基本上，我们有一个很大的生产问题，我们的 sql 查询在结束前花费了 300 多秒。
我们使用 Mysql 作为 SQL 服务器，我们的表使用 MyISAM。
有问题的查询是两个表之间的基本查询，具有排序和分组依据。问题是每个表都有超过 3000 万行。
这是这个查询的一个假例子:
SELECT
i.id_stat as idStat,
SUM(srv0.duree_st) AS dureeAppelTotale,
_date as dateI,
DATE_FORMAT(srv0._date,'%d/%m') AS datekey,
DATE_FORMAT(_date,'%d%m%Y') AS datekeyGroup,
heure,
SUM(srv0.nombre_st) AS nbAppel
FROM ids_stat i , SRV201606 srv0
WHERE i.id_rubrique = srv0.id_rubrique
AND i.id_appli = 24071
AND srv0._date >= '2016-06-01 00:00:00'
AND srv0._date <= '2016-07-01 00:00:00'
GROUP BY id_stat, datekeyGroup, heure
ORDER BY _date
ids_stat 表上的索引是:
show index from ids_stat;
+----------+------------+---------------------+--------------+---------------+-----------+-------------+----------+--------+------+------------+---------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment |
+----------+------------+---------------------+--------------+---------------+-----------+-------------+----------+--------+------+------------+---------+
| ids_stat | 0 | PRIMARY | 1 | id_rubrique | A | 7435537 | NULL | NULL | | BTREE | |
| ids_stat | 1 | id_appli_index | 1 | id_appli | A | 13593 | NULL | NULL | | BTREE | |
| ids_stat | 1 | date_creation_index | 1 | date_creation | A | 2478512 | NULL | NULL | | BTREE | |
在 SRV0 表上，索引是:
show index from SRV201606;
+-----------+------------+----------------+--------------+----------------+-----------+-------------+----------+--------+------+------------+---------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment |
+-----------+------------+----------------+--------------+----------------+-----------+-------------+----------+--------+------+------------+---------+
| SRV201606 | 0 | PRIMARY | 1 | _date | A | NULL | NULL | NULL | | BTREE | |
| SRV201606 | 0 | PRIMARY | 2 | heure | A | NULL | NULL | NULL | | BTREE | |
| SRV201606 | 0 | PRIMARY | 3 | minute | A | NULL | NULL | NULL | | BTREE | |
| SRV201606 | 0 | PRIMARY | 4 | id_plaque | A | NULL | NULL | NULL | | BTREE | |
| SRV201606 | 0 | PRIMARY | 5 | id_rubrique | A | NULL | NULL | NULL | | BTREE | |
| SRV201606 | 0 | PRIMARY | 6 | id_combinaison | A | 27472765 | NULL | NULL | | BTREE | |
| SRV201606 | 1 | id_rubrique | 1 | id_rubrique | A | NULL | NULL | NULL | | BTREE | |
| SRV201606 | 1 | id_combinaison | 1 | id_combinaison | A | NULL | NULL | NULL | | BTREE | |
此外，这里是查询的解释:
+----+-------------+-------+------+------------------------+----------------+---------+-----------------------------+------+---------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+------------------------+----------------+---------+-----------------------------+------+---------------------------------+
| 1 | SIMPLE | i | ref | PRIMARY,id_appli_index | id_appli_index | 2 | const | 153 | Using temporary; Using filesort |
| 1 | SIMPLE | srv0 | ref | PRIMARY,id_rubrique | id_rubrique | 8 | StatVoxProdV2.i.id_rubrique | 16 | Using where |
我们还了解到，这些使用 where 进行的旧联接是无害的，因为它们被 sql 引擎转录为内部联接。
你能帮我们找到调整 mysql 服务器的方法吗？有什么配置可以帮助我们解决问题吗？
非常感谢
[编辑] 正如评论中所问，这是他的版本:
选择版本();
+------------+
| VERSION() |
+------------+
| 5.0.45-log |
服务器变量:
show Variables;
+---------------------------------+----------------------------------+
| Variable_name | Value |
+---------------------------------+----------------------------------+
| auto_increment_increment | 1 |
| auto_increment_offset | 1 |
| automatic_sp_privileges | ON |
| back_log | 50 |
| basedir | /usr/local/ |
| binlog_cache_size | 32768 |
| bulk_insert_buffer_size | 8388608 |
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | latin1 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir | /usr/local/share/mysql/charsets/ |
| collation_connection | utf8_general_ci |
| collation_database | latin1_swedish_ci |
| collation_server | latin1_swedish_ci |
| completion_type | 0 |
| concurrent_insert | 1 |
| connect_timeout | 5 |
| datadir | THEDATADIR |
