搜尋
首頁資料庫mysql教程[mysqldumpslow 出错] Died at /usr/local/mysql/bin/mysqldumps
[mysqldumpslow 出错] Died at /usr/local/mysql/bin/mysqldumps
WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB
WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB
Jun 07, 2016 pm 04:25 PM
usr出錯

[mysqldumpslow 报错] Died at /usr/local/mysql/bin/mysqldumpslow line 161, chunk 236. mysqldumpslow报错： Died at /usr/local/mysql/bin/mysqldumpslow line 161, chunk 236. 总结：是因为top数目太多了，mysqldumpslow遍历不过来的缘故。 /usr/local/m

[mysqldumpslow 报错] Died at /usr/local/mysql/bin/mysqldumpslow line 161, chunk 236.

mysqldumpslow报错：Died at /usr/local/mysql/bin/mysqldumpslow line 161, chunk 236.

总结：是因为top数目太多了，mysqldumpslow遍历不过来的缘故。

/usr/local/mysql/bin/mysqldumpslow -s -t 15 /root/db01-102-slow.log 


1，把r去掉试试，还是报错，参数不识别。

[root@slave ]# /usr/local/mysql/bin/mysqldumpslow -s -t 15 /root/db01-102-slow.log 

Reading mysql slow query log from 15 /root/db01-102-slow.log
Can't open 15: 没有那个文件或目录 at /usr/local/mysql/bin/mysqldumpslow line 91.
Count: 22  Time=9.61s (211s)  Lock=0.00s (0s)  Rows=1.0 (22), [dubbo]@2hosts
  select count(*)
  from coupon_lot
  left join coupon 
  on coupon.coupon_lot_id = coupon_lot.coupon_lot_id
  LEFT JOIN brand
  ON brand.brand_id=coupon_lot.brand_id
  LEFT JOIN product_category
  on product_category.category_id=coupon_lot.category_id

Count: 177  Time=1.40s (247s)  Lock=0.00s (0s)  Rows=1.0 (177), [dubbo]@2hosts
  select count(*) from user_info
  LEFT JOIN system_region a
  ON province_id =a.region_id
  LEFT JOIN system_region b
  ON city_id = b.region_id
  LEFT JOIN system_region c
  ON district_id = c.region_id

Count: 22  Time=13.20s (290s)  Lock=0.00s (0s)  Rows=10.0 (220), [dubbo]@2hosts
  select 
  coupon_id, coupon_lot.coupon_lot_id, coupon_lot.remark,
  coupon.code,  coupon_lot.coupon_type, coupon.state,
  coupon_lot.ckey, coupon_lot.cvalue, coupon_lot.discount, coupon_lot.type, coupon_lot.channel, 
  coupon_lot.is_reusable, coupon_lot.start_datetime,
  coupon_lot.end_datetime, coupon_lot.create_datetime, coupon.update_datetime ,coupon_lot.department,
  coupon_lot.state as couponLotState, coupon_lot.create_operator,coupon_lot.coupon_category,
  coupon_lot.pdt_code,brand.brand_name,product_category.category_name
  from coupon_lot
  left join coupon 
  on coupon.coupon_lot_id = coupon_lot.coupon_lot_id
  LEFT JOIN brand
  ON brand.brand_id=coupon_lot.brand_id
  LEFT JOIN product_category
  on product_category.category_id=coupon_lot.category_id
  group by coupon_lot.coupon_lot_id
  order by coupon_lot.create_datetime DESC
  limit N,N

Count: 8  Time=1.09s (8s)  Lock=0.00s (0s)  Rows=10.0 (80), [dubbo]@2hosts
  select 
  return_sn,  relating_order_sn, return_from,  oi.order_out_sn ,
  add_time , return_type, 
  return_pay, ui.usename as userName, return_consignee, return_goods_count ,
  return_total_fee, total_paid, 
  return_desc, return_order_status,  return_pay_status ,
  return_shipping_status, order_return.lock_operator, order_return.return_invoice_no
  from order_return  LEFT JOIN   order_info oi
  on order_return.relating_order_sn = oi.order_sn 
  left join user_info ui on oi.user_id = ui.user_id
  left join order_payment on order_payment.order_sn = oi.order_sn
  order by order_return.add_time DESC
  limit N,N

