我还在研究mysql性能，目前我开始检查mysql服务器上的-log-slow-query命令。
它会返回下一个结果：
/ usr / sbin / mysqld，版本：5.0.81-community-log（MySQL社区版（GPL））。从以下开始：
Tcp port: 0 Unix socket: (null)
Time Id Command Argument
110211 0:28:16 1 Connect promls_sysdba@localhost on
1 Query SET NAMES utf8
1 Init DB promls_box
1 Query select id , fullname from users where company_id = 7
1 Query SELECT FOUND_ROWS() AS total_results
1 Query select id , name from groups where company_id = 7 and context = "agency"
1 Query SELECT FOUND_ROWS() AS total_results
110211 0:28:26 1 Query SET NAMES utf8
1 Init DB promls_box
1 Query SELECT SQL_CALC_FOUND_ROWS property_id, property_type,property_name, bathrooms, bedrooms, for_sale, for_rent, for_vacational, units,
city,estate,country, rent_price, sale_price, min_price,mid_price, hig_price, max_sale,min_sale, min_rent, max_rent, min_vrental,max_vrental,
negotiation,property_status,
category_es category, image, dev_logo, inventory,company_id,broker_id FROM property_listing where property_status in('active','active-rented','active-sold') group by parent order by min_price asc, mid_price asc, hig_price asc, rent_price asc, sale_price asc limit 10, 10
1 Query SELECT FOUND_ROWS() AS total_results
1 Query SET NAMES utf8
1 Init DB promls_box
1 Query select st.id estate_id,st.description estate from active_locations group by estate_id
1 Query SELECT FOUND_ROWS() AS total_results
1 Query select city_id , city from active_locations where estate_id =272 group by city_id
1 Query SELECT FOUND_ROWS() AS total_results
1 Query SET NAMES utf8
1 Init DB promls_box
1 Query select f.id, f.name_es as name from families f inner join category_types ct on ct.category = f.id where type='category' group by f.id
1 Query SELECT FOUND_ROWS() AS total_results
1 Query select t.id, t.name_es as name from property_types t inner join category_types ct on ct.property_type = t.id where ct.category =12
1 Query SELECT FOUND_ROWS() AS total_results
110211 0:28:56 2 Connect root@localhost on
2 Query select id_area , description from areas where parent_area = 2
2 Quit
110211 0:28:58 1 Quit
110211 0:29:01 3 Connect promls_sysdba@localhost on
3 Query SET NAMES utf8
3 Init DB promls_box
3 Query select id , fullname from users where company_id = 7
3 Query SELECT FOUND_ROWS() AS total_results
3 Query select id , name from groups where company_id = 7 and context = "agency"
3 Query SELECT FOUND_ROWS() AS total_results
110211 0:29:43 4 Connect viva_webjun@localhost on
4 Init DB viva_blogen
4 Query SET NAMES utf8
4 Query select name, val from txp_prefs where prefs_id=1 AND user_name=''
4 Query select name, data from txp_lang where lang='en-gb' AND ( event='public' OR event='common')
4 Query select name, code, version from txp_plugin where status = 1 AND type IN (0,1) order by load_order
4 Query select page, css from txp_section where name = 'default' limit 1
4 Query select unix_timestamp(val) from txp_prefs where `name` = 'lastmod' limit 1
4 Query select name from txp_section where in_rss != '1'
4 Query select *, unix_timestamp(Posted) as uPosted, unix_timestamp(LastMod) as uLastMod, unix_timestamp(Expires) as uExpires, ID as thisid from textpattern where Status = 4 and Section != 'about' and Posted < now() and (now() <= Expires or Expires = '0000-00-00 00:00:00') order by Posted desc limit 5
4 Query select RealName from txp_users where `name` = 'webjunkie01' limit 1
4 Query select unix_timestamp(Posted) from textpattern where Posted <= now() and Status >= 4 order by Posted desc limit 1
4 Quit
110211 0:29:44 5 Connect viva_webjun@localhost on
5 Init DB viva_blogen
5 Query SET NAMES utf8
5 Query select name, val from txp_prefs where prefs_id=1 AND user_name=''
5 Query select name, data from txp_lang where lang='en-gb' AND ( event='public' OR event='common')
5 Query select name, code, version from txp_plugin where status = 1 AND type IN (0,1) order by load_order
5 Query select page, css from txp_section where name = 'default' limit 1
