EAV结构化数据复杂搜索需要MySQL优化

Question

我有一个包含EAV结构化数据的大型数据库，必须具有可搜索性和可分页性。我尝试了我书中的每一个技巧，以使它足够快，但在某些情况下，它仍然未能在合理的时间内完成。

这是我的桌子结构(只有相关的部分，如果你需要更多的话，可以问一下)：

CREATE TABLE IF NOT EXISTS `object` (
  `object_id` bigint(20) NOT NULL AUTO_INCREMENT,
  `oid` varchar(32) CHARACTER SET utf8 NOT NULL,
  `status` varchar(100) CHARACTER SET utf8 DEFAULT NULL,
  `created` datetime NOT NULL,
  `updated` datetime NOT NULL,
  PRIMARY KEY (`object_id`),
  UNIQUE KEY `oid` (`oid`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8;

CREATE TABLE IF NOT EXISTS `version` (
  `version_id` bigint(20) NOT NULL AUTO_INCREMENT,
  `type_id` bigint(20) NOT NULL,
  `object_id` bigint(20) NOT NULL,
  `created` datetime NOT NULL,
  `status` varchar(100) CHARACTER SET utf8 DEFAULT NULL,
  PRIMARY KEY (`version_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8;

CREATE TABLE IF NOT EXISTS `value` (
  `value_id` bigint(20) NOT NULL AUTO_INCREMENT,
  `object_id` int(11) NOT NULL,
  `attribute_id` int(11) NOT NULL,
  `version_id` bigint(20) NOT NULL,
  `type_id` bigint(20) NOT NULL,
  `value` text NOT NULL,
  PRIMARY KEY (`value_id`),
  KEY `field_id` (`attribute_id`),
  KEY `action_id` (`version_id`),
  KEY `form_id` (`type_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8;

这是一个示例对象。我的数据库中大约有100万。每个对象可能有不同数量的属性，具有不同的attribute_id。

INSERT INTO `owner` (`owner_id`, `uid`, `status`, `created`, `updated`) VALUES (1, 'cwnzrdxs4dzxns47xs4tx', 'Green', NOW(), NOW());
INSERT INTO `object` (`object_id`, `type_id`, `owner_id`, `created`, `status`) VALUES (1, 1, 1, NOW(), NOW());
INSERT INTO `value` (`value_id`, `owner_id`, `attribute_id`, `object_id`, `type_id`, `value`) VALUES (1, 1, 1, 1, 1, 'Munich');
INSERT INTO `value` (`value_id`, `owner_id`, `attribute_id`, `object_id`, `type_id`, `value`) VALUES (2, 1, 2, 1, 1, 'Germany');
INSERT INTO `value` (`value_id`, `owner_id`, `attribute_id`, `object_id`, `type_id`, `value`) VALUES (3, 1, 3, 1, 1, '123');
INSERT INTO `value` (`value_id`, `owner_id`, `attribute_id`, `object_id`, `type_id`, `value`) VALUES (4, 1, 4, 1, 1, '2012-01-13');
INSERT INTO `value` (`value_id`, `owner_id`, `attribute_id`, `object_id`, `type_id`, `value`) VALUES (5, 1, 5, 1, 1, 'A cake!');

现在谈我目前的机制。我的第一次尝试是Mysql的典型方法。在我需要的任何东西上执行一个包含大量连接的大型SQL。完完全全的独裁者！由于内存耗尽，加载时间太长，甚至导致PHP和MySQL服务器崩溃。

因此，我将我的查询分成几个步骤：

1确定所有需要的attribute_ids.

我可以在引用对象的type_id的另一个表中查找它们。结果是一个attribute_ids列表。(此表与性能不太相关，因此不在我的示例中。)

:type_id包含来自我想要包含在搜索中的任何对象的所有type_ids。我已经在我的申请中得到了这个信息。所以这个很便宜。

SELECT * FROM attribute WHERE form_id IN (:type_id)

结果是一个type_id整数数组。

2搜索匹配对象编译了一个大型查询，它为我想要的每个条件添加一个内部联接。这听起来很可怕，但最后，它是最快的方法：

典型的生成查询可能如下所示。可悲的是，限制是必要的，否则我可能会得到太多的I，导致PHP在下一个查询中爆炸或中断IN语句：

SELECT DISTINCT `version`.object_id FROM `version`
INNER JOIN `version` AS condition1 
        ON `version`.version_id = condition1.version_id 
       AND condition1.created = '2012-03-04' -- Filter by version date
INNER JOIN `value` AS condition2 
        ON `version`.version_id = condition2.version_id
       AND condition2.type_id IN (:type_id) -- try to limit joins to object types we need
       AND condition2.attribute_id = :field_id2 -- searching for a value in a specific attribute
       AND condition2.value = 'Munich' -- searching for the value 'Munich'
INNER JOIN `value` AS condition3 
        ON `version`.version_id = condition3.version_id
       AND condition3.type_id IN (:type_id) -- try to limit joins to object types we need
       AND condition3.attribute_id = :field_id3 -- searching for a value in a specific attribute
       AND condition3.value = 'Green' -- searching for the value 'Green'
WHERE `version`.type_id IN (:type_id) ORDER BY `version`.version_id DESC LIMIT 10000