Count: 1  Time=1.00s (1s)  Lock=0.00s (0s)  Rows=1.0 (1), root[root]@localhost
  select sleep(N)

Count: 1  Time=1.13s (1s)  Lock=0.00s (0s)  Rows=10.0 (10), [dubbo]@[xx]
  select 
  return_sn,  relating_order_sn, return_from,  oi.order_out_sn ,
  add_time , return_type, 
  return_pay, ui.usename as userName, return_consignee, return_goods_count ,
  return_total_fee, total_paid, 
  return_desc, return_order_status,  return_pay_status ,
  return_shipping_status, order_return.lock_operator, order_return.return_invoice_no
  from order_return  LEFT JOIN   order_info oi
  on order_return.relating_order_sn = oi.order_sn 
  left join user_info ui on oi.user_id = ui.user_id
  left join order_payment on order_payment.order_sn = oi.order_sn
  order by order_return.add_time DESC
  , oi.order_sn 
  limit N,N

Count: 5  Time=2.47s (12s)  Lock=0.00s (0s)  Rows=0.0 (0), [dubbo]@2hosts
  select
  user_id, usename, nickname, password, user_group_id, realname, gender, email, mobilephone, 
  birthday, province_id, city_id, district_id, marry, income, remarks, create_datetime, 
  active_state, verityEmail, verityPhone, credit, last_login, last_ip, is_locked, channel, 
  tag, union_partner_uuid, union_user_safekey, is_black, qq, weibo_id, verity_email_key, 
  verity_phone_key, verity_email_datetime, verity_phone_datetime, verity_question, 
  verity_answer, cps_code, cps_time_from, cps_time_to, cps_cookie, first_channel
  from user_info where mobilephone = 'S' and (channel is null or trim(channel) ='S')

2，查看下mysqldumpslow 使用参数，-s后面需要带参数的，看了西夏at比较合适

[root@db-master-2 ~]# /usr/local/mysql/bin/mysqldumpslow  --help
Usage: mysqldumpslow [ OPTS... ] [ LOGS... ]

Parse and summarize the MySQL slow query log. Options are

  --verbose    verbose
  --debug      debug
  --help       write this text to standard output

  -v           verbose
  -d           debug
  -s ORDER     what to sort by (al, at, ar, c, l, r, t), 'at' is default
                al: average lock time
                ar: average rows sent
                at: average query time
                 c: count
                 l: lock time
                 r: rows sent
                 t: query time  
  -r           reverse the sort order (largest last instead of first)
  -t NUM       just show the top n queries
  -a           don't abstract all numbers to N and strings to 'S'
  -n NUM       abstract numbers with at least n digits within names
  -g PATTERN   grep: only consider stmts that include this string
  -h HOSTNAME  hostname of db server for *-slow.log filename (can be wildcard),
               default is '*', i.e. match all
  -i NAME      name of server instance (if using mysql.server startup script)
  -l           don't subtract lock time from total time


3，在mysqldumpslow的-s后面加入 at参数试试：  [root@slave ]# /usr/local/mysql/bin/mysqldumpslow -s at -t 15 /root/db01-102-slow.log 

[root@db-master-2 ~]# /usr/local/mysql/bin/mysqldumpslow -s at -t 15 /root/db01-102-slow.log 
Reading mysql slow query log from /root/db01-102-slow.log
Count: 22  Time=13.20s (290s)  Lock=0.00s (0s)  Rows=10.0 (220), [dubbo]@2hosts
  select 
  coupon_id, coupon_lot.coupon_lot_id, coupon_lot.remark,
  coupon.code,  coupon_lot.coupon_type, coupon.state,
  coupon_lot.ckey, coupon_lot.cvalue, coupon_lot.discount, coupon_lot.type, coupon_lot.channel, 
  coupon_lot.is_reusable, coupon_lot.start_datetime,
  coupon_lot.end_datetime, coupon_lot.create_datetime, coupon.update_datetime ,coupon_lot.department,
  coupon_lot.state as couponLotState, coupon_lot.create_operator,coupon_lot.coupon_category,
  coupon_lot.pdt_code,brand.brand_name,product_category.category_name
  from coupon_lot
  left join coupon 
  on coupon.coupon_lot_id = coupon_lot.coupon_lot_id
  LEFT JOIN brand
  ON brand.brand_id=coupon_lot.brand_id
  LEFT JOIN product_category
  on product_category.category_id=coupon_lot.category_id
  group by coupon_lot.coupon_lot_id
  order by coupon_lot.create_datetime DESC
  limit N,N

