MySQL benchmark tool

1, Benchmarking Benchmark is a kind of stress test for system design. Benchmarking is simplified stress testing. 1.1 common indicators TPS QPS response time Concurrency 1.2 script for data collection and analysis The shell script gather.sh for collecting data #!/bin/sh INTERVAL=5 PREFIX=$INTERVAL-sec-status RUNFILE=/home/benchmarks/running m ...

Posted on Sun, 05 Apr 2020 22:26:11 -0700 by Cheeseweasel

055.Python front end Django model ORM

In the process of centos experiment, pymql always had attribute errors, which made it difficult to find out the problems. A ubuntu desktop system was built again, and pycharm development tool was used as the learning and development tool. The specific reason was that there was a problem in project naming, which was in conflict with its own modu ...

Posted on Sun, 05 Apr 2020 21:30:19 -0700 by OM2

Learn Java-7 from zero. Use array to store information

1. Create an array; 2. Set the size of the array; 3. Assign values to array elements; 4. Modify the information in the array; 5. Create multidimensional array; 6. Array sorting. Program SpaceRemover: displays the input string and replaces all space characters with period characters. 1 package com.jsample; 2 3 public class SpaceRemover { 4 ...

Posted on Sun, 05 Apr 2020 19:51:22 -0700 by gammaster

What is the difference between 127.0.0.1 and localhost in connecting to mysql database

1, The difference between 127.0.0.1 and localhost in connecting mysql database 1. Connection of localhost to mysql database mysql -h localhost -uroot -p 2. The following is 127.0.0.1 connecting to mysql database mysql -h 127.0.0.1 root -p I don't know how you see the connection is different. Let me analyze ...

Posted on Sun, 05 Apr 2020 18:07:25 -0700 by elementaluk

Some small demo s in Vue Shop (background add-ons, foreground shopping carts, use of local storage)

demo. Background store, add a commodity <!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title></title> <!-- Introduce vue.js --> <script src="js/vue.js"></script> </head> <body> <div id="app"></div> ...

Posted on Sun, 05 Apr 2020 15:16:10 -0700 by calavera

Internet of Things Development Docking

Internet of Things Devices Camera Card reader Gateway lpr Wait and so on Communication protocol Frame Selection Device SDK Haikang camera, vehicle identification and other equipment Dahua's camera Red Gate Gate Principle: Use JNI or JNA technology of java to invoke c driver to realize docking of device data.Distinguish deployment platforms ...

Posted on Sun, 05 Apr 2020 13:48:41 -0700 by romilbm

Oracle's method of judging whether the table, column and primary key exist

When writing a program, the database structure will often change, so it is often necessary to write some database scripts, which need to be sent to the site for execution after the completion of writing. If there are already existing or repeated execution, some scripts will report errors, so it is necessary to judge whether they exist. Now I wi ...

Posted on Sun, 05 Apr 2020 12:38:05 -0700 by BrettCarr

Java8 handles Stream for the elegant posture of a collection

Preface In Java, collections and arrays are data structures that we often use and need to add, delete, change, check, aggregate, statistics, filter and so on.By contrast, this is true in relational databases, but collection and array processing was not very convenient until Java 8. However, this issue has been improved in Java 8, with the Jav ...

Posted on Sun, 05 Apr 2020 01:23:18 -0700 by mastermike707

A backup and restore of MySQL database in production environment

Background The company's production environment some application databases are deployed on the VMWare platform. In order to save costs, leaders are now considering migrating all data to the CAS platform living in KVM. The V2V migration was done before, but the efficiency is not high. It combines the time cost and other ...

Posted on Sat, 04 Apr 2020 16:31:01 -0700 by bob_marely

Clever use of aggregate $group in MongoDB

There is a set of data: { "campaign_id": "A", "campaign_name": "A", "subscriber_id": "123" }, { "campaign_id": "A", "campaign_name": "A", "subscriber_id": "123" }, { "campaign_id": "A", "campaign_name": "A", "subscriber_id": "456" } Group according to campaign ID and campaign name, a ...

Posted on Sat, 04 Apr 2020 10:14:04 -0700 by kaveman50