结果将包含来自我可能需要的任何对象的所有object_ids。我选择的是object_ids，而不是version_ids，因为我需要匹配对象的所有版本，而不管哪个版本匹配。

3排序和页面结果下一步，我将创建一个查询，该查询将按某个属性对对象进行排序，然后分页生成数组。

SELECT DISTINCT object_id
FROM value
WHERE object_id IN (:foundObjects)
AND attribute_id = :attribute_id_to_sort
AND value > ''
ORDER BY value ASC LIMIT :limit OFFSET :offset

结果是前一次搜索中的对象ids的排序和分页列表。

4在最后一步中获取完整的对象、版本和属性，我将为任何对象和以前的查询找到的版本选择所有值。

SELECT `value`.*, `object`.*, `version`.*, `type`.*
`object`.status AS `object.status`,
`object`.flag AS `object.flag`,
`version`.created AS `version.created`,
`version`.status AS `version.status`,
FROM version
INNER JOIN `type` ON `version`.form_id = `type`.type_id
INNER JOIN `object` ON `version`.object_id = `object`.object_id
LEFT JOIN value ON `version`.version_id = `value`.version_id
WHERE version.object_id IN (:sortedObjectIds) AND `version.type_id IN (:typeIds)
ORDER BY version.created DESC

然后通过PHP将结果编译成尼斯对象->version->值数组结构。

现在是问题

• 这样的混乱还能以任何方式加速吗？
• 我是否可以从我的搜索查询中删除限制10000的限制？

如果所有这些都失败了，也许可以切换数据库技术？见我的另一个问题：Database optimized for searching in large number of objects with different attributes

真实生活样本

表大小:对象- 193801行，版本- 193841行，值- 1053928行

SELECT * FROM attribute WHERE attribute_id IN (30)

SELECT DISTINCT `version`.object_id
FROM version  
INNER JOIN value AS condition_d4e328e33813 
     ON version.version_id = condition_d4e328e33813.version_id
    AND condition_d4e328e33813.type_id IN (30)
    AND condition_d4e328e33813.attribute_id IN (377) 
    AND condition_d4e328e33813.value LIKE '%e%'  
INNER JOIN value AS condition_2c870b0a429f 
     ON version.version_id = condition_2c870b0a429f.version_id
    AND condition_2c870b0a429f.type_id IN (30)
    AND condition_2c870b0a429f.attribute_id IN (376) 
    AND condition_2c870b0a429f.value LIKE '%s%' 
WHERE version.type_id IN (30) 
ORDER BY version.version_id DESC LIMIT 10000 -- limit to 10000 or it breaks!

解释：

id  select_type  table                   type      possible_keys                key         key_len ref                               rows      Extra   
1   SIMPLE       condition_2c870b0a429f  ref       field_id,action_id,form_id   field_id    4       const                             178639    Using where; Using temporary; Using filesort
1   SIMPLE       action                  eq_ref    PRIMARY                      PRIMARY     8       condition_2c870b0a429f.action_id  1         Using where
1   SIMPLE       condition_d4e328e33813  ref       field_id,action_id,form_id   action_id   8       action.action_id                  11        Using where; Distinct

完成对象搜索(峰值RAM: 5.91MB，时间: 4.64s)

SELECT DISTINCT object_id
FROM version
WHERE object_id IN (193793,193789, ... ,135326,135324) -- 10000 ids in here!
ORDER BY created ASC
LIMIT 50 OFFSET 0                                                  

完成对象排序(峰值RAM: 6.68MB，时间: 0.352s)

SELECT `value`.*, object.*, version.*, type.*,
    object.status AS `object.status`,
    object.flag AS `object.flag`,
    version.created AS `version.created`,
    version.status AS `version.status`,
    version.flag AS `version.flag`
FROM version
INNER JOIN type ON version.type_id = type.type_id
INNER JOIN object ON version.object_id = object.object_id
LEFT JOIN value ON version.version_id = `value`.version_id
WHERE version.object_id IN (135324,135326,...,135658,135661) AND version.type_id IN (30)
ORDER BY quality DESC, version.created DESC 

完成对象加载查询(峰值RAM: 6.68MB，时间: 0.083s)

将对象编译成已完成的数组(峰值RAM: 6.68MB，时间: 0.007s)

Answer 1

只需在搜索查询之前添加一个解释：

EXPLAIN SELECT DISTINCT `version`.object_id FROM `version`, etc ...

然后检查“额外”列中的结果，它将为您提供一些加快查询速度的线索，例如在正确的字段中添加索引。

还有一些时候，您可以加入removeINNER，在您的Mysql中获得更多的结果，并通过使用PHP循环进行处理来过滤大数组。