Count: 22  Time=9.61s (211s)  Lock=0.00s (0s)  Rows=1.0 (22), [dubbo]@2hosts
  select count(*)
  from coupon_lot
  left join coupon 
  on coupon.coupon_lot_id = coupon_lot.coupon_lot_id
  LEFT JOIN brand
  ON brand.brand_id=coupon_lot.brand_id
  LEFT JOIN product_category
  on product_category.category_id=coupon_lot.category_id

Count: 5  Time=2.47s (12s)  Lock=0.00s (0s)  Rows=0.0 (0), [dubbo]@2hosts
  select
  user_id, usename, nickname, password, user_group_id, realname, gender, email, mobilephone, 
  birthday, province_id, city_id, district_id, marry, income, remarks, create_datetime, 
  active_state, verityEmail, verityPhone, credit, last_login, last_ip, is_locked, channel, 
  tag, union_partner_uuid, union_user_safekey, is_black, qq, weibo_id, verity_email_key, 
  verity_phone_key, verity_email_datetime, verity_phone_datetime, verity_question, 
  verity_answer, cps_code, cps_time_from, cps_time_to, cps_cookie, first_channel
  from user_info where mobilephone = 'S' and (channel is null or trim(channel) ='S')

Count: 177  Time=1.40s (247s)  Lock=0.00s (0s)  Rows=1.0 (177), [dubbo]@2hosts
  select count(*) from user_info
  LEFT JOIN system_region a
  ON province_id =a.region_id
  LEFT JOIN system_region b
  ON city_id = b.region_id
  LEFT JOIN system_region c
  ON district_id = c.region_id

Count: 1  Time=1.13s (1s)  Lock=0.00s (0s)  Rows=10.0 (10), [dubbo]@[10.10.3.8]
  select 
  return_sn,  relating_order_sn, return_from,  oi.order_out_sn ,
  add_time , return_type, 
  return_pay, ui.usename as userName, return_consignee, return_goods_count ,
  return_total_fee, total_paid, 
  return_desc, return_order_status,  return_pay_status ,
  return_shipping_status, order_return.lock_operator, order_return.return_invoice_no
  from order_return  LEFT JOIN   order_info oi
  on order_return.relating_order_sn = oi.order_sn 
  left join user_info ui on oi.user_id = ui.user_id
  left join order_payment on order_payment.order_sn = oi.order_sn
  order by order_return.add_time DESC
  , oi.order_sn 
  limit N,N

Count: 8  Time=1.09s (8s)  Lock=0.00s (0s)  Rows=10.0 (80), [dubbo]@2hosts
  select 
  return_sn,  relating_order_sn, return_from,  oi.order_out_sn ,
  add_time , return_type, 
  return_pay, ui.usename as userName, return_consignee, return_goods_count ,
  return_total_fee, total_paid, 
  return_desc, return_order_status,  return_pay_status ,
  return_shipping_status, order_return.lock_operator, order_return.return_invoice_no
  from order_return  LEFT JOIN   order_info oi
  on order_return.relating_order_sn = oi.order_sn 
  left join user_info ui on oi.user_id = ui.user_id
  left join order_payment on order_payment.order_sn = oi.order_sn
  order by order_return.add_time DESC
  limit N,N

Count: 1  Time=1.00s (1s)  Lock=0.00s (0s)  Rows=1.0 (1), root[root]@localhost
  select sleep(N)

Died at /usr/local/mysql/bin/mysqldumpslow line 161,  chunk 236.
看到后面还是报错：Died at /usr/local/mysql/bin/mysqldumpslow line 161, chunk 236.

