MySQL « Почему WHERE … IS NULL так медленно работает и как можно обойтись без него?

Добрый день уважаемые знатоки sql.

Есть две таблицы.
Первая:
/** * GeSHi (C) 2004 - 2007 Nigel McNie, 2007 - 2008 Benny Baumann * (http://qbnz.com/highlighter/ and http://geshi.org/) */ .mysql.geshi_code {font-family:monospace;} .mysql.geshi_code .imp {font-weight: bold; color: red;} .mysql.geshi_code .kw1 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw2 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw3 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw4 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw5 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw6 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw7 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw8 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw9 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw10 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw11 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw12 {color: #009900;} .mysql.geshi_code .kw13 {color: #000099;} .mysql.geshi_code .kw14 {color: #000099;} .mysql.geshi_code .kw15 {color: #000099;} .mysql.geshi_code .kw16 {color: #000099;} .mysql.geshi_code .kw17 {color: #000099;} .mysql.geshi_code .kw18 {color: #000099;} .mysql.geshi_code .kw19 {color: #000099;} .mysql.geshi_code .kw20 {color: #000099;} .mysql.geshi_code .kw21 {color: #000099;} .mysql.geshi_code .kw22 {color: #000099;} .mysql.geshi_code .kw23 {color: #000099;} .mysql.geshi_code .kw24 {color: #000099;} .mysql.geshi_code .kw25 {color: #000099;} .mysql.geshi_code .kw26 {color: #000099;} .mysql.geshi_code .kw27 {color: #00CC00;} .mysql.geshi_code .coMULTI {color: #808000; font-style: italic;} .mysql.geshi_code .co1 {color: #808080; font-style: italic;} .mysql.geshi_code .co2 {color: #808080; font-style: italic;} .mysql.geshi_code .es0 {color: #004000; font-weight: bold;} .mysql.geshi_code .es1 {color: #008080; font-weight: bold;} .mysql.geshi_code .br0 {color: #FF00FF;} .mysql.geshi_code .sy1 {color: #CC0099;} .mysql.geshi_code .sy2 {color: #000033;} .mysql.geshi_code .st0 {color: #008000;} .mysql.geshi_code .nu0 {color: #008080;} .mysql.geshi_code span.xtra { display:block; }

SHOW CREATE TABLE call_call

CREATE TABLE `call_call` (
`id_call` bigint(20) NOT NULL auto_increment,
 ...
 `reason_call` varchar(255) collate utf8_unicode_ci NOT NULL,
 `active_call` int(2) default NULL,
 PRIMARY KEY  (`id_call`)
) ENGINE=MyISAM AUTO_INCREMENT=127271 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
 


Вторая:
/** * GeSHi (C) 2004 - 2007 Nigel McNie, 2007 - 2008 Benny Baumann * (http://qbnz.com/highlighter/ and http://geshi.org/) */ .mysql.geshi_code {font-family:monospace;} .mysql.geshi_code .imp {font-weight: bold; color: red;} .mysql.geshi_code .kw1 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw2 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw3 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw4 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw5 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw6 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw7 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw8 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw9 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw10 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw11 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw12 {color: #009900;} .mysql.geshi_code .kw13 {color: #000099;} .mysql.geshi_code .kw14 {color: #000099;} .mysql.geshi_code .kw15 {color: #000099;} .mysql.geshi_code .kw16 {color: #000099;} .mysql.geshi_code .kw17 {color: #000099;} .mysql.geshi_code .kw18 {color: #000099;} .mysql.geshi_code .kw19 {color: #000099;} .mysql.geshi_code .kw20 {color: #000099;} .mysql.geshi_code .kw21 {color: #000099;} .mysql.geshi_code .kw22 {color: #000099;} .mysql.geshi_code .kw23 {color: #000099;} .mysql.geshi_code .kw24 {color: #000099;} .mysql.geshi_code .kw25 {color: #000099;} .mysql.geshi_code .kw26 {color: #000099;} .mysql.geshi_code .kw27 {color: #00CC00;} .mysql.geshi_code .coMULTI {color: #808000; font-style: italic;} .mysql.geshi_code .co1 {color: #808080; font-style: italic;} .mysql.geshi_code .co2 {color: #808080; font-style: italic;} .mysql.geshi_code .es0 {color: #004000; font-weight: bold;} .mysql.geshi_code .es1 {color: #008080; font-weight: bold;} .mysql.geshi_code .br0 {color: #FF00FF;} .mysql.geshi_code .sy1 {color: #CC0099;} .mysql.geshi_code .sy2 {color: #000033;} .mysql.geshi_code .st0 {color: #008000;} .mysql.geshi_code .nu0 {color: #008080;} .mysql.geshi_code span.xtra { display:block; }

