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或在MySQL中使查询非常慢

[英]OR in MySQL where makes query very slow

 原文  2012-11-16 19:36:59  0   4    mysql/ sql/ magento

问题描述

我在MySQL中有一个关于magento的大查询，这需要很多时间。 我试图对其进行优化，但是我的MySQL知识不足以解决它，因此也许有人可以看看并向我提供一些正确方向的提示。 

Select Distinct
  `e`.*,
  `cat_index`.`position` AS `cat_index_position`,
  `price_index`.`price`,
  `price_index`.`tax_class_id`,
  `price_index`.`final_price`,
  IF(price_index.tier_price IS NOT NULL, 
      LEAST(price_index.min_price, price_index.tier_price),
      price_index.min_price) AS `minimal_price`,
  `price_index`.`min_price`,
  `price_index`.`max_price`,
  `price_index`.`tier_price`
From
  `catalog_product_entity` AS `e`
    Inner Join
  `catalog_category_product_index` As `cat_index`
    On cat_index.product_id=e.entity_id And
       cat_index.store_id=1 And
       cat_index.visibility In(2, 4) And
       cat_index.category_id='2'
    Inner Join
  `catalog_product_index_price` AS `price_index` 
    On price_index.entity_id = e.entity_id And
       price_index.website_id = '1' And
       price_index.customer_group_id = 0
    Left Join
  `beta_entity_product` AS `beta` 
    On e.entity_id = beta.product_id And
       beta.entity_id In (81558, 81559, ... stupidly long list of ids)
    Left Join 
  `catalog_product_entity_int` AS `is_uni` 
    On e.entity_id = is_uni.entity_id And
       attribute_id = 179 
Where 
 is_uni.value = 1 OR 
 beta.product_id IS NOT NULL

如果我在WHERE子句中只有1个条件，那么一切都很好，但是使用OR有时需要几分钟才能完成，那太长了。 我必须选择哪些选项才能获得更好的结果？ 另一个问题是我无法从中进行更多查询，而只能将结果结合在一起。 一切都必须在1个查询中。

当我对查询执行EXPLAIN时，会得到以下结果（以JSON格式复制，以获得更好的概述）： 

{
        "data":
        [
            {
                "id": 1,
                "select_type": "SIMPLE",
                "table": "e",
                "type": "ALL",
                "possible_keys": "PRIMARY",
                "key": null,
                "key_len": null,
                "ref": null,
                "rows": 213396,
                "Extra": "Using temporary"
            },
            {
                "id": 1,
                "select_type": "SIMPLE",
                "table": "beta",
                "type": "range",
                "possible_keys": "PRIMARY",
                "key": "PRIMARY",
                "key_len": "4",
                "ref": null,
                "rows": 2833,
                "Extra": "Using where; Using index"
            },
            {
                "id": 1,
                "select_type": "SIMPLE",
                "table": "is_uni",
                "type": "ref",
                "possible_keys": "UNQ_CATALOG_PRODUCT_ENTITY_INT_ENTITY_ID_ATTRIBUTE_ID_STORE_ID,IDX_CATALOG_PRODUCT_ENTITY_INT_ATTRIBUTE_ID,IDX_CATALOG_PRODUCT_ENTITY_INT_ENTITY_ID",
                "key": "UNQ_CATALOG_PRODUCT_ENTITY_INT_ENTITY_ID_ATTRIBUTE_ID_STORE_ID",
                "key_len": "6",
                "ref": "unc_cpk.e.entity_id,const",
                "rows": 1,
                "Extra": "Using where"
            },
            {
                "id": 1,
                "select_type": "SIMPLE",
                "table": "cat_index",
                "type": "eq_ref",
                "possible_keys": "PRIMARY,IDX_CAT_CTGR_PRD_IDX_PRD_ID_STORE_ID_CTGR_ID_VISIBILITY,15D3C269665C74C2219037D534F4B0DC",
                "key": "PRIMARY",
                "key_len": "10",
                "ref": "const,unc_cpk.e.entity_id,const",
                "rows": 1,
                "Extra": "Using where"
            },
            {
                "id": 1,
                "select_type": "SIMPLE",
                "table": "price_index",
                "type": "eq_ref",
                "possible_keys": "PRIMARY,IDX_CATALOG_PRODUCT_INDEX_PRICE_CUSTOMER_GROUP_ID,IDX_CATALOG_PRODUCT_INDEX_PRICE_WEBSITE_ID",
                "key": "PRIMARY",
                "key_len": "8",
                "ref": "unc_cpk.cat_index.product_id,const,const",
                "rows": 1,
                "Extra": "Using where"
            }
        ]
    }