4，去看看/usr/local/mysql/bin/mysqldumpslow的第161行左右，到底是在操作什么脚本。

156 my @sorted = sort { $stmt{$b}->{$opt{s}}  $stmt{$a}->{$opt{s}} } keys %stmt;
157 @sorted = @sorted[0 .. $opt{t}-1] if $opt{t};
158 @sorted = reverse @sorted         if $opt{r};
159 
160 foreach (@sorted) {
161     my $v = $stmt{$_} || die;
162     my ($c, $t,$at, $l,$al, $r,$ar) = @{ $v }{qw(c t at l al r ar)};
163     my @users = keys %{$v->{users}};
164     my $user  = (@users==1) ? $users[0] : sprintf "%dusers",scalar @users;
165     my @hosts = keys %{$v->{hosts}};
166     my $host  = (@hosts==1) ? $hosts[0] : sprintf "%dhosts",scalar @hosts;
167     printf "Count: %d  Time=%.2fs (%ds)  Lock=%.2fs (%ds)  Rows=%.1f (%d), $user\@$host\n%s\n\n",
168             $c, $at,$t, $al,$l, $ar,$r, $_;
169 }
170 
171 sub usage {
172     my $str= shift;
看到主要是foreach (@sorted)遍历函数，也就是遍历到chunk 236的时候就died结束了，没有办法往下继续foreach了。因为以前写过代码，知道报错所在的这一行

 my $v = $stmt{$_} || die;
是遍历第一句，那么肯定是赋值语句，报错Died，chunk 236肯定是已经遍历到末尾没有数据了，看这个函数没有判断传入的参数是否为null的逻辑，所以当文件数据已经遍历完，但是命令还没有结束，所以继续遍历，遍历null的时候报错，所以进程中止了，解决办法就是做个限制不要遍历超过原始数据的字符串长度。那么我们再来看执行的命令:

 /usr/local/mysql/bin/mysqldumpslow -s at -t 15 /root/db01-102-slow.log 有 -t 15这一句，那么就是要显示出前15个记录，那么如果我的slow.log统计出来只有12个不到15个，而这里有继续遍历到15的话，那进程肯定会Died。


所以这里有2个解决方法：

1 修改/usr/local/mysql/bin/mysqldumpslow里面的源代码，加null判断。

这个过程有些复杂，暂时略过吧，期待后续空了再研究。


2 修改命令  /usr/local/mysql/bin/mysqldumpslow -s at -t 15 /root/db01-102-slow.log ，把-t 15修改成-t 10或者-t 5试试。

试了好几次，发现临界点在-t 7上面，如下：

[root@slave~]# /usr/local/mysql/bin/mysqldumpslow -s at -t 8 /root/db01-102-slow.log 
Reading mysql slow query log from /root/db01-102-slow.log
Count: 22  Time=13.20s (290s)  Lock=0.00s (0s)  Rows=10.0 (220), [dubbo]@2hosts
  select 
  coupon_id, coupon_lot.coupon_lot_id, coupon_lot.remark,
  coupon.code,  coupon_lot.coupon_type, coupon.state,
  coupon_lot.ckey, coupon_lot.cvalue, coupon_lot.discount, coupon_lot.type, coupon_lot.channel, 
  coupon_lot.is_reusable, coupon_lot.start_datetime,
  coupon_lot.end_datetime, coupon_lot.create_datetime, coupon.update_datetime ,coupon_lot.department,
  coupon_lot.state as couponLotState, coupon_lot.create_operator,coupon_lot.coupon_category,
  coupon_lot.pdt_code,brand.brand_name,product_category.category_name
  from coupon_lot
  left join coupon 
  on coupon.coupon_lot_id = coupon_lot.coupon_lot_id
  LEFT JOIN brand
  ON brand.brand_id=coupon_lot.brand_id
  LEFT JOIN product_category
  on product_category.category_id=coupon_lot.category_id
  group by coupon_lot.coupon_lot_id
  order by coupon_lot.create_datetime DESC
  limit N,N

Count: 22  Time=9.61s (211s)  Lock=0.00s (0s)  Rows=1.0 (22), [dubbo]@2hosts
  select count(*)
  from coupon_lot
  left join coupon 
  on coupon.coupon_lot_id = coupon_lot.coupon_lot_id
  LEFT JOIN brand
  ON brand.brand_id=coupon_lot.brand_id
  LEFT JOIN product_category
  on product_category.category_id=coupon_lot.category_id

Count: 5  Time=2.47s (12s)  Lock=0.00s (0s)  Rows=0.0 (0), [dubbo]@2hosts
  select
  user_id, usename, nickname, password, user_group_id, realname, gender, email, mobilephone, 
  birthday, province_id, city_id, district_id, marry, income, remarks, create_datetime, 
  active_state, verityEmail, verityPhone, credit, last_login, last_ip, is_locked, channel, 
  tag, union_partner_uuid, union_user_safekey, is_black, qq, weibo_id, verity_email_key, 
  verity_phone_key, verity_email_datetime, verity_phone_datetime, verity_question, 
  verity_answer, cps_code, cps_time_from, cps_time_to, cps_cookie, first_channel
  from user_info where mobilephone = 'S' and (channel is null or trim(channel) ='S')

Count: 177  Time=1.40s (247s)  Lock=0.00s (0s)  Rows=1.0 (177), [xx]@2hosts
  select count(*) from user_info
  LEFT JOIN system_region a
  ON province_id =a.region_id
  LEFT JOIN system_region b
  ON city_id = b.region_id
  LEFT JOIN system_region c
  ON district_id = c.region_id

Count: 1  Time=1.13s (1s)  Lock=0.00s (0s)  Rows=10.0 (10), [xx]@[xxx]
  select 
  return_sn,  relating_order_sn, return_from,  oi.order_out_sn ,
  add_time , return_type, 
  return_pay, ui.usename as userName, return_consignee, return_goods_count ,
  return_total_fee, total_paid, 
  return_desc, return_order_status,  return_pay_status ,
  return_shipping_status, order_return.lock_operator, order_return.return_invoice_no
  from order_return  LEFT JOIN   order_info oi
  on order_return.relating_order_sn = oi.order_sn 
  left join user_info ui on oi.user_id = ui.user_id
  left join order_payment on order_payment.order_sn = oi.order_sn
  order by order_return.add_time DESC
  , oi.order_sn 
  limit N,N

Count: 8  Time=1.09s (8s)  Lock=0.00s (0s)  Rows=10.0 (80), [xx]@2hosts
  select 
  return_sn,  relating_order_sn, return_from,  oi.order_out_sn ,
  add_time , return_type, 
  return_pay, ui.usename as userName, return_consignee, return_goods_count ,
  return_total_fee, total_paid, 
  return_desc, return_order_status,  return_pay_status ,
  return_shipping_status, order_return.lock_operator, order_return.return_invoice_no
  from order_return  LEFT JOIN   order_info oi
  on order_return.relating_order_sn = oi.order_sn 
  left join user_info ui on oi.user_id = ui.user_id
  left join order_payment on order_payment.order_sn = oi.order_sn
  order by order_return.add_time DESC
  limit N,N

Count: 1  Time=1.00s (1s)  Lock=0.00s (0s)  Rows=1.0 (1), root[root]@localhost
  select sleep(N)

Died at /usr/local/mysql/bin/mysqldumpslow line 161,  chunk 236.

-- 临界点 -t 7
[root@db-master-2 ~]# /usr/local/mysql/bin/mysqldumpslow -s at -t 7 /root/db01-102-slow.log 

Reading mysql slow query log from /root/db01-102-slow.log
Count: 22  Time=13.20s (290s)  Lock=0.00s (0s)  Rows=10.0 (220), [xx]@2hosts
  select 
  coupon_id, coupon_lot.coupon_lot_id, coupon_lot.remark,
  coupon.code,  coupon_lot.coupon_type, coupon.state,
  coupon_lot.ckey, coupon_lot.cvalue, coupon_lot.discount, coupon_lot.type, coupon_lot.channel, 
  coupon_lot.is_reusable, coupon_lot.start_datetime,
  coupon_lot.end_datetime, coupon_lot.create_datetime, coupon.update_datetime ,coupon_lot.department,
  coupon_lot.state as couponLotState, coupon_lot.create_operator,coupon_lot.coupon_category,
  coupon_lot.pdt_code,brand.brand_name,product_category.category_name
  from coupon_lot
  left join coupon 
  on coupon.coupon_lot_id = coupon_lot.coupon_lot_id
  LEFT JOIN brand
  ON brand.brand_id=coupon_lot.brand_id
  LEFT JOIN product_category
  on product_category.category_id=coupon_lot.category_id
  group by coupon_lot.coupon_lot_id
  order by coupon_lot.create_datetime DESC
  limit N,N