SHOW CREATE TABLE call_operation

CREATE TABLE `call_operation` (
 `id_operation` bigint(20) unsigned NOT NULL auto_increment,
 `id_call_operation` bigint(20) unsigned NOT NULL,
 ...
 `result_operation` varchar(1) collate utf8_unicode_ci NOT NULL,
 PRIMARY KEY  (`id_operation`)
) ENGINE=MyISAM AUTO_INCREMENT=5782 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
 


Есть проблемный запрос который отрабатывает за 0.3568 сек извлекая около 500 записей, выбрав только те записи из основной таблицы, у которых нет ни одной записи в подчиненной таблице:
/** * GeSHi (C) 2004 - 2007 Nigel McNie, 2007 - 2008 Benny Baumann * (http://qbnz.com/highlighter/ and http://geshi.org/) */ .mysql.geshi_code {font-family:monospace;} .mysql.geshi_code .imp {font-weight: bold; color: red;} .mysql.geshi_code .kw1 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw2 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw3 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw4 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw5 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw6 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw7 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw8 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw9 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw10 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw11 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw12 {color: #009900;} .mysql.geshi_code .kw13 {color: #000099;} .mysql.geshi_code .kw14 {color: #000099;} .mysql.geshi_code .kw15 {color: #000099;} .mysql.geshi_code .kw16 {color: #000099;} .mysql.geshi_code .kw17 {color: #000099;} .mysql.geshi_code .kw18 {color: #000099;} .mysql.geshi_code .kw19 {color: #000099;} .mysql.geshi_code .kw20 {color: #000099;} .mysql.geshi_code .kw21 {color: #000099;} .mysql.geshi_code .kw22 {color: #000099;} .mysql.geshi_code .kw23 {color: #000099;} .mysql.geshi_code .kw24 {color: #000099;} .mysql.geshi_code .kw25 {color: #000099;} .mysql.geshi_code .kw26 {color: #000099;} .mysql.geshi_code .kw27 {color: #00CC00;} .mysql.geshi_code .coMULTI {color: #808000; font-style: italic;} .mysql.geshi_code .co1 {color: #808080; font-style: italic;} .mysql.geshi_code .co2 {color: #808080; font-style: italic;} .mysql.geshi_code .es0 {color: #004000; font-weight: bold;} .mysql.geshi_code .es1 {color: #008080; font-weight: bold;} .mysql.geshi_code .br0 {color: #FF00FF;} .mysql.geshi_code .sy1 {color: #CC0099;} .mysql.geshi_code .sy2 {color: #000033;} .mysql.geshi_code .st0 {color: #008000;} .mysql.geshi_code .nu0 {color: #008080;} .mysql.geshi_code span.xtra { display:block; }

SELECT `call_call`.*, `call_operation`.`id_operation`
FROM `call_call`
LEFT JOIN `call_operation` ON `call_operation`.`id_call_operation` = `call_call`.`id_call`
WHERE `active_call` = '1' AND `id_operation` IS NULL
 


Explain:
/** * GeSHi (C) 2004 - 2007 Nigel McNie, 2007 - 2008 Benny Baumann * (http://qbnz.com/highlighter/ and http://geshi.org/) */ .mysql.geshi_code {font-family:monospace;} .mysql.geshi_code .imp {font-weight: bold; color: red;} .mysql.geshi_code .kw1 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw2 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw3 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw4 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw5 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw6 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw7 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw8 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw9 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw10 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw11 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw12 {color: #009900;} .mysql.geshi_code .kw13 {color: #000099;} .mysql.geshi_code .kw14 {color: #000099;} .mysql.geshi_code .kw15 {color: #000099;} .mysql.geshi_code .kw16 {color: #000099;} .mysql.geshi_code .kw17 {color: #000099;} .mysql.geshi_code .kw18 {color: #000099;} .mysql.geshi_code .kw19 {color: #000099;} .mysql.geshi_code .kw20 {color: #000099;} .mysql.geshi_code .kw21 {color: #000099;} .mysql.geshi_code .kw22 {color: #000099;} .mysql.geshi_code .kw23 {color: #000099;} .mysql.geshi_code .kw24 {color: #000099;} .mysql.geshi_code .kw25 {color: #000099;} .mysql.geshi_code .kw26 {color: #000099;} .mysql.geshi_code .kw27 {color: #00CC00;} .mysql.geshi_code .coMULTI {color: #808000; font-style: italic;} .mysql.geshi_code .co1 {color: #808080; font-style: italic;} .mysql.geshi_code .co2 {color: #808080; font-style: italic;} .mysql.geshi_code .es0 {color: #004000; font-weight: bold;} .mysql.geshi_code .es1 {color: #008080; font-weight: bold;} .mysql.geshi_code .br0 {color: #FF00FF;} .mysql.geshi_code .sy1 {color: #CC0099;} .mysql.geshi_code .sy2 {color: #000033;} .mysql.geshi_code .st0 {color: #008000;} .mysql.geshi_code .nu0 {color: #008080;} .mysql.geshi_code span.xtra { display:block; }

id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE call_call ALL NULL NULL NULL NULL 109590 Using where
1 SIMPLE call_operation ALL NULL NULL NULL NULL 5717 Using where; Not exists
 


