Tag：Increase of efficiency
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Time：2021-9-19
1. Can have return value2. Exceptions can be thrown3. Different methods, run() / call() Code test package com.hudu.demo01.callable; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; import java.util.concurrent.FutureTask; public class CallableTest { public static void main(String[] args) throws ExecutionException, InterruptedException { // new Thread(new MyThread()).start(); Class implements the runnable () interface // new Thread(new Runnable()).start(); // new Thread(new FutureTask<V>()).start();// […]
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Time：2021-8-4
We often compare the select results. For common functions such as minus, what can be done to improve the efficiency when the two tables have a large amount of data? Minus modeThe minus execution plan is shown as follows. Compare it after sortingselect object_id from t2 minus select object_id from t1;..2255 rows selected.Elapsed: 00:00:00.93Execution Plan […]
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Time：2021-6-28
Netease face to face (30 minutes) Self introduction, project introduction Introduce spring, IOC and AOP The implementation of AOP and the dynamic proxy are introduced in detail Set, HashMap, expansion mechanism Implementation of synchronized in JVM Lock lock process Deadlock, the scene describes the deadlock situation Garbage collection, accessibility analysis Creating tables with MySQL The […]
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Time：2021-3-19
From the beginning of CPP, one thing we will learn is how to exchange the values of two variables. Generally, we need to set a new variable to store the intermediate value, and then carry out the assignment operation. The method to be introduced below can save the space of creating a new variable, and […]
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Time：2020-9-10
Git branch quickly switches the shell of submitting code Objective: to simplify the process of submitting data to the development branch and improve the efficiency How to use it / quickCommit.sh Updated image loading method Complete code #!/bin/bash #Objective: to simplify the process of submitting data to the development branch and improve the efficiency #Step […]
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Time：2020-8-5
package com.io.buffered; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import org.junit.Test; /** *Using buffer stream to copy text files * */ public class BufferedStreamFileText { @Test public void copyTestTextTest() { //Recording time long start = System.currentTimeMillis(); String src = “./hello.txt”; String dest = “./world.txt”; copyTestText(src, dest); long end = System.currentTimeMillis(); System.out.println (“time […]
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Time：2020-8-4
Buffer stream to achieve file copy, you can image, video, zip, RAR and other files for operation package com.io.buffered; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import org.junit.Test; /** *Using buffer stream to copy files */ public class BufferedStreamFile { //Non text file copy @Test public void copyFileTest() { //Record the time […]
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Time：2020-7-14
Some problems encountered in the work about SQL query, sort out the records, and implement the environment sqlservice 2014 1、 On the same field, several ways to query multiple keywords Basic grammar: SELECT column_name(s) FROM table_name WHERE column_name LIKE pattern Tbuser: Id LastName FirstName 1 Adams John 2 Bush George 3 Carter Thomas Query […]
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Time：2020-5-14
From the perspective of the task types of computer processing, the two positions of programmer and product manager are characterized Programmer, make’s schedule: CPU bound type, parallel can improve efficiency Product manager, manager’s schedule: I / O bound type, concurrent can improve efficiency Therefore, the product manager should try not to disturb the programmers you […]
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Time：2020-2-10
Preface: If you are familiar with Linux commands, you may find thatls -landllThe effect is the same, so have you ever thought about why? What is command alias llIt is an alias defined in advance in Linux An alias is a name given to a command or a list of commands. You can use aliases […]
