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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