Если из условия этого запроса убрать условие с NULL и заменить на (`id_operation`>0), то есть выбрать записи из главной таблицы, у которых есть соответствующие записи в подчиненной, то запрос вида:

/** * GeSHi (C) 2004 - 2007 Nigel McNie, 2007 - 2008 Benny Baumann * (http://qbnz.com/highlighter/ and http://geshi.org/) */ .mysql.geshi_code {font-family:monospace;} .mysql.geshi_code .imp {font-weight: bold; color: red;} .mysql.geshi_code .kw1 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw2 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw3 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw4 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw5 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw6 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw7 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw8 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw9 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw10 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw11 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw12 {color: #009900;} .mysql.geshi_code .kw13 {color: #000099;} .mysql.geshi_code .kw14 {color: #000099;} .mysql.geshi_code .kw15 {color: #000099;} .mysql.geshi_code .kw16 {color: #000099;} .mysql.geshi_code .kw17 {color: #000099;} .mysql.geshi_code .kw18 {color: #000099;} .mysql.geshi_code .kw19 {color: #000099;} .mysql.geshi_code .kw20 {color: #000099;} .mysql.geshi_code .kw21 {color: #000099;} .mysql.geshi_code .kw22 {color: #000099;} .mysql.geshi_code .kw23 {color: #000099;} .mysql.geshi_code .kw24 {color: #000099;} .mysql.geshi_code .kw25 {color: #000099;} .mysql.geshi_code .kw26 {color: #000099;} .mysql.geshi_code .kw27 {color: #00CC00;} .mysql.geshi_code .coMULTI {color: #808000; font-style: italic;} .mysql.geshi_code .co1 {color: #808080; font-style: italic;} .mysql.geshi_code .co2 {color: #808080; font-style: italic;} .mysql.geshi_code .es0 {color: #004000; font-weight: bold;} .mysql.geshi_code .es1 {color: #008080; font-weight: bold;} .mysql.geshi_code .br0 {color: #FF00FF;} .mysql.geshi_code .sy1 {color: #CC0099;} .mysql.geshi_code .sy2 {color: #000033;} .mysql.geshi_code .st0 {color: #008000;} .mysql.geshi_code .nu0 {color: #008080;} .mysql.geshi_code span.xtra { display:block; }

SELECT `call_call`.*, `call_operation`.`id_operation`
FROM `call_call`
LEFT JOIN `call_operation` ON `call_operation`.`id_call_operation` = `call_call`.`id_call`
WHERE `active_call` = '1' AND (`id_operation`>0)
 


Explain:
/** * GeSHi (C) 2004 - 2007 Nigel McNie, 2007 - 2008 Benny Baumann * (http://qbnz.com/highlighter/ and http://geshi.org/) */ .mysql.geshi_code {font-family:monospace;} .mysql.geshi_code .imp {font-weight: bold; color: red;} .mysql.geshi_code .kw1 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw2 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw3 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw4 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw5 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw6 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw7 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw8 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw9 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw10 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw11 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw12 {color: #009900;} .mysql.geshi_code .kw13 {color: #000099;} .mysql.geshi_code .kw14 {color: #000099;} .mysql.geshi_code .kw15 {color: #000099;} .mysql.geshi_code .kw16 {color: #000099;} .mysql.geshi_code .kw17 {color: #000099;} .mysql.geshi_code .kw18 {color: #000099;} .mysql.geshi_code .kw19 {color: #000099;} .mysql.geshi_code .kw20 {color: #000099;} .mysql.geshi_code .kw21 {color: #000099;} .mysql.geshi_code .kw22 {color: #000099;} .mysql.geshi_code .kw23 {color: #000099;} .mysql.geshi_code .kw24 {color: #000099;} .mysql.geshi_code .kw25 {color: #000099;} .mysql.geshi_code .kw26 {color: #000099;} .mysql.geshi_code .kw27 {color: #00CC00;} .mysql.geshi_code .coMULTI {color: #808000; font-style: italic;} .mysql.geshi_code .co1 {color: #808080; font-style: italic;} .mysql.geshi_code .co2 {color: #808080; font-style: italic;} .mysql.geshi_code .es0 {color: #004000; font-weight: bold;} .mysql.geshi_code .es1 {color: #008080; font-weight: bold;} .mysql.geshi_code .br0 {color: #FF00FF;} .mysql.geshi_code .sy1 {color: #CC0099;} .mysql.geshi_code .sy2 {color: #000033;} .mysql.geshi_code .st0 {color: #008000;} .mysql.geshi_code .nu0 {color: #008080;} .mysql.geshi_code span.xtra { display:block; }


