mysql查询在一段时间不活动后超时-我认为是查询缓存问题

Question

使用最新的 mysql 服务器，

一段时间不活动后，我的网站 sqls 超时(只有一些不是全部)这些查询不是新编写的现有查询。

测试结果

1. 当执行像(从产品中选择计数(*))这样的简单 sql 时，它一直工作正常。

2. 执行下面的sql时

   SELECT products.pid
   FROM
       products INNER JOIN
       catalog ON products.cid=catalog.cid
   WHERE
       products.is_visible = 'Yes' AND (
           products.inventory_control = 'No' OR
           products.stock > 0 OR
           products.inventory_rule = 'OutOfStock' OR (
               products.inventory_control = 'AttrRuleInc' AND
               products.stock >= 0
           )
       ) AND products.is_home = 'Yes'
   GROUP BY products.pid
   

它超时(注意它不会一直超时，这会在 1 小时或 2 小时不活动后发生)

1. 第一次执行需要 30 多秒，然后超时，然后上面执行 SQL 2 到 3 次，第 4 次开始，它在 3 到 5 秒内快速执行

在 1 或 2 小时不活动后，此模式会重复。

我没有对设置进行任何更改。

我在此服务器上有 2 个站点。

第一个服务器在数据库中有 20,000 行(这个工作正常)第二个站点在数据库中有 150,000 行(这个有这个问题)

所以这是“查询超时”

我不认为这是 SQL 设置的问题，如果是的话我应该会在两个站点上看到这种行为

**** 这里是表结构，超时/耗时 40 秒

#this structure has 2 additional keys we created 
#  KEY `product_id` (`product_id`),
#  KEY `product_no` (`product_no`)

# this one is having issues


--
-- Table structure for table `products` on lpbatt database server
--

DROP TABLE IF EXISTS `products`;
SET @saved_cs_client     = @@character_set_client;
SET character_set_client = utf8;
CREATE TABLE `products` (
  `pid` int(10) unsigned NOT NULL auto_increment,
  `cid` int(10) unsigned NOT NULL default '0',
  `manufacturer_id` int(10) unsigned NOT NULL default '0',
  `is_visible` enum('Yes','No') NOT NULL default 'Yes',
  `is_hotdeal` enum('Yes','No') NOT NULL default 'No',
  `is_home` enum('Yes','No') NOT NULL default 'No',
  `is_taxable` enum('Yes','No') NOT NULL default 'Yes',
  `is_dollar_days` enum('Yes','No') NOT NULL default 'No',
  `is_google_co` enum('Yes','No') NOT NULL default 'Yes',
  `is_doba` enum('Yes','No') NOT NULL default 'No',
  `is_locked` enum('Yes','No') NOT NULL default 'No',
  `inventory_control` enum('Yes','AttrRuleExc','AttrRuleInc','No') NOT NULL default 'No',
  `inventory_rule` enum('Hide','OutOfStock') NOT NULL default 'Hide',
  `stock` int(10) NOT NULL default '0',
  `stock_warning` int(10) NOT NULL default '0',
  `weight` decimal(10,2) unsigned NOT NULL default '0.00',
  `free_shipping` enum('Yes','No') NOT NULL default 'No',
  `digital_product` enum('Yes','No') NOT NULL default 'No',
  `digital_product_file` varchar(255) NOT NULL default '',
  `cost` decimal(20,5) unsigned NOT NULL default '0.00000',
  `price` decimal(20,5) unsigned NOT NULL default '0.00000',
  `price2` decimal(20,5) unsigned NOT NULL default '0.00000',
  `price_level_1` decimal(20,5) unsigned NOT NULL default '0.00000',
  `price_level_2` decimal(20,5) unsigned NOT NULL default '0.00000',
  `price_level_3` decimal(20,5) unsigned NOT NULL default '0.00000',
  `shipping_price` decimal(20,5) unsigned NOT NULL default '0.00000',
  `tax_class_id` int(10) unsigned NOT NULL default '0',
  `tax_rate` decimal(20,5) NOT NULL default '-1.00000',
  `call_for_price` enum('Yes','No') NOT NULL default 'No',
  `priority` int(11) NOT NULL default '0',
  `attributes_count` int(11) NOT NULL default '0',
  `min_order` int(10) NOT NULL default '1',
  `max_order` int(10) unsigned NOT NULL default '0',
  `added` datetime NOT NULL default '0000-00-00 00:00:00',
  `products_location_id` int(10) unsigned NOT NULL default '0',
 `url_hash` varchar(32) NOT NULL default '',
  `url_default` varchar(128) NOT NULL default '',
  `url_custom` varchar(128) NOT NULL default '',
  `product_id` int(64) NOT NULL default '0',
  `product_sku` varchar(64) NOT NULL default '',
  `product_upc` varchar(64) NOT NULL default '',
  `case_pack` int(11) NOT NULL default '-1',
  `inter_pack` int(11) NOT NULL default '-1',
  `gift_quantity` int(10) unsigned NOT NULL default '0',
  `dimension_width` decimal(10,2) NOT NULL default '0.00',
  `dimension_length` decimal(10,2) NOT NULL default '0.00',
  `dimension_height` decimal(10,2) NOT NULL default '0.00',
  `image_location` enum('Local','Web') NOT NULL default 'Local',
  `image_url` varchar(255) NOT NULL default '',
  `image_alt_text` varchar(255) NOT NULL default '',
  `tmp_manufacturer` varchar(30) default NULL,
  `tmp_family` varchar(30) default NULL,
  `tmp_series` varchar(30) default NULL,
  `tmp_model` varchar(30) default NULL,
  `tmp_ptype` varchar(30) default NULL,
  `product_no` varchar(40) default NULL,
  `part_no` varchar(300) default NULL,
  `spec_1` varchar(7) default NULL,
  `spec_2` varchar(7) default NULL,
  `spec_3` varchar(7) default NULL,
  `spec_4` varchar(40) default NULL,
  `title` varchar(255) NOT NULL default '',
  `meta_keywords` text NOT NULL,
  `meta_title` text NOT NULL,
  `meta_description` text NOT NULL,
  `overview` text,
  `description` text,
  `zoom_option` enum('global','none','zoom','magnify','magicthumb','imagelayover') NOT NULL default 'global',
  PRIMARY KEY  (`pid`),
  KEY `cid` (`cid`),
  KEY `is_visible` (`is_visible`),
  KEY `url_hash` (`url_hash`),
  KEY `product_id` (`product_id`),
  KEY `product_no` (`product_no`)
) ENGINE=MyISAM AUTO_INCREMENT=1630746530 DEFAULT CHARSET=utf8;
SET character_set_client = @saved_cs_client;

