For completeness, can you specify which versions of MySQL & MariaDB you are comparing?

I assume both servers are running on the same hardware (not an SSD for MySQL and a hard drive for MariaDB), is that correct?
As this is a time-related query, did you run both queries using the same data & roughly the same time of day?

Also, since the query plans are the same and it's not a storage engine issue (myisam - myisam is still slower on MariaDB's side), I need to check if there was anything Windows specific that was changed in MariaDB.

Vicențiu

On Tue, 2 Jun 2020 at 13:58, Ling, Andy <Andy.Ling@grassvalley.com> wrote:

mysql> EXPLAIN SELECT r.rushid FROM rushes r LEFT JOIN browse b ON r.rushID = b.rushID WHERE b.rushID IS NULL AND r.updated < NOW() - INTERVAL 1 DAY;

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

| id | select_type | table | type | possible_keys | key          | key_len | ref                 | rows   | Extra                                |

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

| 1 | SIMPLE      | r     | ALL | NULL          | NULL         | NULL    | NULL                | 784286 | Using where                          |

| 1 | SIMPLE      | b     | ref | rushid_start | rushid_start | 96      | quentin_v3.r.rushID |     10 | Using where; Using index; Not exists |

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

2 rows in set (0.00 sec)

MariaDB [quentin_v3]> EXPLAIN SELECT r.rushid FROM rushes r LEFT JOIN browse b ON r.rushID = b.rushID WHERE b.rushID IS NULL AND r.updated < NOW() - INTERVAL 1 DAY;

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

| id   | select_type | table | type | possible_keys | key          | key_len | ref                 | rows   | Extra                                |

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

|    1 | SIMPLE      | r     | ALL | NULL          | NULL         | NULL    | NULL                | 784286 | Using where                          |

|    1 | SIMPLE      | b     | ref | rushid_start | rushid_start | 96      | quentin_v3.r.rushID | 10     | Using where; Using index; Not exists |

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

2 rows in set (0.001 sec)

Look pretty similar.

Regards

Andy Ling

From: Maria-discuss [mailto:maria-discuss-bounces+andy.ling=grassvalley.com@lists.launchpad.net] On Behalf Of Gordan Bobic
Sent: Tue 02 June 2020 09:44
Cc: Mailing-List mariadb <maria-discuss@lists.launchpad.net>
Subject: Re: [Maria-discuss] [EXTERNAL] Re: Poor performance compared to MySQL

Can you post EXPLAIN from both? Is it exactly the same?

On Tue, 2 Jun 2020, 09:21 Ling, Andy, <Andy.Ling@grassvalley.com> wrote:

MariaDB is still significantly slower.

From: Roberto Spadim [mailto:roberto@spadim.com.br]
Sent: Mon 01 June 2020 18:33
To: Ling, Andy <Andy.Ling@grassvalley.com>
Cc: Mailing-List mariadb <maria-discuss@lists.launchpad.net>
Subject: [EXTERNAL] Re: [Maria-discuss] Poor performance compared to MySQL

External Message:Use caution before opening links or attachments

what happen when comparing myisam-myisam?

Em seg., 1 de jun. de 2020 às 12:51, Ling, Andy <Andy.Ling@grassvalley.com> escreveu:

I am looking at switching from MySQL to MariaDB and have been comparing the performance of the two.

I am using the same databases on the same Windows machine and running queries using MySQL and MariaDB

and I am finding that MariaDB is 6 times slower. A query that takes 5 seconds on MySQL is taking 28 seconds on MariaDB.

I am hoping I have some configuration wrong, so I looking for some help to work out what needs changing.

One of the problem queries is a join between two tables. Analyzing the query gives..

ANALYZE FORMAT=JSON SELECT r.rushid FROM rushes r LEFT JOIN browse b ON r.rushID = b.rushID WHERE b.rushID IS NULL AND r.updated < NOW() - INTERVAL 1 DAY;

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

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

| ANALYZE

                                                                                       |

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

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

| {

"query_block": {

    "select_id": 1,

    "r_loops": 1,

    "r_total_time_ms": 107974,

    "table": {

      "table_name": "r",

      "access_type": "ALL",

      "r_loops": 1,

      "rows": 784286,

      "r_rows": 784286,

      "r_total_time_ms": 245.5,

      "filtered": 100,

      "r_filtered": 100,

      "attached_condition": "r.updated < '2020-05-31 16:35:59'"

    },

    "table": {

      "table_name": "b",

      "access_type": "ref",

      "possible_keys": ["rushid_start", "rushid"],

      "key": "rushid",

      "key_length": "96",

      "used_key_parts": ["rushID"],

      "ref": ["quentin_v3afp.r.rushID"],

      "r_loops": 784286,

      "rows": 10,

      "r_rows": 1,

      "r_total_time_ms": 106252,

      "filtered": 100,

      "r_filtered": 100,

      "attached_condition": "trigcond(b.rushID is null)",

      "using_index": true,

      "not_exists": true

   }

}

} |

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

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

1 row in set (1 min 48.244 sec)

The table has been converted to the Aria engine from MyISAM. The my.ini file has had the following added/changed..

#Not using MyISAM so save memory

key_buffer_size=64k

#Setting to improve Aria performance

aria_pagecache_buffer_size=4007M

tmp_table_size=35M

max_heap_table_size=35M

Thanks for any help.

Andy Ling

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--

Roberto Spadim
SPAEmpresarial - Software ERP/Scada

Eng. Automação e Controle, Eng. Financeira

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