MySQL Forums
Forum List  »  Performance

Hanging on copying to tmp table
Posted by: Brian Dalby
Date: April 23, 2012 06:55AM

Hi all,

I have a database with a lot of traffic on one single table.

Sometimes it hangs on "copying to tmp table", and also "sending data", but mostly on "copying...".

It does not happen everyday, and I have not found a way to recreate it, so I cannot explain why it happens.

I have the following information:

SHOW CREATE TABLE test_testcase;

'test_testcase', 'CREATE TABLE `test_testcase` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`name` varchar(200) NOT NULL,
`status_id` int(10) unsigned DEFAULT NULL,
`steps` text,
`description` text,
`priority_id` int(10) unsigned DEFAULT NULL,
`lft` int(10) unsigned NOT NULL,
`rgt` int(10) unsigned NOT NULL,
`known_error` varchar(100) DEFAULT NULL,
`dependent_from_id` int(10) unsigned DEFAULT NULL,
`is_folder` tinyint(4) NOT NULL DEFAULT '0',
`latest_user_edit` varchar(45) NOT NULL,
`bug` text,
`creation_time` datetime NOT NULL DEFAULT '1000-01-01 00:00:00',
PRIMARY KEY (`id`),
KEY `indx_testcase_rgt` (`rgt`),
KEY `indx_testcase_lft` (`lft`),
KEY `tst_testcase_status` (`status_id`),
KEY `tst_testcase_priority` (`priority_id`),
KEY `tst_testcase_dependencies` (`dependent_from_id`),
CONSTRAINT `tst_testcase_priority` FOREIGN KEY (`priority_id`) REFERENCES `test_priority` (`id`) ON DELETE SET NULL ON UPDATE NO ACTION,
CONSTRAINT `tst_testcase_status` FOREIGN KEY (`status_id`) REFERENCES `test_status` (`id`) ON DELETE SET NULL ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=5394 DEFAULT CHARSET=latin1'




SHOW TABLE STATUS LIKE 'test_testcase';

'test_testcase', 'InnoDB', 10, 'Compact', 8745, 301, 2637824, 0, 4521984, 18874368, 5394, '2012-02-13 12:05:27', '', '', 'latin1_swedish_ci', , '', ''



EXPLAIN
SELECT SQL_CACHE
`node`.`is_folder`
, `node`.`id`
, `node`.`name`
, (COUNT(`parent`.`name`)-1) AS `level`
, `node`.`lft`
, `node`.`rgt`
, `node`.`status_id`
, `node`.`bug`
, `node`.`known_error`
FROM `test_testcase` AS `node`, `test_testcase` AS `parent`
WHERE `node`.`lft` BETWEEN `parent`.`lft` AND `parent`.`rgt`
GROUP BY `node`.`lft`
ORDER BY `node`.`lft`;

1, 'SIMPLE', 'node', 'ALL', 'indx_testcase_lft', '', '', '', 8745, 'Using temporary; Using filesort'
1, 'SIMPLE', 'parent', 'ALL', 'indx_testcase_rgt,indx_testcase_lft', '', '', '', 8745, 'Range checked for each record (index map: 0x6)'




SHOW VARIABLES LIKE '%buffer%';

'bulk_insert_buffer_size', '8388608'
'innodb_buffer_pool_size', '2621440000'
'innodb_log_buffer_size', '1048576'
'join_buffer_size', '8388608'
'key_buffer_size', '33554432'
'myisam_sort_buffer_size', '8388608'
'net_buffer_length', '16384'
'preload_buffer_size', '32768'
'read_buffer_size', '2097152'
'read_rnd_buffer_size', '16777216'
'sort_buffer_size', '8388608'
'sql_buffer_result', 'OFF'

It makes everything hanging and perfomance becomes very slow, can anyone help with a suggestion to solve this problem?

Options: ReplyQuote


Subject
Views
Written By
Posted
Hanging on copying to tmp table
6399
April 23, 2012 06:55AM
3101
April 24, 2012 10:16AM
2472
April 24, 2012 02:44PM
2029
April 25, 2012 01:08PM
2176
April 25, 2012 08:43PM
2077
April 26, 2012 12:35AM
2366
April 26, 2012 02:17AM
1636
April 27, 2012 07:02AM
1879
April 28, 2012 01:37PM
1927
April 28, 2012 02:00PM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.