---

下面是在另一台服务器上运行但工作正常的表结构

#see the products table structure and catalog table structure 
#this is fine on this server 


# --------------------------------------------------------
# Host:                         laptopnbparts.com
# Database:                     laptopnbpartscom
# Server version:               5.0.77
# Server OS:                    redhat-linux-gnu
# HeidiSQL version:             5.0.0.3222
# Date/time:                    2010-06-25 18:13:33
# --------------------------------------------------------

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET NAMES utf8 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;

# Dumping structure for table laptopnbpartscom.catalog
CREATE TABLE IF NOT EXISTS `catalog` (
  `cid` int(10) unsigned NOT NULL auto_increment,
  `parent` int(10) unsigned NOT NULL default '0',
  `level` int(10) unsigned NOT NULL default '0',
  `priority` smallint(5) unsigned NOT NULL default '5',
  `is_visible` enum('Yes','No') NOT NULL default 'Yes',
  `list_subcats` enum('Yes','No') NOT NULL default 'No',
  `url_hash` varchar(32) NOT NULL default '',
  `url_default` varchar(128) NOT NULL default '',
  `url_custom` varchar(128) NOT NULL default '',
  `key_name` varchar(255) NOT NULL default '',
  `meta_keywords` text,
  `meta_title` text,
  `meta_description` text,
  `category_header` varchar(255) NOT NULL default '',
  `name` varchar(255) NOT NULL default '',
  `description` text,
  `description_bottom` text,
  `category_path` text,
  PRIMARY KEY  (`cid`),
  KEY `parent` (`parent`),
  KEY `level` (`level`),
  KEY `priority` (`priority`),
  KEY `url_hash` (`url_hash`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