4 个解决方案

解决方案1
 1  2012-11-16 19:57:42

如果每个具有一个条件的查询都很快，请尝试执行 

Select
  blah
Where
  is_uni.value = 1
Union
Select
  blah
Where
  beta.product_id Is Not Null

只要他们没有返回太多结果，这也将是相当快的。

或者，当您在一个条件下快速说话时，您是说第一个条件吗？

解决方案2
 1  2012-11-16 20:01:13

看起来您需要在beta.product_id上beta.product_id索引，除非这是您的主键？

否则，您可以将其作为并集查询来执行，每个查询都有一个不同的where子句： 

SELECT DISTINCT `e`.*, `cat_index`.`position` AS `cat_index_position`, `price_index`.`price`, 
   `price_index`.`tax_class_id`, `price_index`.`final_price`, IF(price_index.tier_price IS NOT 
   NULL, LEAST(price_index.min_price, price_index.tier_price),
    price_index.min_price) AS `minimal_price`, `price_index`.`min_price`, 
   `price_index`.`max_price`, `price_index`.`tier_price` 
FROM `catalog_product_entity` AS `e`
 INNER JOIN `catalog_category_product_index` AS `cat_index` ON cat_index.product_id=e.entity_id 
      AND cat_index.store_id=1 AND cat_index.visibility IN(2, 4) AND cat_index.category_id='2'
 INNER JOIN `catalog_product_index_price` AS `price_index` ON price_index.entity_id = e.entity_id 
  AND price_index.website_id = '1' AND price_index.customer_group_id = 0
 LEFT JOIN `beta_entity_product` AS `beta` ON e.entity_id = beta.product_id AND beta.entity_id IN (81558,81559,84592,84593,87758,87759,87760,87761,90944,90945,90946,90947,94364,94365,94366,94367,98458,98459,98460,98461,98462,98463,104194,104195,104196,104197,110151,110152,110153,110154,110155,110156,116583,116584,116585,116586,123366,123367,123368,123369,123370,123371,123372,123373,130500,130501,130502,130503,130504,130505,130506,138075,138076,138077,138078,138079,138080,146179,146180,146181,146182,146183,146184,154543,154544,154545,154546,154547,154548,154549,154550,163639,163640,163641,163642,163643,163644,163645,173998,173999,174000,174001,174002,174003,174004,174005,174006,174007,184545,184546,184547,184548,184549,184550,195249,195250,195251,195252,195253,195254,195255,195256,195257,195258,206400,206401,206402,206403,206404,206405,217632,217633,217634,217635,217636,217637,217638,217639,229029,229030,229031,229032,229033,229034,229035,229036,229037,229038,229039,229040,240350,240351,240352,240353,240354,240355,240356,240357,240358,240359,240360,240361,251631,251632,251633,251634,251635,251636,251637,251638,251639,262900,262901,262902,262903,262904,262905,262906,262907,262908,262909,274205,274206,274207,274208,274209,274210,274211,274212,274213,274214,274215,274216,274217,285747,285748,285749,285750,285751,285752,285753,285754,285755,285756,285757,285758,297747,297748,297749,297750,297751,297752,297753,297754,297755,297756,297757,297758,297759,297760,297761,309660,309661,309662,309663,309664,309665,309666,309667,322314,322315,322316,322317,322318,322319,322320,322321,334814,334815,334816,334817,334818,334819,334820,334821,334822,334823,334824,334825,334826,346810,346811,346812,346813,346814,346815,346816,346817,346818,346819,346820,346821,358550,358551,358552,358553,358554,358555,358556,358557,358558,358559,358560,358561,358562,370376,370377,370378,370379,370380,370381,370382,370383,370384,370385,370386,370387,381938,381939,381940,381941,381942,381943,381944,381945,381946,381947,381948,381949,381950,391081,391082,391083,391084,391085,391086,391087,391088,391089,391090,391091,391092,391093,396111,396112,396113,396114,396115,396116,396117,396118,396119,396120,396121,396122,396123,396124,396125)
 LEFT JOIN `catalog_product_entity_int` AS `is_uni` ON e.entity_id = is_uni.entity_id AND attribute_id = 179 


