MySQL - slow query log analysis
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MySQL - slow query log analysis
1. Start and set slow query log2. Data preparation3. Slow query log analysis tool: mysqldumpslow4. Delete slow query log5,show profile
MySQL - slow query log analysis
MySQL's slow query log is a kind of log record provided by mysql. It is used to record the statements whose response ...
Posted by razvypp on Tue, 02 Aug 2022 21:39:47 +0300
Echarts dynamically generates charts, switches chart types, and displays long data areas
Don't say much, let's start with the renderings! The frame rate is adjusted a little high, and the picture jumps as if it were reincarnated 😂😂， Please forgive me
If I happen to achieve something you need, please go inside - >
First of all, the whole content starts with the chart creation instance after the introduction of E ...
Posted by disconne on Tue, 02 Aug 2022 21:35:34 +0300
NIO Selector execution process
1, What is Seletor?
The literal meaning of selector is not easy to understand. Seletor is a listener that can listen to events in the Channel. Channels can be registered in the seletor. When these registered channels have events, the seletor's select method will return these events to the thread for processing.
2, The difference bet ...
Posted by Fari on Tue, 02 Aug 2022 21:10:27 +0300
JavaSE file operation and IO flow
File operation and IO flow
File class
summary
java. io. The file class is an abstract representation of the path names of files and directories. It is mainly used to create, find, and delete files and directories
Construction method
File(File parent, String child) Create a new File instance based on the parent abstract pathname and the chi ...
Posted by Asday on Mon, 01 Aug 2022 21:51:31 +0300
Qt realizes sdp packaging, sdp strategy introduction
sdp introduction
SDP: session des description protocol Session description protocol (SDP) provides multimedia session description for session notification, session invitation and other forms of multimedia session initialization. The SDP session description consists of multiple lines =. Where is a character. Is a string whose format depends on. ...
Posted by rkumar on Mon, 01 Aug 2022 21:33:17 +0300
LRU and LFU algorithm (page replacement algorithm)
Differences between LRU and LFU
Both LRU and LFU are page replacement algorithms for memory management.
LRU: Least Recently Used (longest time) elimination algorithm. LRU is the page that has not been used for the longest time.
LFU: Least Frequently Used. LFU is the least used page in a period of time.
example
Assume that th ...
Posted by latinofever on Mon, 01 Aug 2022 21:07:12 +0300
Kotlin - delay initialization and sealing classes
1, lateinit delay initialization keyword
Many syntax features in Kotlin, such as variable immutability, variable non nullability, and so on, are designed to ensure program safety as much as possible. For example, there are many global variable instances in your class. In order to ensure that they can meet Kotlin's null pointer check sta ...
Posted by Cut on Sun, 31 Jul 2022 22:28:16 +0300
Creation of NumPy array
1, NumPy create array
In addition to using the underlying ndarray constructor, the ndarray array can also be created in the following ways.
1.numpy.empty
numpy. The empty method is used to create an uninitialized array with a specified shape and data type:
numpy.empty(shape, dtype = float, order = 'C')
Â
shape
Array shape
dtype
Data type ...
Posted by lutzlutz896 on Sun, 31 Jul 2022 21:39:53 +0300
SpringBoot integration springcloud Alibaba Seata details
SpringCloud Alibab-Seata Introduction:
Seata is an open source distributed transaction solution, which is committed to providing high-performance and easy-to-use distributed transaction services under the microservice architecture.
Seata will provide users with AT, TCC, SAGA and XA transaction modes to create a one-stop distributed soluti ...
Posted by kporter.porter on Sun, 31 Jul 2022 21:07:19 +0300
Java from getting started to giving up 06 (what is object-oriented?)
What is object-oriented?
Process oriented
The process oriented method of solving problems is to follow the steps we have analyzed, step by step, follow the principle of top-down and gradual refinement, and focus on the process and steps of solving problems.
object-oriented
Java Language is an object-oriented programming language, and obj ...
Posted by the_ut_tick on Sat, 30 Jul 2022 22:17:10 +0300