Count: 22  Time=9.61s (211s)  Lock=0.00s (0s)  Rows=1.0 (22), [dubbo]@2hosts
  select count(*)
  from coupon_lot
  left join coupon 
  on coupon.coupon_lot_id = coupon_lot.coupon_lot_id
  LEFT JOIN brand
  ON brand.brand_id=coupon_lot.brand_id
  LEFT JOIN product_category
  on product_category.category_id=coupon_lot.category_id

Count: 5  Time=2.47s (12s)  Lock=0.00s (0s)  Rows=0.0 (0), [xx]@2hosts
  select
  user_id, usename, nickname, password, user_group_id, realname, gender, email, mobilephone, 
  birthday, province_id, city_id, district_id, marry, income, remarks, create_datetime, 
  active_state, verityEmail, verityPhone, credit, last_login, last_ip, is_locked, channel, 
  tag, union_partner_uuid, union_user_safekey, is_black, qq, weibo_id, verity_email_key, 
  verity_phone_key, verity_email_datetime, verity_phone_datetime, verity_question, 
  verity_answer, cps_code, cps_time_from, cps_time_to, cps_cookie, first_channel
  from user_info where mobilephone = 'S' and (channel is null or trim(channel) ='S')

Count: 177  Time=1.40s (247s)  Lock=0.00s (0s)  Rows=1.0 (177), [xx]@2hosts
  select count(*) from user_info
  LEFT JOIN system_region a
  ON province_id =a.region_id
  LEFT JOIN system_region b
  ON city_id = b.region_id
  LEFT JOIN system_region c
  ON district_id = c.region_id

Count: 1  Time=1.13s (1s)  Lock=0.00s (0s)  Rows=10.0 (10), [dubbo]@[xxx]
  select 
  return_sn,  relating_order_sn, return_from,  oi.order_out_sn ,
  add_time , return_type, 
  return_pay, ui.usename as userName, return_consignee, return_goods_count ,
  return_total_fee, total_paid, 
  return_desc, return_order_status,  return_pay_status ,
  return_shipping_status, order_return.lock_operator, order_return.return_invoice_no
  from order_return  LEFT JOIN   order_info oi
  on order_return.relating_order_sn = oi.order_sn 
  left join user_info ui on oi.user_id = ui.user_id
  left join order_payment on order_payment.order_sn = oi.order_sn
  order by order_return.add_time DESC
  , oi.order_sn 
  limit N,N

Count: 8  Time=1.09s (8s)  Lock=0.00s (0s)  Rows=10.0 (80), [dubbo]@2hosts
  select 
  return_sn,  relating_order_sn, return_from,  oi.order_out_sn ,
  add_time , return_type, 
  return_pay, ui.usename as userName, return_consignee, return_goods_count ,
  return_total_fee, total_paid, 
  return_desc, return_order_status,  return_pay_status ,
  return_shipping_status, order_return.lock_operator, order_return.return_invoice_no
  from order_return  LEFT JOIN   order_info oi
  on order_return.relating_order_sn = oi.order_sn 
  left join user_info ui on oi.user_id = ui.user_id
  left join order_payment on order_payment.order_sn = oi.order_sn
  order by order_return.add_time DESC
  limit N,N

Count: 1  Time=1.00s (1s)  Lock=0.00s (0s)  Rows=1.0 (1), root[root]@localhost
  select sleep(N)

[root@db-master-2 ~]#

最终总结：
mysqldumpslow报错：Died at /usr/local/mysql/bin/mysqldumpslow line 161, chunk 236. 是因为top数目太多了，mysqldumpslow遍历不过来的缘故。

陳述
本文內容由網友自願投稿，版權歸原作者所有。本站不承擔相應的法律責任。如發現涉嫌抄襲或侵權的內容，請聯絡admin@php.cn
相關文章
如何使用Alter Table語句在MySQL中更改表？如何使用Alter Table語句在MySQL中更改表？Mar 19, 2025 pm 03:51 PM

本文討論了使用MySQL的Alter Table語句修改表，包括添加/刪除列，重命名表/列以及更改列數據類型。

如何為MySQL連接配置SSL/TLS加密？如何為MySQL連接配置SSL/TLS加密？Mar 18, 2025 pm 12:01 PM

文章討論了為MySQL配置SSL/TLS加密，包括證書生成和驗證。主要問題是使用自簽名證書的安全含義。[角色計數：159]