5 Query select unix_timestamp(val) from txp_prefs where `name` = 'lastmod' limit 1
5 Query select name from txp_section where in_rss != '1'
5 Query select *, unix_timestamp(Posted) as uPosted, unix_timestamp(LastMod) as uLastMod, unix_timestamp(Expires) as uExpires, ID as thisid from textpattern where Status = 4 and Section != 'about' and Posted < now() and (now() <= Expires or Expires = '0000-00-00 00:00:00') order by Posted desc limit 5
5 Query select RealName from txp_users where `name` = 'webjunkie01' limit 1
5 Query select unix_timestamp(Posted) from textpattern where Posted <= now() and Status >= 4 order by Posted desc limit 1
5 Quit
110211 0:30:02 6 Connect root@localhost on
6 Query show processlist
6 Quit
110211 0:32:28 3 Quit
7 Connect promls_sysdba@localhost on
7 Query SET NAMES utf8
7 Init DB promls_box
7 Query select id , fullname from users where company_id = 7
7 Query SELECT FOUND_ROWS() AS total_results
7 Query select id , name from groups where company_id = 7 and context = "agency"
7 Query SELECT FOUND_ROWS() AS total_results
110211 0:33:02 7 Query SET NAMES utf8
7 Init DB promls_box
7 Query SET NAMES utf8
7 Init DB promls_box
7 Query SET NAMES utf8
7 Init DB promls_box
7 Query select * from message_listing where (company_id = 7 or agency_id =7 ) and ( broker_id =2 ) and readed !=1 limit 0,5
7 Query SELECT FOUND_ROWS() AS total_results
7 Query SET NAMES utf8
7 Init DB promls_box
7 Query select * from message_listing where message_type = 'networking' and (category_message ='all' or (category_message='city' and area_id = 588 ) or (category_message='estate' and area_id = 272 ) or (category_message='agency' and company_id = 7 )) limit 0,5
7 Query SELECT FOUND_ROWS() AS total_results
7 Query SET NAMES utf8
7 Init DB promls_box
7 Query select SQL_CALC_FOUND_ROWS id , name, contact, email_contact, phone_contact, address, phone,
fax, email, website, creation_date, last_modification, area_id, area, status , logo, type, owner_id, users,
creator, creator_id
from companies_listing where status = 'active' and type in( 'sponsor' )
7 Query SELECT FOUND_ROWS() AS total_results
110211 0:34:20 7 Quit
110211 0:34:44 8 Connect promls_sysdba@localhost on
8 Query SET NAMES utf8
8 Init DB promls_box
8 Query select id , fullname from users where company_id = 7
8 Query SELECT FOUND_ROWS() AS total_results
8 Query select id , name from groups where company_id = 7 and context = "agency"
8 Query SELECT FOUND_ROWS() AS total_results
110211 0:35:01 9 Connect root@localhost on
9 Query show processlist
9 Quit
110211 0:35:16 8 Query SET NAMES utf8
8 Init DB promls_box
8 Query SELECT SQL_CALC_FOUND_ROWS property_id, property_type,property_name, bathrooms, bedrooms, for_sale, for_rent, for_vacational, units,
city,estate,country, rent_price, sale_price, min_price,mid_price, hig_price, max_sale,min_sale, min_rent, max_rent, min_vrental,max_vrental,
negotiation,property_status,
category_es category, image, dev_logo, inventory,company_id,broker_id FROM property_listing where property_status in('active','active-rented','active-sold') group by parent order by min_price asc, mid_price asc, hig_price asc, rent_price asc, sale_price asc limit 0, 10
110211 0:35:17 8 Query SELECT FOUND_ROWS() AS total_results
8 Query SET NAMES utf8
8 Init DB promls_box
8 Query select st.id estate_id,st.description estate from active_locations group by estate_id
8 Query SELECT FOUND_ROWS() AS total_results
8 Query select city_id , city from active_locations where estate_id =272 group by city_id
8 Query SELECT FOUND_ROWS() AS total_results
8 Query SET NAMES utf8
8 Init DB promls_box
8 Query select f.id, f.name_es as name from families f inner join category_types ct on ct.category = f.id where type='category' group by f.id
8 Query SELECT FOUND_ROWS() AS total_results
8 Query select t.id, t.name_es as name from property_types t inner join category_types ct on ct.property_type = t.id where ct.category =12
8 Query SELECT FOUND_ROWS() AS total_results
