【发布时间】：2012-01-22 04:50:02
【问题描述】：
当重构我的 entriestable 并将 source 列拉到单独的 sources 表中时，我正在执行更新，您可以在下面的 slow_query_log 中看到它。
entries 表有 2 到 3 百万行。
# Time: 120121 22:24:44
# User@Host: bt_user[bt_user] @ localhost []
# Query_time: 3910.984208 Lock_time: 0.091942 Rows_sent: 0 Rows_examined: 2092977602
SET timestamp=1327202684;
update entries set source_id = 4 where source = 'SOME_SOURCE';
另一个糟糕的案例：
mysql> update entries set source_id = 7 where source = 'SOME_OTHER_SOURCE';
Query OK, 31270 rows affected (53 min 3.37 sec)
Rows matched: 31270 Changed: 31270 Warnings: 0
# Time: 120121 23:43:36
# User@Host: root[root] @ localhost []
# Query_time: 3183.845250 Lock_time: 0.000110 Rows_sent: 0 Rows_examined: 875871174
SET timestamp=1327207416;
update entries set source_id = 7 where source = 'SOME_OTHER_SOURCE';
这是一个更正常的情况：
mysql> update entries set source_id = 6 where source = 'YET_ANOTHER_SOURCE';
Query OK, 138592 rows affected (23.84 sec)
Rows matched: 138592 Changed: 138592 Warnings: 0
# Time: 120121 22:49:54
# User@Host: root[root] @ localhost []
# Query_time: 23.843946 Lock_time: 0.000149 Rows_sent: 0 Rows_examined: 554368
SET timestamp=1327204194;
update entries set source_id = 6 where source = 'YET_ANOTHER_SOURCE';
知道与非常大Rows_examined有什么关系吗？如果我能确定这一点，我也许会明白为什么有问题的交易需要一个多小时才能执行。
如果您需要更多信息，请直接询问，我会尽力提供。感谢您的帮助！
mysql> show create table entries\G
*************************** 1. row ***************************
Table: entries
Create Table: CREATE TABLE `entries` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`source` varchar(100) NOT NULL,
`source_id` int(10) unsigned NOT NULL DEFAULT '1000',
`ip` int(10) unsigned DEFAULT NULL,
`domain` varchar(255) DEFAULT NULL,
`url` varchar(2038) DEFAULT NULL,
`info` varchar(255) DEFAULT NULL,
`md5` varchar(32) NOT NULL,
`start_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`end_date` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
PRIMARY KEY (`id`),
KEY `both_date_source_index` (`start_date`,`end_date`,`source`),
KEY `source_index` (`source`),
KEY `ip_index` (`ip`),
KEY `domain_part_index` (`domain`(20)),
KEY `url_part_index` (`url`(30)),
KEY `md5_index` (`md5`)
) ENGINE=InnoDB AUTO_INCREMENT=2355472 DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
索引可能需要一些审查，但如果这会影响我的问题...
我的触发器（可能有更好的方法来做到这一点）：
mysql> show triggers\G
*************************** 1. row ***************************
Trigger: after_insert_count
Event: INSERT
Table: entries
Statement: BEGIN
IF NEW.ip IS NOT NULL THEN
IF (SELECT COUNT(*) FROM ip_counts WHERE ip = NEW.ip) > 0 THEN
UPDATE ip_counts SET count = count+1 WHERE ip = NEW.ip;
ELSE
INSERT INTO ip_counts (ip, count) VALUES (NEW.ip, 1);
END IF;
END IF;
IF NEW.domain IS NOT NULL THEN
IF (SELECT COUNT(*) FROM domain_counts WHERE domain = NEW.domain) > 0 THEN
UPDATE domain_counts SET count = count+1 WHERE domain = NEW.domain;
ELSE
INSERT INTO domain_counts (domain, count) VALUES (NEW.domain, 1);
END IF;
END IF;
IF NEW.url IS NOT NULL THEN
IF (SELECT COUNT(*) FROM url_counts WHERE url = NEW.url) > 0 THEN
UPDATE url_counts SET count = count+1 WHERE url = NEW.url;
ELSE
INSERT INTO url_counts (url, count) VALUES (NEW.url, 1);
END IF;
END IF;
END
Timing: AFTER
Created: NULL
sql_mode:
Definer: root@localhost
character_set_client: utf8
collation_connection: utf8_general_ci
Database Collation: utf8_general_ci
*************************** 2. row ***************************
Trigger: after_update_count
Event: UPDATE
Table: entries
Statement: BEGIN
IF OLD.ip IS NOT NULL THEN
UPDATE ip_counts SET count = count-1 WHERE ip = OLD.ip;
END IF;
IF OLD.domain IS NOT NULL THEN
UPDATE domain_counts SET count = count-1 WHERE domain = OLD.domain;
END IF;
IF OLD.url IS NOT NULL THEN
UPDATE url_counts SET count = count-1 WHERE url = OLD.url;
END IF;
IF NEW.ip IS NOT NULL THEN
IF (SELECT COUNT(*) FROM ip_counts WHERE ip = NEW.ip) > 0 THEN
UPDATE ip_counts SET count = count+1 WHERE ip = NEW.ip;
ELSE
INSERT INTO ip_counts (ip, count) VALUES (NEW.ip, 1);
END IF;
END IF;
IF NEW.domain IS NOT NULL THEN
IF (SELECT COUNT(*) FROM domain_counts WHERE domain = NEW.domain) > 0 THEN
UPDATE domain_counts SET count = count+1 WHERE domain = NEW.domain;
ELSE
INSERT INTO domain_counts (domain, count) VALUES (NEW.domain, 1);
END IF;
END IF;
IF NEW.url IS NOT NULL THEN
IF (SELECT COUNT(*) FROM url_counts WHERE url = NEW.url) > 0 THEN
UPDATE url_counts SET count = count+1 WHERE url = NEW.url;
ELSE
INSERT INTO url_counts (url, count) VALUES (NEW.url, 1);
END IF;
END IF;
END
Timing: AFTER
Created: NULL
sql_mode:
Definer: root@localhost
character_set_client: utf8
collation_connection: utf8_general_ci
Database Collation: utf8_general_ci
*************************** 3. row ***************************
Trigger: after_delete_count
Event: DELETE
Table: entries
Statement: BEGIN
IF OLD.ip IS NOT NULL THEN
UPDATE ip_counts SET count = count-1 WHERE ip = OLD.ip;
END IF;
IF OLD.domain IS NOT NULL THEN
UPDATE domain_counts SET count = count-1 WHERE domain = OLD.domain;
END IF;
IF OLD.url IS NOT NULL THEN
UPDATE url_counts SET count = count-1 WHERE url = OLD.url;
END IF;
END
Timing: AFTER
Created: NULL
sql_mode:
Definer: root@localhost
character_set_client: utf8
collation_connection: utf8_general_ci
Database Collation: utf8_general_ci
3 rows in set (0.00 sec)
【问题讨论】：
-
你的表中有外键约束吗？请发布
SHOW CREATE TABLE entries的输出。 -
@piotrm 用
show create table entries输出更新了我的问题。感谢您的关注！ -
任何触发器？
SHOW TRIGGERS WHERE `table`='entries' -
是的，我有触发器——可能就是这样！也许我可以在运行这些更新时尝试禁用它们？我现在正在粘贴它们...（ps：感谢您的支持，如果我在您的帮助下解决了这个问题，请务必发布答案，以便您获得信用！）
-
我会尝试遵循这个建议 stackoverflow.com/questions/6480074/mysql-disable-all-triggers 并告诉你进展如何。
标签： mysql