Question

在Mysql 5.6上，如果我每分钟运行一次以下查询：

SELECT 
    Count(DISTINCT oxv_oxarticles_de.`oxid`) 
FROM
    oxobject2category 
INNER JOIN 
    oxv_oxarticles_de ON oxobject2category.`oxobjectid` = oxv_oxarticles_de.`oxid` 
                      AND oxv_oxarticles_de.`oxparentid` = '' 
WHERE  
    oxobject2category.`oxcatnid` = 'XXXXXXXXXXXXXXXXX' 
    AND (oxv_oxarticles_de.oxactive = 1 
         AND (oxv_oxarticles_de.oxstockflag != 2 
              OR (oxv_oxarticles_de.oxstock 
                     + oxv_oxarticles_de.oxvarstock) > 0) 
         AND IF(oxv_oxarticles_de.oxvarcount = 0, 1, (SELECT 1 
                                                      FROM 
             oxv_oxarticles_de AS art 
                                                      WHERE 
                 art.oxparentid = oxv_oxarticles_de.oxid 
                 AND ( art.oxactive = 1 ) 
                 AND ( art.oxstockflag != 2 
                        OR art.oxstock > 0 ) 
                                                      LIMIT  1)) )

该网站将每3天停止回复一次。

+----+--------------------+-------------------+--------+-------------------------------------------------+-----------+---------+----------------------------------------------+------+------------------------------------+
| id | select_type        | table             | type   | possible_keys                                   | key       | key_len | ref                                          | rows | Extra                              |
+----+--------------------+-------------------+--------+-------------------------------------------------+-----------+---------+----------------------------------------------+------+------------------------------------+
|  1 | PRIMARY            | oxobject2category | ref    | OXMAINIDX,OXOBJECTID                            | OXMAINIDX | 32      | const                                        |   33 | Using where; Using index           |
|  1 | PRIMARY            | oxarticles        | eq_ref | PRIMARY,OXCOUNT,OXSTOCKFLAG,OXACTIVE,parentsort | PRIMARY   | 32      | oxid_erima_prod.oxobject2category.OXOBJECTID |    1 | Using where                        |
|  2 | DEPENDENT SUBQUERY | oxarticles        | ref    | OXCOUNT,OXSTOCK,OXSTOCKFLAG,OXACTIVE,parentsort | OXCOUNT   | 32      | func                                         |    5 | Using index condition; Using where |
+----+--------------------+-------------------+--------+-------------------------------------------------+-----------+---------+----------------------------------------------+------+------------------------------------+
3 rows in set (0.00 sec)

报告的错误是

mysql error: [5: Out of memory (Needed 1048544 bytes)] in EXECUTE (SELECT COUNT( DISTINCT...

这个问题并不是如何“稍微优化”一下这个问题 - 尽管我对这些提示表示感谢。我需要帮助才能找到可能会导致严重破坏的查询的臭部分。通常（约99.9％）的执行时间不到1毫秒，执行时间为2微秒。

提前致谢！

Answer 1

SHOW VARIABLES LIKE '%size';

您可能会找到一个1048544或接近1048544的值。提高该值。

然后问为什么您需要计算不同氧化物的数量。

查询运行多长时间？如果要花费一分钟以上的时间，请不要每分钟运行一次。相反，让我们对其进行优化。为此，请为相关表格提供SHOW CREATE TABLE。

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1 个答案: