Details
Minor Description
On a test database with 10m rows, with the exact same config, it takes about 10-15% longer to perform a "SELECT COUNT(*) FROM table;" on an InnoDB table having 10m rows.
Launch arguments : /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --user=mysql --open-files-limit=60000 --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock --port=3306
The my.cnf :
[mysqld]
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skip-external-locking
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max_connections = 250
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connect_timeout = 5
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wait_timeout = 600
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max_allowed_packet = 1G
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thread_cache_size = 128
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sort_buffer_size = 4M
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bulk_insert_buffer_size = 64M
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max_heap_table_size = 64M
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tmp_table_size = 64M
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myisam_recover = BACKUP
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key_buffer_size = 8M
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open-files-limit = 60000
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table_open_cache = 8000
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table_definition_cache = 8000
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myisam_sort_buffer_size = 128M
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concurrent_insert = 2
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read_rnd_buffer_size = 128M
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query_cache_size = 0
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query_cache_type = OFF
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log_warnings = 2
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slow_query_log = 0
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long_query_time = 4
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expire_logs_days = 10
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max_binlog_size = 150M
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default_storage_engine = InnoDB
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innodb_log_file_size = 2000M
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innodb_buffer_pool_size = 10G
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innodb_log_buffer_size = 16M
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innodb_file_per_table = 1
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delay_key_write = ON
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innodb_buffer_pool_instances = 8
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skip-name-resolve
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innodb_autoinc_lock_mode = 2
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event_scheduler = off
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group_concat_max_len = 5000
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innodb_file_format = Barracuda
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And here is the table structure :
CREATE TABLE `subscribers` (
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`subscriber_hash` varchar(8) NOT NULL,
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`subscriber_id` int(11) NOT NULL,
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`timestamp` datetime NOT NULL,
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`lastname` varchar(100) DEFAULT NULL,
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`firstname` varchar(100) DEFAULT NULL,
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`title` varchar(3) DEFAULT NULL,
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`creation_date` datetime DEFAULT NULL,
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`date_activation` datetime DEFAULT NULL,
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`birthdate` date DEFAULT NULL,
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`birthyear` int(4) DEFAULT NULL,
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`zipcode` varchar(10) DEFAULT NULL,
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`city` varchar(100) DEFAULT NULL,
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`country` varchar(100) DEFAULT NULL,
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`country_code` varchar(2) DEFAULT NULL,
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`cached_contract_id` int(11) DEFAULT NULL,
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`ISP` varchar(20) DEFAULT NULL,
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`isp_domain` varchar(96) DEFAULT NULL,
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`subscriber_cnt` int(4) DEFAULT NULL,
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PRIMARY KEY (`subscriber_hash`,`subscriber_id`,`timestamp`)
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) ENGINE=InnoDB DEFAULT CHARSET=utf8
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—
On a dry run on a Maria server that is only having this table on it and that is only running this test, on a system that has no real load while performing the tests, with XtraDB :
# time mysql test_database -e "SELECT COUNT(*) FROM subscribers;" && time mysql test_database -e "SELECT COUNT(*) FROM subscribers;" && time mysql test_database -e "SELECT COUNT(*) FROM subscribers;"
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+----------+
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| count(*) |
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+----------+
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| 10000000 |
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+----------+
|
|
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real 0m3.052s
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user 0m0.000s
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sys 0m0.010s
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+----------+
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| count(*) |
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+----------+
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| 10000000 |
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+----------+
|
|
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real 0m2.966s
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user 0m0.000s
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sys 0m0.000s
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+----------+
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| count(*) |
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+----------+
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| 10000000 |
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+----------+
|
|
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real 0m2.989s
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user 0m0.000s
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sys 0m0.000s
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—
With InnoDB plugin loaded instead of XtraDB (similar results are achieved when ran on MySQL 5.5.29) :
# time mysql test_database -e "SELECT COUNT(*) FROM subscribers;" && time mysql test_database -e "SELECT COUNT(*) FROM subscribers;" && time mysql test_database -e "SELECT COUNT(*) FROM subscribers;"
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+----------+
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| count(*) |
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+----------+
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| 10000000 |
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+----------+
|
|
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real 0m2.727s
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user 0m0.000s
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sys 0m0.000s
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+----------+
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| count(*) |
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+----------+
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| 10000000 |
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+----------+
|
|
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real 0m2.758s
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user 0m0.000s
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sys 0m0.000s
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+----------+
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| count(*) |
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+----------+
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| 10000000 |
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+----------+
|
|
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real 0m2.729s
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user 0m0.000s
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sys 0m0.000s
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