Mysql Foreign Key Example

Several guidelines on the establishment of the index: 1, a reasonable indexing can speed up the efficiency of data reading, but unreasonable indexing will slow down the database response speed. 2, the more the index, the slower the update data. 3, try to use the index when using MyIsam as an engine (because MySQL uses BTree to store indexes), not InnoDB. But MyISAM does not support Transcation. 4, when your program and database structure / SQL statement has been optimized to the extent that can not be optimized, and the program bottleneck can not be successfully resolved, then ...

StatefulSet problem created in K8s: Pod created using Deployment is stateless, when hanging in the Volume, if the Pod is hung, Replication Controller will run one to ensure availability, but because it is stateless, Pod Hanging up when the relationship with the previous Volume has been disconnected, the new Pod can not find the previous Pod. But for users, they are not aware of the underlying pods, but when the pods hang up ...

With the rise of internet web2.0 websites, the relational database has become a very hot new field, the development of the non relational database products is very rapid. 　　But the traditional relational database in dealing with web2.0 website, especially the super large-scale and high concurrent SNS type web2.0 pure dynamic website already appeared to be powerless, has exposed many insurmountable problems, for example: 1, high configured--to the database higher concurrent reads and writes the demand WEB2.0 website to be based on user personalized information to generate real-time dynamic ...

The advent of the 4G era, enterprise data faced with explosive growth, mobile TB; At the same time, human factors, software defects, uncontrollable natural disasters and other security problems occur frequently, how to make the enterprise data security and reliable, low-cost and efficient long-term preservation, has become an urgent concern for any enterprise. Fortunately, the cloud era accompanied by the 4G era, the core advantages of cloud computing: cost-effective, resource allocation, infrastructure flexibility, business smooth switching, bandwidth and storage unlimited expansion features. Multi-backup cloud backup, cloud recovery, cloud archiving and other special ...

There are a few things to explain about prismatic first. Their entrepreneurial team is small, consisting of just 4 computer scientists, three of them young Stanford and Dr. Berkeley. They are using wisdom to solve the problem of information overload, but these PhDs also act as programmers: developing Web sites, iOS programs, large data, and background programs for machine learning needs. The bright spot of the prismatic system architecture is to solve the problem of social media streaming in real time with machine learning. Because of the trade secret reason, he did not disclose their machine ...

In 2017, the double eleven refreshed the record again. The transaction created a peak of 325,000 pens/second and a peak payment of 256,000 pens/second. Such transactions and payment records will form a real-time order feed data stream, which will be imported into the active service system of the data operation platform.

What is a column-oriented open source distributed database HBase release time: 2012.04.16 14:41 Source: News and Author: HBase is a distributed, column-oriented open source database, developed by the Apache Foundation. Unlike a generic relational database, HBase is a database suitable for unstructured data storage. It is based on a column rather than a row based pattern. User stores data ...

(A) how to buy a virtual host, is to build a website novice one of the most frequently asked questions The following analysis will allow you to fully understand the current host market! The so-called virtual host (Virtual Host / Virtual Server), also known as virtual server or shared server, refers to the use of special hardware and software technology ,, in a server, the host can be virtual into 10, the same can be virtual into 100, and virtual host Each doubling of the number of placed ...

The intermediary transaction SEO diagnoses Taobao guest Cloud host technology Hall in understanding the Internet entrepreneurship Theory knowledge, began the field to carry out the actual operation of the website business. 　　In this chapter, we will explain in detail how to build a Web site that conforms to the user experience. First, the site's page planning and style design, the choice of the website programming language third, the choice of website database four, the Web site's hardware requirements and preparation of five, server hosting and maintenance six, server performance test seven, domain name query and registration eight, the actual combat exercise ...

Absrtact: With the rapid take-off of China's economy, the development of environmental pollution problems intensified, haze in all regions raging, PM2.5 index frequent "explosion", the daily life of the people caused great trouble, aroused public opinion's strong concern. The Government attaches great importance to and put PM2.5 monitoring work in the focus of environmental protection work. Cloud creates storage independent innovation PM2.5 cloud monitoring platform breaks the traditional research and development way, utilizes the innovative design idea, causes the environmental protection and the cloud computing high-end technology organic combination, the structure massive monitoring data storage, the processing platform, may reflect each region's air quality microcosmic, for the public ...