| date_format | %Y-%m-%d |
| datetime_format | %Y-%m-%d %H:%i:%s |
| default_week_format | 0 |
| delay_key_write | ON |
| delayed_insert_limit | 100 |
| delayed_insert_timeout | 300 |
| delayed_queue_size | 1000 |
| div_precision_increment | 4 |
| engine_condition_pushdown | OFF |
| expire_logs_days | 32 |
| flush | OFF |
| flush_time | 0 |
| ft_boolean_syntax | + -><()~*:""&| |
| ft_max_word_len | 84 |
| ft_min_word_len | 4 |
| ft_query_expansion_limit | 20 |
| ft_stopword_file | (built-in) |
| group_concat_max_len | 1024 |
| have_archive | NO |
| have_bdb | NO |
| have_blackhole_engine | NO |
| have_compress | YES |
| have_crypt | YES |
| have_csv | NO |
| have_dynamic_loading | YES |
| have_example_engine | NO |
| have_federated_engine | NO |
| have_geometry | YES |
| have_innodb | DISABLED |
| have_isam | NO |
| have_merge_engine | YES |
| have_ndbcluster | NO |
| have_openssl | NO |
| have_ssl | NO |
| have_query_cache | YES |
| have_raid | NO |
| have_rtree_keys | YES |
| have_symlink | YES |
| hostname | THEHOSTNAME |
| init_connect | |
| init_file | |
| init_slave | |
| innodb_additional_mem_pool_size | 1048576 |
| innodb_autoextend_increment | 8 |
| innodb_buffer_pool_awe_mem_mb | 0 |
| innodb_buffer_pool_size | 1048576 |
| innodb_checksums | ON |
| innodb_commit_concurrency | 0 |
| innodb_concurrency_tickets | 500 |
| innodb_data_file_path | |
| innodb_data_home_dir | |
| innodb_doublewrite | ON |
| innodb_fast_shutdown | 1 |
| innodb_file_io_threads | 4 |
| innodb_file_per_table | OFF |
| innodb_flush_log_at_trx_commit | 1 |
| innodb_flush_method | |
| innodb_force_recovery | 0 |
| innodb_lock_wait_timeout | 50 |
| innodb_locks_unsafe_for_binlog | OFF |
| innodb_log_arch_dir | |
| innodb_log_archive | OFF |
| innodb_log_buffer_size | 1048576 |
| innodb_log_file_size | 5242880 |
| innodb_log_files_in_group | 2 |
| innodb_log_group_home_dir | |
| innodb_max_dirty_pages_pct | 90 |
| innodb_max_purge_lag | 0 |
| innodb_mirrored_log_groups | 1 |
| innodb_open_files | 300 |
| innodb_rollback_on_timeout | OFF |
| innodb_support_xa | ON |
| innodb_sync_spin_loops | 20 |
| innodb_table_locks | ON |
| innodb_thread_concurrency | 8 |
| innodb_thread_sleep_delay | 10000 |
| interactive_timeout | 28800 |
| join_buffer_size | 131072 |
| key_buffer_size | 402653184 |
| key_cache_age_threshold | 300 |
| key_cache_block_size | 1024 |
| key_cache_division_limit | 100 |
| language | /usr/local/share/mysql/english/ |
| large_files_support | ON |
| large_page_size | 0 |
| large_pages | OFF |
| lc_time_names | en_US |
| license | GPL |
| local_infile | ON |
| locked_in_memory | OFF |
| log | OFF |
| log_bin | ON |
| log_bin_trust_function_creators | OFF |
| log_error | |
| log_queries_not_using_indexes | OFF |
| log_slave_updates | OFF |
| log_slow_queries | ON |
| log_warnings | 1 |
| long_query_time | 10 |
| low_priority_updates | OFF |
| lower_case_file_system | OFF |
| lower_case_table_names | 0 |
| max_allowed_packet | 1047552 |
| max_binlog_cache_size | 4294967295 |
| max_binlog_size | 104857600 |
| max_connect_errors | 10 |
| max_connections | 100 |
| max_delayed_threads | 20 |
| max_error_count | 64 |
| max_heap_table_size | 134217728 |
| max_insert_delayed_threads | 20 |
| max_join_size | 4294967295 |
| max_length_for_sort_data | 1024 |
| max_prepared_stmt_count | 16382 |
| max_relay_log_size | 0 |
| max_seeks_for_key | 4294967295 |
| max_sort_length | 1024 |
| max_sp_recursion_depth | 0 |
| max_tmp_tables | 32 |
| max_user_connections | 0 |
| max_write_lock_count | 4294967295 |
| multi_range_count | 256 |
| myisam_data_pointer_size | 6 |
| myisam_max_sort_file_size | 2147483647 |
| myisam_recover_options | OFF |
| myisam_repair_threads | 1 |
| myisam_sort_buffer_size | 67108864 |
| myisam_stats_method | nulls_unequal |
| net_buffer_length | 16384 |
| net_read_timeout | 30 |
| net_retry_count | 10 |
