• Re recognize the count statement in MySQL


    In the operation of adding, deleting, modifying and querying database, the most frequently used is query operation. In all query operations, statistical quantity operations are often used. For row count in database, no matter mysql, Oracle or sqlserver, there is a function that can be used, that is count. For count, there are several questions […]

  • [soul torture] MySQL interview 100 questions


    Catalog Catalog Preface Index correlation Transactional correlation Table structure design Storage engine related Fragmented problem Reference articles Preface < font color = “red” > the main audience of this article is developers, so it does not involve MySQL service deployment and other operations, and there are many contents, so you are ready for patience and […]

  • The idea of integrating multi segment animation into one animation


    demand This is the requirement extracted from a project. The general idea is: through obtaining a series of point information of back-end personnel, simulate the action process of personnel in the front-end for a period of time. Our developers first thought of the idea is to get the information of the point list, each two […]

  • [typescript evolution history — 6] object extension operators and rest operators and keyof and lookup types


    By Marius SchulzTranslator: front-end witSource: Marius Schulz Hot wire: Alibaba cloud server 2019hi group promotion is in hot progress, new and old users can participate, 2-core 1g cloud server only needs79 yuan, 1-core 2G Hong Kong server only needs719 yuan /3, for more server configuration and price, please pay attention to: Hi group, or click […]

  • Use of truncate


    First,SQLSERVER TruncateUse When you no longer need the watch, use the drop; when you still want to keep the table, but want to delete all records, use the truncate; when you want to delete some records(always with a WHERE clause)delete. TruncateIt is a SQL syntax that can quickly empty all the data in the table. […]

  • From Devops to aiops, how can Ali achieve intelligent operation and maintenance?


    Abstract:Aiops is algorithmic IT operations. Aiops is a hot spot in the field of operation and maintenance. However, on the premise of meeting the business SLA, how to improve the efficiency and stability of the platform and reduce the cost of resources become the problems and challenges faced by aiops. background With the rapid development […]

  • Indexes


    Indexes I. Introduction to index A data structure in a database that is designed to help users quickly find data. Similar to the directory in a dictionary, can you find the storage location of data according to the directory when looking up the contents of the dictionary, and then get it directly. II. Function of […]

  • [video tutorial] implementation and thinking of message queue based on redis


    Use the list list of redis to implement the message queuing function. I believe everyone has heard of message queuing, but it may not be used in business. In the company project, there is a scenario where message queuing is used, so let’s talk about the process.There is a function of mass mailing in the […]

  • Research on the solution of front end anomaly monitoring


    Abstract:Abnormal monitoring is neither complicated nor simple Original text: Research on front end anomaly monitoring solution By frustigor Front end monitoring includes behavior monitoringAbnormal monitoring, performance monitoring, etc. This paper mainly discusses exception monitoring. For the front-end, it is in the same monitoring system as the back-end. The front-end has its own monitoring scheme and […]

  • Xiaobai’s growing diary: step by step, write a plug-in of carousel chart


    Recently, I read an article about interview “review my three failed interview experiences”. The author fell on the broadcasting chart three times. Sorry, so I also write a round robin chart.This time, it’s written in jQuery. Recently, I’ve been studying the writing method of jQuery plug-ins, so I’ve written in jQuery. Moreover, I found that […]

  • Secret! How to design a high accuracy embedded point frame of flutter


    background User behavior buried point is used to record a series of user behaviors during operation, and it is also the core data basis for business judgment. If it is missing or inaccurate, it will bring irrecoverable loss to the business. In the process of migrating business code from native to flutter, idle fish found […]

  • B tree and B+ tree


    Introduction Recently, I was reviewing the knowledge of database index,B+Tree is a very important data structure in database index. During the learning process, it is found thatBTree andB+The knowledge of data structure such as tree is very poor. Let’s review it. Study Indexes If there is no index, we need to traverse the entire table […]