mysql - 查询花费很长时间在错误日志中发现锁定代码？

Question

当我出于报告目的执行一些查询时，有时这些查询需要 10 分钟，有时相同的查询需要几个小时，有时我们会收到诸如通信链接失败之类的错误。当我查看错误日志时，我发现下面的错误消息，如何修复它。

错误消息:

lock: 0x2b84f402e800:
lock: 0x2b84f401bb80:
lock: 0x2b84f401c410:
lock: 0x2b84f41d45f0:
lock: 0x2b84f41c1990:
lock: 0x22d657d0:
lock: 0x2308c650:
lock: 0x2b84f800d2c0:
lock: 0x22db4040:
lock: 0x22c0fa60:
lock: 0x22bc85a0:
lock: 0x22cf7710:

Key caches:
default
Buffer_size:     402653184
Block_size:           1024
Division_limit:        100
Age_limit:             300
blocks used:            19
not flushed:             0
w_requests:              1
writes:                  1
r_requests:            160
reads:                  19


handler status:
read_key:      8256766
read_next:   143651263
read_rnd         16764
read_first:      76853
write:         1941561
delete          306347
update:        1781864

Table status:
Opened tables:        149
Open tables:          142
Open files:            55
Open streams:           0

Alarm status:
Active alarms:   0
Max used alarms: 1
Next alarm time: 0
Memory status:
Non-mmapped space allocated from system: 368238592
Number of free chunks:                   168
Number of fastbin blocks:                0
Number of mmapped regions:               31
Space in mmapped regions:                761421824
Maximum total allocated space:           0
Space available in freed fastbin blocks: 0
Total allocated space:                   357157904
Total free space:                        11080688
Top-most, releasable space:              5359328
Estimated memory (with thread stack):    1132281856



Events status:
LLA = Last Locked At  LUA = Last Unlocked At
WOC = Waiting On Condition  DL = Data Locked

Event scheduler status:
State      : INITIALIZED
Thread id  : 0
LLA        : n/a:0
LUA        : n/a:0
WOC        : NO
Workers    : 0
Executed   : 0
Data locked: NO

Event queue status:
Element count   : 0
Data locked     : NO
Attempting lock : NO
LLA             : init_queue:139
LUA             : init_queue:149
WOC             : NO
Next activation : never
140328 17:17:08 [Warning] IP address 'xxxx' could not be resolved: Name or service not known
140328 17:20:00 [Warning] IP address 'xxxx' could not be resolved: Name or service not known
140328 17:29:43 [Warning] IP address 'xxxx' could not be resolved: Name or service not known
140331  9:55:47 [Warning] IP address 'xxxx' could not be resolved: Name or service not known
140331  9:56:09 [Warning] IP address 'xxxx' could not be resolved: Name or service not known
140331 11:38:35 [Warning] IP address 'xxxx' could not be resolved: Name or service not known
140331 15:07:04 [Warning] IP address 'xxxx' could not be resolved: Name or service not known

Answer 1

如果您出于报告目的进行查询，则不应锁定任何记录。确保您在查询语句中使用 with (nolock)。