# Data exporting was unselected.


# Dumping structure for table laptopnbpartscom.products
CREATE TABLE IF NOT EXISTS `products` (
  `pid` int(10) unsigned NOT NULL auto_increment,
  `cid` int(10) unsigned NOT NULL default '0',
  `manufacturer_id` int(10) unsigned NOT NULL default '0',
  `is_visible` enum('Yes','No') NOT NULL default 'Yes',
  `is_hotdeal` enum('Yes','No') NOT NULL default 'No',
  `is_home` enum('Yes','No') NOT NULL default 'No',
  `is_taxable` enum('Yes','No') NOT NULL default 'Yes',
  `is_dollar_days` enum('Yes','No') NOT NULL default 'No',
  `is_google_co` enum('Yes','No') NOT NULL default 'Yes',
  `is_doba` enum('Yes','No') NOT NULL default 'No',
  `is_locked` enum('Yes','No') NOT NULL default 'No',
  `inventory_control` enum('Yes','AttrRuleExc','AttrRuleInc','No') NOT NULL default 'No',
  `inventory_rule` enum('Hide','OutOfStock') NOT NULL default 'Hide',
  `stock` int(10) NOT NULL default '0',
  `stock_warning` int(10) NOT NULL default '0',
  `weight` decimal(10,2) unsigned NOT NULL default '0.00',
  `free_shipping` enum('Yes','No') NOT NULL default 'No',
  `digital_product` enum('Yes','No') NOT NULL default 'No',
  `digital_product_file` varchar(255) NOT NULL default '',
  `cost` decimal(20,5) unsigned NOT NULL default '0.00000',
  `price` decimal(20,5) unsigned NOT NULL default '0.00000',
  `price2` decimal(20,5) unsigned NOT NULL default '0.00000',
  `price_level_1` decimal(20,5) unsigned NOT NULL default '0.00000',
  `price_level_2` decimal(20,5) unsigned NOT NULL default '0.00000',
  `price_level_3` decimal(20,5) unsigned NOT NULL default '0.00000',
  `shipping_price` decimal(20,5) unsigned NOT NULL default '0.00000',
  `tax_class_id` int(10) unsigned NOT NULL default '0',
  `tax_rate` decimal(20,5) NOT NULL default '-1.00000',
  `call_for_price` enum('Yes','No') NOT NULL default 'No',
  `priority` int(11) NOT NULL default '0',
  `attributes_count` int(11) NOT NULL default '0',
  `min_order` int(10) NOT NULL default '1',
  `max_order` int(10) unsigned NOT NULL default '0',
  `added` datetime NOT NULL default '0000-00-00 00:00:00',
  `products_location_id` int(10) unsigned NOT NULL default '0',
  `url_hash` varchar(32) NOT NULL default '',
  `url_default` varchar(128) NOT NULL default '',
  `url_custom` varchar(128) NOT NULL default '',
  `product_id` varchar(64) NOT NULL default '',
  `product_sku` varchar(64) NOT NULL default '',
  `product_upc` varchar(64) NOT NULL default '',
  `case_pack` int(11) NOT NULL default '-1',
  `inter_pack` int(11) NOT NULL default '-1',
  `gift_quantity` int(10) unsigned NOT NULL default '0',
  `dimension_width` decimal(10,2) NOT NULL default '0.00',
  `dimension_length` decimal(10,2) NOT NULL default '0.00',
  `dimension_height` decimal(10,2) NOT NULL default '0.00',
  `image_location` enum('Local','Web') NOT NULL default 'Local',
  `image_url` varchar(255) NOT NULL default '',
  `image_alt_text` varchar(255) NOT NULL default '',
  `tmp_manufacturer` varchar(30) default NULL,
  `tmp_series` varchar(30) default NULL,
  `tmp_model` varchar(30) default NULL,
  `tmp_ptype` varchar(30) default NULL,
  `product_no` varchar(60) default NULL,
  `part_no` varchar(60) default NULL,
  `watt_volt_amp` varchar(100) default NULL,
  `title` varchar(255) NOT NULL default '',
  `meta_keywords` text NOT NULL,
  `meta_title` text NOT NULL,
  `meta_description` text NOT NULL,
  `overview` text,
  `description` text,
  `zoom_option` enum('global','none','zoom','magnify','magicthumb','imagelayover') NOT NULL default 'global',
  PRIMARY KEY  (`pid`),
  KEY `cid` (`cid`),
  KEY `is_visible` (`is_visible`),
  KEY `url_hash` (`url_hash`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

# Data exporting was unselected.
/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;

Answer 1

尝试在 WHERE 子句中使用 CASE WHEN 而不是多个 OR 语句，并在客户端进行评估。OR 是众所周知的性能 killer ，因为 MySQL 通常不能应用索引，并且必须检查每条语句以过滤掉行。