110211 0:35:43 10 Connect promls_sysdba@localhost on
10 Query SET NAMES utf8
10 Init DB promls_box
10 Query select id , fullname from users where company_id = 7
10 Query SELECT FOUND_ROWS() AS total_results
10 Query select id , name from groups where company_id = 7 and context = "agency"
10 Query SELECT FOUND_ROWS() AS total_results
8 Quit
110211 0:36:08 10 Query SET NAMES utf8
10 Init DB promls_box
10 Query SELECT SQL_CALC_FOUND_ROWS property_id, property_type,property_name, bathrooms, bedrooms, for_sale, for_rent, for_vacational, units,
city,estate,country, rent_price, sale_price, min_price,mid_price, hig_price, max_sale,min_sale, min_rent, max_rent, min_vrental,max_vrental,
negotiation,property_status,
category_es category, image, dev_logo, inventory,company_id,broker_id FROM property_listing where property_status in('active','active-rented','active-sold') group by parent order by min_price asc, mid_price asc, hig_price asc, rent_price asc, sale_price asc limit 0, 10
10 Query SELECT FOUND_ROWS() AS total_results
10 Query SET NAMES utf8
10 Init DB promls_box
10 Query select st.id estate_id,st.description estate from active_locations group by estate_id
10 Query SELECT FOUND_ROWS() AS total_results
10 Query select city_id , city from active_locations where estate_id =272 group by city_id
10 Query SELECT FOUND_ROWS() AS total_results
10 Query SET NAMES utf8
10 Init DB promls_box
10 Query select f.id, f.name_es as name from families f inner join category_types ct on ct.category = f.id where type='category' group by f.id
10 Query SELECT FOUND_ROWS() AS total_results
10 Query select t.id, t.name_es as name from property_types t inner join category_types ct on ct.property_type = t.id where ct.category =12
10 Query SELECT FOUND_ROWS() AS total_results
110211 0:36:21 10 Quit
110211 0:36:22 11 Connect promls_sysdba@localhost on
11 Query SET NAMES utf8
11 Init DB promls_box
11 Query select id , fullname from users where company_id = 7
11 Query SELECT FOUND_ROWS() AS total_results
11 Query select id , name from groups where company_id = 7 and context = "agency"
11 Query SELECT FOUND_ROWS() AS total_results
从php到mysql的连接看起来花了很多时间，我怎么能解决这个问题？
答案 0 :(得分：1)
我发现你的日志比有用更令人困惑;这些查询中没有一个看起来特别复杂，但话又说回来，我不知道你的表结构是什么样的，你有多少服务器负载，或者你的表中有多少条记录。如果查询本身实际上运行得非常慢，您可能需要查看表是否已正确编入索引。如果你谷歌关于mysql索引你可以找到大量的信息，如果你真的想进入它，看看这本电子书： http://sql-performance-explained.com/
我还注意到有一些查询一起使用ORDER BY和LIMIT语句。在这种情况下，您应该查看这两个命令在一起的关系，以及如何优化这些类型的查询。请访问此站点以获取更多信息：
http://www.mysqlperformanceblog.com/2006/09/01/order-by-limit-performance-optimization/
但是，如果它不是查询，那么就像你建议MySQL很难创建与数据库的连接。如果你有很多用户，可能是你的可用连接太少，你需要增加MySQL允许的连接数。请看这里如何做到这一点：
http://rackerhacker.com/2007/01/24/increase-mysql-connection-limit/
另一方面，你可能想考虑在PHP应用程序中使用持久连接，如果它需要很长时间才能连接到数据库。
http://php.net/manual/en/features.persistent-connections.php
这些可以减少PHP花在连接数据库上的时间。或者，如果您已经在使用持久连接，那么可能是您的PHP代码中存在错误，即创建连接，启动事务，然后保持连接，并占用连接，不留任何可用连接其他用户。当您的PHP应用程序与数据库连接时，请确保使用正确的错误处理。
同样，根据你所展示的内容，这些只是我最好的猜测之一。我希望它能让你朝着正确的方向前进。
答案 1 :(得分：0)
我继承了一个可怕的PHP后端，它有一些错误，可以让它查询数百次（对于站点索引页最多600个）。客户端不会付钱进行必要的后端重写，但我想加快速度。
在一个小型数据库上查询都很小，但后端连接并为每个查询选择一个数据库。
我编写了以下快速代码，以尽量减少这部分流量：
function DBConnectOnce($dbhost, $dbname, $dbuser, $dbpasswd) {
$GLOBALS['dbrecord_Debug'] = ($dbDebug == 'true'); // @TODO better way to handle this within the class?
if(isset($GLOBALS['DBRECORDCONFIGSTATUS'])&&$GLOBALS['DBRECORDCONFIGSTATUS']==$dbuser.$dbname.$dbhost){//check to see if the connectionon the proper type has been made.
$dblink=unserialize($GLOBALS['DBRECORDCONNECTION']);
} else {
$GLOBALS['DBRECORDCONFIGSTATUS']=$dbuser.$dbname.$dbhost;
$GLOBALS['DBRECORDCONNECTION']=serialize($dblink = mysql_connect($dbhost, $dbuser, $dbpasswd));
if($dblink === false) {
trigger_error("DBConnectOnce: Unable to connect to database server - ".mysql_error(), E_USER_ERROR);
}
if(!mysql_select_db($dbname)) {
trigger_error("DBConnectOnce: Unable to select database - $dbname at $dbhost", E_USER_ERROR);
}
}
return $dblink;
}
它使用全局变量来检查您已经建立的数据库连接类型，如果它与您需要进行的数据库连接类型匹配，则使用它。