULL    |          
> >>       |
> >> | form_state          | text             | YES  |     | NULL    |          
> >>       |
> >> | creator_user_id     | int(10) unsigned | NO   | MUL | NULL    |          
> >>       |
> >> | accounting_group_id | int(10) unsigned | NO   | MUL | NULL    |          
> >>       |
> >> | working_group_id    | int(10) unsigned | YES  | MUL | NULL    |          
> >>       |
> >> | resource_id         | int(10) unsigned | YES  | MUL | NULL    |          
> >>       |
> >> | transaction_type_id | int(10) unsigned | NO   | MUL | NULL    |          
> >>       |
> >> | start_time          | timestamp        | NO   |     | NULL    |          
> >>       |
> >> | end_time            | timestamp        | NO   | MUL | NULL    |          
> >>       |
> >> | created_at          | timestamp        | NO   |     | NULL    |          
> >>       |
> >> | updated_at          | timestamp        | NO   |     | NULL    |          
> >>       |
> >> | deleted_at          | timestamp        | YES  | MUL | NULL    |          
> >>       |
> >> +---------------------+------------------+------+-----+---------+----------------+
> >>
> >>
> >>
> >>
> >> MariaDB [cfms_accounting]> ANALYZE TABLE transactions;
> >> +------------------------------+---------+----------+----------+
> >> | Table                        | Op      | Msg_type | Msg_text |
> >> +------------------------------+---------+----------+----------+
> >> | cfms_accounting.transactions | analyze | status   | OK       |
> >> +------------------------------+---------+----------+----------+
> >> 1 row in set (0,107 sec)
> >>
> >>
> >> Server version: 10.3.39-MariaDB-0+deb10u2 Debian 10
> >>
> >>
> >> MariaDB [cfms_accounting]> SELECT count(*) from transactions;
> >> +----------+
> >> | count(*) |
> >> +----------+
> >> |  1912563 |
> >> +----------+
> >> 1 row in set (0,616 sec)
> >>
> >> MariaDB [cfms_accounting]> EXPLAIN select count(recipient) from 
> >> transactions;
> >> +------+-------------+--------------+------+---------------+------+---------+------+---------+-------+
> >> | id   | select_type | table        | type | possible_keys | key  | 
> >> key_len | ref  | rows    | Extra |
> >> +------+-------------+--------------+------+---------------+------+---------+------+---------+-------+
> >> |    1 | SIMPLE      | transactions | ALL  | NULL          | NULL | NULL   
> >>  | NULL | 1942730 |       |
> >> +------+-------------+--------------+------+---------------+------+---------+------+---------+-------+
> >> 1 row in set (0,002 sec)
> >>
> >>
> >> MariaDB [cfms_accounting]> select count(recipient) from transactions;
> >> +------------------+
> >> | count(recipient) |
> >> +------------------+
> >> |              419 |
> >> +------------------+
> >> 1 row in set (0,001 sec)
> >>
> >> Server version: 10.11.11-MariaDB-0+deb12u1 Debian 12
> >>
> >> MariaDB [cfms_accounting]> ANALYZE TABLE transactions;
> >> +------------------------------+---------+----------+----------+
> >> | Table                        | Op      | Msg_type | Msg_text |
> >> +------------------------------+---------+----------+----------+
> >> | cfms_accounting.transactions | analyze | status   | OK       |
> >> +------------------------------+---------+----------+----------+
> >> 1 row in set (0,058 sec)
> >>
> >>
> >> MariaDB [cfms_accounting]> select count(*) from transactions;
> >> +----------+
> >> | count(*) |
> >> +----------+
> >> |  1912563 |
> >> +----------+
> >> 1 row in set (0,333 sec)
> >>
> >> MariaDB [cfms_accounting]> EXPLAIN select count(recipient) from 
> >> transactions;
> >> +------+-------------+--------------+------+---------------+------+---------+------+---------+-------+
> >> | id   | select_type | table        | type | possible_keys | key  | 
> >> key_len | ref  | rows    | Extra |
> >> +------+-------------+--------------+------+---------------+------+---------+------+---------+-------+
> >> |    1 | SIMPLE      | transactions | ALL  | NULL          | NULL | NULL   
> >>  | NULL | 1779448 |       |
> >> +------+-------------+--------------+------+---------------+------+---------+------+---------+-------+
> >> 1 row in set (0,002 sec)
> >>
> >>
> >> MariaDB [cfms_accounting]> select count(recipient) from transactions;
> >> +------------------+
> >> | count(recipient) |
> >> +------------------+
> >> |              419 |
> >> +------------------+
> >> 1 row in set (4,778 sec)
> >>
> >>
> >>
> >> --
> >> Olivier Miquel
> >> Administrateur Système et Réseau
> >> Plate-forme technologique MRI
> >> Tel : 06.50.19.27.43
> >> Mail:[email protected]
> >>
> >> _______________________________________________
> >> discuss mailing list -- [email protected]
> >> To unsubscribe send an email to [email protected]
> >
> >
> --
> Olivier Miquel
> Administrateur Système et Réseau
> Plate-forme technologique MRI
> Tel : 06.50.19.27.43
> Mail:[email protected]
>


-- 
Gordan Bobic
Database Specialist, Shattered Silicon Ltd.
https://shatteredsilicon.net
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