| net_write_timeout | 60 |
| new | OFF |
| old_passwords | OFF |
| open_files_limit | 4096 |
| optimizer_prune_level | 1 |
| optimizer_search_depth | 62 |
| pid_file | /usr2/mysql/var/run/mysqld.pid |
| port | 3306 |
| preload_buffer_size | 32768 |
| profiling | OFF |
| profiling_history_size | 15 |
| protocol_version | 10 |
| query_alloc_block_size | 8192 |
| query_cache_limit | 1048576 |
| query_cache_min_res_unit | 4096 |
| query_cache_size | 33554432 |
| query_cache_type | ON |
| query_cache_wlock_invalidate | OFF |
| query_prealloc_size | 8192 |
| range_alloc_block_size | 2048 |
| read_buffer_size | 2093056 |
| read_only | OFF |
| read_rnd_buffer_size | 8384512 |
| relay_log_purge | ON |
| relay_log_space_limit | 0 |
| rpl_recovery_rank | 0 |
| secure_auth | OFF |
| secure_file_priv | |
| server_id | 2 |
| skip_external_locking | ON |
| skip_networking | OFF |
| skip_show_database | OFF |
| slave_compressed_protocol | OFF |
| slave_load_tmpdir | /usr2/mysql/tmp/ |
| slave_net_timeout | 3600 |
| slave_skip_errors | ALL |
| slave_transaction_retries | 10 |
| slow_launch_time | 2 |
| socket | /usr2/mysql/var/run/mysqld.sock |
| sort_buffer_size | 2097144 |
| sql_big_selects | ON |
| sql_mode | |
| sql_notes | ON |
| sql_warnings | OFF |
| ssl_ca | |
| ssl_capath | |
| ssl_cert | |
| ssl_cipher | |
| ssl_key | |
| storage_engine | MyISAM |
| sync_binlog | 0 |
| sync_frm | ON |
| system_time_zone | CET |
| table_cache | 512 |
| table_lock_wait_timeout | 50 |
| table_type | MyISAM |
| thread_cache_size | 8 |
| thread_stack | 196608 |
| time_format | %H:%i:%s |
| time_zone | SYSTEM |
| timed_mutexes | OFF |
| tmp_table_size | 134217728 |
| tmpdir | /usr2/mysql/tmp/ |
| transaction_alloc_block_size | 8192 |
| transaction_prealloc_size | 4096 |
| tx_isolation | REPEATABLE-READ |
| updatable_views_with_limit | YES |
| version | 5.0.45-log |
| version_comment | Source distribution |
| version_compile_machine | i686 |
| version_compile_os | pc-linux-gnu |
| wait_timeout | 28800 |
ids_stat 模式:
SHOW CREATE TABLE ids_stat;
CREATE TABLE `ids_stat` (
`id_rubrique` bigint(20) NOT NULL default '0',
`id_stat` int(10) default NULL,
`id_appli` smallint(5) unsigned NOT NULL default '0',
`nom_rubrique` varchar(240) NOT NULL,
`date_creation` timestamp NOT NULL default CURRENT_TIMESTAMP,
PRIMARY KEY (`id_rubrique`),
KEY `id_appli_index` (`id_appli`),
KEY `date_creation_index` (`date_creation`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
以及 SRV0 示例模式:
CREATE TABLE `SRV201606` (
`id_rubrique` bigint(20) NOT NULL default '0',
`id_plaque` tinyint(3) unsigned NOT NULL default '0',
`id_combinaison` smallint(5) unsigned NOT NULL default '0',
`_date` date NOT NULL default '0000-00-00',
`heure` tinyint(3) NOT NULL default '0',
`minute` tinyint(3) NOT NULL default '0',
`nombre_entree` mediumint(8) unsigned default '0',
`nombre_st` mediumint(8) unsigned default NULL,
`duree_st` mediumint(8) unsigned default NULL,
`flag` tinyint(3) unsigned NOT NULL default '0',
PRIMARY KEY (`_date`,`heure`,`minute`,`id_plaque`,`id_rubrique`,`id_combinaison`),
KEY `id_rubrique` (`id_rubrique`),
KEY `id_combinaison` (`id_combinaison`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
最佳答案
这不是我完成的答案!
但是你能不能只在你的大表上运行这个查询并告诉我执行时间和它的解释。
更改表 SRV201606 添加 key idx_rubrique_date (_date,id_rubrique);
SELECT
i.*,
SUM(srv0.duree_st) AS dureeAppelTotale,
srv0._date AS dateI,
DATE_FORMAT(srv0._date,'%d/%m') AS datekey,
DATE_FORMAT(_date,'%d%m%Y') AS datekeyGroup,
heure,
SUM(srv0.nombre_st) AS nbAppel
FROM (
SELECT
id_rubrique
, id_stat
FROM ids_stat
WHERE
id_appli = 24071
GROUP BY id_stat
) AS i
LEFT JOIN SRV201606 srv0 ON i.id_rubrique = srv0.id_rubrique
WHERE
srv0._date >= '2016-06-01'
AND
srv0._date <= '2016-07-01'
GROUP BY id_stat, _date, heure
ORDER BY _date;
关于mysql - MySQL 重载时的性能问题，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37965282/