Tag: dup

Java implements text duplication checking (similarity) without third-party tool version

Functional background: As business records gradually grow, duplicate project name data and duplicate content data gradually appear, which leads to a decline in the quality of project records. In order to avoid this situation from happening, we consider performing duplication checking on key data information. We originally planned to use a third-party standard duplication checking […]

How to find and delete duplicate rows in MySQL?

How to find duplicate rows The first step is to define what rows are duplicates. Most of the time it’s simple: some of their columns have the same values. This example uses this definition. Maybe your definition of “repeat” is very complicated and you need to make some modifications to the sql. Data samples to […]

Collection framework: characteristics of Set collection, underlying principles of HashSet collection, hash table, implementation of deduplication

Characteristics of Set collection Set is an unordered, non-repeating data structure. Its characteristics are as follows: 1. The elements in the set are unordered: The elements in the Set have no order and cannot be accessed through indexes. 2. The elements in the set are unique: Duplicate elements are not allowed in the Set, and […]

The nature of communication, communication methods, the principles and multiple characteristics of anonymous pipes (access control, pipe_buf, atomicity, half-duplex), pipe() + simulation implementation code, communication between multiple processes (anonymous pipes, simulation implementation code )

Table of Contents communication introduce Why should there be communication? the nature of communication How to communicate pipeline system V posix standard Signal pipeline introduce anonymous pipe Principle introduce process Implement — pipe() function prototype parameter return value mock code Features Used for communication between parent and child processes Provide access control When the buffer […]

LINUX Talk (Spend 10 minutes to learn blind box knowledge points) (perror, O_CREAT|O_RDWR, S_IRWXU, lseek, dup, system, struct stat statbuf, regular file bits)

ok friends, without further ado, let’s take a look at the code below! First question: if(fd1< 0) { perror(“open :”); printf(“errno is:%d \ “,errno); This code is used to handle the situation where the file fails to open: The open() function will return a non-negative file descriptor when the file is successfully opened, and -1 […]

RabbitMQ’s message loss, message duplication, and message backlog issues

In the previous article, I introduced the development plan of RabbitMQ to achieve distributed final consistency. This article will solve some problems in this plan. http://t.csdnimg.cn/aOYTH First, the three major problems of RabbitMQ: message loss, message duplication, and message backlog The most serious of these three problems is the problem of message loss. Then let […]

Collectors.toMap error: null pointer & duplicate key

The stream in Java 8 has been widely used by students in project development. Of course, everyone has also stepped on many pitfalls. Next, I will talk about the pitfalls of Collections.toMap in project use, so as to avoid being pitted again. 1. Introduction to Collectors.toMap Collectors.toMap is a collector in Java 8 that can […]