您如何處理MySQL中的大型數據集？您如何處理MySQL中的大型數據集？Mar 21, 2025 pm 12:15 PM

文章討論了處理MySQL中大型數據集的策略，包括分區，碎片，索引和查詢優化。

哪些流行的MySQL GUI工具（例如MySQL Workbench，PhpMyAdmin）是什麼？哪些流行的MySQL GUI工具（例如MySQL Workbench，PhpMyAdmin）是什麼？Mar 21, 2025 pm 06:28 PM

文章討論了流行的MySQL GUI工具，例如MySQL Workbench和PhpMyAdmin，比較了它們對初學者和高級用戶的功能和適合性。[159個字符]

如何使用Drop Table語句將表放入MySQL中？如何使用Drop Table語句將表放入MySQL中？Mar 19, 2025 pm 03:52 PM

本文討論了使用Drop Table語句在MySQL中放下表，並強調了預防措施和風險。它強調，沒有備份，該動作是不可逆轉的，詳細介紹了恢復方法和潛在的生產環境危害。

您如何用外國鑰匙代表關係？您如何用外國鑰匙代表關係？Mar 19, 2025 pm 03:48 PM

文章討論了使用外國密鑰來代表數據庫中的關係，重點是最佳實踐，數據完整性和避免的常見陷阱。

如何在JSON列上創建索引？如何在JSON列上創建索引？Mar 21, 2025 pm 12:13 PM

本文討論了在PostgreSQL，MySQL和MongoDB等各個數據庫中的JSON列上創建索引，以增強查詢性能。它解釋了索引特定的JSON路徑的語法和好處，並列出了支持的數據庫系統。

如何保護MySQL免受常見漏洞（SQL注入，蠻力攻擊）？如何保護MySQL免受常見漏洞（SQL注入，蠻力攻擊）？Mar 18, 2025 pm 12:00 PM

文章討論了使用準備好的語句，輸入驗證和強密碼策略確保針對SQL注入和蠻力攻擊的MySQL。（159個字符）

See all articles

熱AI工具

Undresser.AI Undress

Undresser.AI Undress

人工智慧驅動的應用程序，用於創建逼真的裸體照片

AI Clothes Remover

AI Clothes Remover

用於從照片中去除衣服的線上人工智慧工具。

Undress AI Tool

Undress AI Tool

免費脫衣圖片

Clothoff.io

Clothoff.io

AI脫衣器

AI Hentai Generator

AI Hentai Generator

免費產生 AI 無盡。

顯示更多

熱門文章

R.E.P.O.能量晶體解釋及其做什麼（黃色晶體）
3 週前By尊渡假赌尊渡假赌尊渡假赌
R.E.P.O.最佳圖形設置
3 週前By尊渡假赌尊渡假赌尊渡假赌
刺客信條陰影：貝殼謎語解決方案
1 週前ByDDD
R.E.P.O.如果您聽不到任何人，如何修復音頻
3 週前By尊渡假赌尊渡假赌尊渡假赌
在哪裡可以找到原子中的起重機控制鑰匙卡
1 週前ByDDD
顯示更多

熱工具

SublimeText3 Mac版

SublimeText3 Mac版

神級程式碼編輯軟體(SublimeText3)

PhpStorm Mac 版本

PhpStorm Mac 版本

最新（2018.2.1 ）專業的PHP整合開發工具

Atom編輯器mac版下載

Atom編輯器mac版下載

最受歡迎的的開源編輯器

mPDF

mPDF

mPDF是一個PHP庫，可以從UTF-8編碼的HTML產生PDF檔案。原作者Ian Back編寫mPDF以從他的網站上「即時」輸出PDF文件，並處理不同的語言。與原始腳本如HTML2FPDF相比，它的速度較慢，並且在使用Unicode字體時產生的檔案較大，但支援CSS樣式等，並進行了大量增強。支援幾乎所有語言，包括RTL（阿拉伯語和希伯來語）和CJK（中日韓）。支援嵌套的區塊級元素（如P、DIV），

Dreamweaver Mac版

Dreamweaver Mac版

視覺化網頁開發工具

顯示更多

熱門話題

gmail信箱登陸入口在哪裡
7444
15
CakePHP 教程
1371
52
steam的賬戶名稱是什麼格式
76
11
win11激活密鑰永久
38
19
NYT連接提示和答案
9
6
顯示更多