id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE call_operation ALL PRIMARY NULL NULL NULL 5717 Using where
1 SIMPLE call_call eq_ref PRIMARY PRIMARY 8 recaller.call_operation.id_call_operation 1 Using where
 

Будет занимать всего лишь 0.0074 сек, извлека около 400 строк.
------
Эксперименты:
/** * GeSHi (C) 2004 - 2007 Nigel McNie, 2007 - 2008 Benny Baumann * (http://qbnz.com/highlighter/ and http://geshi.org/) */ .mysql.geshi_code {font-family:monospace;} .mysql.geshi_code .imp {font-weight: bold; color: red;} .mysql.geshi_code .kw1 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw2 {color: #990099; font-weight: bold;} .mysql.geshi_code .kw3 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw4 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw5 {color: #999900; font-weight: bold;} .mysql.geshi_code .kw6 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw7 {color: #FF9900; font-weight: bold;} .mysql.geshi_code .kw8 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw9 {color: #9900FF; font-weight: bold;} .mysql.geshi_code .kw10 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw11 {color: #CC0099; font-weight: bold;} .mysql.geshi_code .kw12 {color: #009900;} .mysql.geshi_code .kw13 {color: #000099;} .mysql.geshi_code .kw14 {color: #000099;} .mysql.geshi_code .kw15 {color: #000099;} .mysql.geshi_code .kw16 {color: #000099;} .mysql.geshi_code .kw17 {color: #000099;} .mysql.geshi_code .kw18 {color: #000099;} .mysql.geshi_code .kw19 {color: #000099;} .mysql.geshi_code .kw20 {color: #000099;} .mysql.geshi_code .kw21 {color: #000099;} .mysql.geshi_code .kw22 {color: #000099;} .mysql.geshi_code .kw23 {color: #000099;} .mysql.geshi_code .kw24 {color: #000099;} .mysql.geshi_code .kw25 {color: #000099;} .mysql.geshi_code .kw26 {color: #000099;} .mysql.geshi_code .kw27 {color: #00CC00;} .mysql.geshi_code .coMULTI {color: #808000; font-style: italic;} .mysql.geshi_code .co1 {color: #808080; font-style: italic;} .mysql.geshi_code .co2 {color: #808080; font-style: italic;} .mysql.geshi_code .es0 {color: #004000; font-weight: bold;} .mysql.geshi_code .es1 {color: #008080; font-weight: bold;} .mysql.geshi_code .br0 {color: #FF00FF;} .mysql.geshi_code .sy1 {color: #CC0099;} .mysql.geshi_code .sy2 {color: #000033;} .mysql.geshi_code .st0 {color: #008000;} .mysql.geshi_code .nu0 {color: #008080;} .mysql.geshi_code span.xtra { display:block; }

WHERE NOT (`id_operation`>0)        /* возвращает 0 строк */
WHERE (`id_operation`<1)          /* возвращает 0 строк */
WHERE NOT EXIST `id_operation`        /* возвращает error */
WHERE CONVERT(`id_operation`,UNSIGNED) = 0   /* возвращает 0 строк */
WHERE (`id_operation`*1) = 0        /* возвращает 0 строк */
WHERE `id_operation` = NULL          /* возвращает 0 строк */
WHERE `id_operation` NOT REGEXP '^[0-9]+$'  /* возвращает 0 строк */
 

------
Разница в скорости насколько я понимаю вылазит из-за того, что во втором запросе используется поиск по ключу.

Вопрос: как мне преобразовать первый запрос без использования IS NULL? Есть ли какие нибудь аналоги данной конструкции.

Может это как-то можно разрешить через CREATE VIEW? Как-то заменять NULL на какое либо число, скажем -1 ?

Need help, буду рад любому совету.
0
mysql null sql

1 ответов

Разобрался с вопросом мой коллега.
IS NULL никуда не делся, и дело было не в нем, я не туда копал.

Если на поле `id_call_operation` в таблице `call_operation` проставить индекс, то занимаемое время мгновенно падает до 0.0012 сек.

Вопрос закрыт. Всем учавствовавшим спасибо.

1