WHERE is_uni.value = 1 
UNION
SELECT DISTINCT `e`.*, `cat_index`.`position` AS `cat_index_position`, `price_index`.`price`, 
   `price_index`.`tax_class_id`, `price_index`.`final_price`, IF(price_index.tier_price IS NOT 
   NULL, LEAST(price_index.min_price, price_index.tier_price),
    price_index.min_price) AS `minimal_price`, `price_index`.`min_price`, 
   `price_index`.`max_price`, `price_index`.`tier_price` 
FROM `catalog_product_entity` AS `e`
 INNER JOIN `catalog_category_product_index` AS `cat_index` ON cat_index.product_id=e.entity_id 
      AND cat_index.store_id=1 AND cat_index.visibility IN(2, 4) AND cat_index.category_id='2'
 INNER JOIN `catalog_product_index_price` AS `price_index` ON price_index.entity_id = e.entity_id 
  AND price_index.website_id = '1' AND price_index.customer_group_id = 0
 LEFT JOIN `beta_entity_product` AS `beta` ON e.entity_id = beta.product_id AND beta.entity_id IN (81558,81559,84592,84593,87758,87759,87760,87761,90944,90945,90946,90947,94364,94365,94366,94367,98458,98459,98460,98461,98462,98463,104194,104195,104196,104197,110151,110152,110153,110154,110155,110156,116583,116584,116585,116586,123366,123367,123368,123369,123370,123371,123372,123373,130500,130501,130502,130503,130504,130505,130506,138075,138076,138077,138078,138079,138080,146179,146180,146181,146182,146183,146184,154543,154544,154545,154546,154547,154548,154549,154550,163639,163640,163641,163642,163643,163644,163645,173998,173999,174000,174001,174002,174003,174004,174005,174006,174007,184545,184546,184547,184548,184549,184550,195249,195250,195251,195252,195253,195254,195255,195256,195257,195258,206400,206401,206402,206403,206404,206405,217632,217633,217634,217635,217636,217637,217638,217639,229029,229030,229031,229032,229033,229034,229035,229036,229037,229038,229039,229040,240350,240351,240352,240353,240354,240355,240356,240357,240358,240359,240360,240361,251631,251632,251633,251634,251635,251636,251637,251638,251639,262900,262901,262902,262903,262904,262905,262906,262907,262908,262909,274205,274206,274207,274208,274209,274210,274211,274212,274213,274214,274215,274216,274217,285747,285748,285749,285750,285751,285752,285753,285754,285755,285756,285757,285758,297747,297748,297749,297750,297751,297752,297753,297754,297755,297756,297757,297758,297759,297760,297761,309660,309661,309662,309663,309664,309665,309666,309667,322314,322315,322316,322317,322318,322319,322320,322321,334814,334815,334816,334817,334818,334819,334820,334821,334822,334823,334824,334825,334826,346810,346811,346812,346813,346814,346815,346816,346817,346818,346819,346820,346821,358550,358551,358552,358553,358554,358555,358556,358557,358558,358559,358560,358561,358562,370376,370377,370378,370379,370380,370381,370382,370383,370384,370385,370386,370387,381938,381939,381940,381941,381942,381943,381944,381945,381946,381947,381948,381949,381950,391081,391082,391083,391084,391085,391086,391087,391088,391089,391090,391091,391092,391093,396111,396112,396113,396114,396115,396116,396117,396118,396119,396120,396121,396122,396123,396124,396125)
 LEFT JOIN `catalog_product_entity_int` AS `is_uni` ON e.entity_id = is_uni.entity_id AND attribute_id = 179
WHERE beta.product_id IS NOT NULL

根据您的数据，如果OR是互斥数据，则可以使用UNION ALL。 您正在运行的查询不能完全利用INDEX MERGE，而使用OR语句使其快速运行将需要它。

解决方案3
 1 已采纳  2012-11-16 20:34:39

有多种解决方案：

1）拆分查询并使用UNION-可能存在排序和分页问题2）添加仅将用于此过滤器的新属性，而不是

is_uni.value = 1或beta.product_id不为空

你只会查询

feature_filter = 1

3）将查询分解为多个查询-我建议您将其作为第一步，因为与该查询一样大的查询确实是击掌的好方法

顺便说一句。 对这么多列使用不重复查询会消耗大量资源（mysql需要比较每个列的值！）

解决方案4
 0  2012-11-16 20:14:11

意见建议：

1.）代替 

beta.product_id IS NOT NULL

写 

not (beta.product_id IS NULL)

2）如果您需要一个查询请求，则可以创建一个存储过程或一个存储函数。 当然，您可以使用多个查询，最后使用单个数据库服务器请求合并部分结果。

3.）如果您具有复杂的数据库逻辑，请使用ORM ，例如Flourish 。

祝你好运。

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