Getting started with MySQL (i)

Recently has been engaged in new staff training materials, MySQL training ppt I actually wrote more than 100 pages, I admire my own perseverance. Why not summarize these now, and slowly write them down to the blog for reference by beginners.

A relational database

The theory of relational database was put forward in the 70 's, by IBM researcher E.f.codd's paper.

The theoretical basis of the relational database can refer to the classic textbook "Introduction to Database System" compiled by Wang Shan and Shaman Xuan Munsu. I am not here to write, these theoretical too strong, as a quick start of the tutorial should not say these, but these theories are like martial arts in the easy to the same, after practicing what Kung Fu learn quickly.

The basic concept of two databases

Before playing Oracle added a group, found a lot of people wrote a long time PL/SQL, but still do not understand what is called the database, what is called an instance. I think, although do not know these can still write PL/SQL, but if you want to become a DBA, the basic concept must be clear, like the practice or the first horse, the next disk instability is always easy to fall.

Database: Refers to a set of files on a file system that behaves as a file with the suffix IDB in InnoDB.

Instance (instance): Refers to a set of processes/threads and memory on the operating system. If you execute ps-ef on a MySQL server | grep MySQL, you can see the process of MySQL.

Simply put, a database refers to a file, which refers to a process/thread and memory.

Usually we say that the database, a lot of time refers to the relational database management system (RDBMS), these concepts in rigorous documentation is to be strictly differentiated, but in peacetime communication, basically we have a conventional saying is no problem.

As for some other concepts of the database: tables, rows, columns, views, indexes, and so on, let's talk about them later.

Three MySQL Database overview

MySQL is the founder of the first Monty feel that other people's database is not good, write out their own services (Linux is the year Linus think Minix can only be used in teaching, in order to better learn the operating system written out), have to say these people cattle.

Later, he set up the MySQL AB Company, developed for commercial MySQL. After the company was the famous Sun acquisition, in the Sun period, MySQL launched 5.1 version, this version I used for a long time, is difficult to use, especially compared with the later 5.5, is simply too difficult to use.

In 2009, MySQL was acquired by Oracle along with Sun, Then Oracle launched the 5.5 version, I personally think this version is really a milestone version, when we upgraded from 5.1 to 5.5, the performance is really let me almost tears, especially more than 5.1 perfect partition table, is the same time I did the gospel of the Data Warehouse.

Later, we ushered in versions 5.6 and 5.7, which significantly increased concurrency and replication performance, especially the 5.7 parallel replication feature, which theoretically solves the persistent replication latency problem. I do feel that Oracle's leadership in the database sector is really not comparable to that of other companies.

Of course, open source software, especially good open source software, always has a branch. The biggest branch of MySQL is Percona server and mariadb. Percona server focused on performance improvements, its launch of the XTRADB engine is InnoDB's enhanced version, MARIADB will introduce more new features, especially MARIADB pioneered the parallel replication feature, really make official MySQL users jealous.

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Today we have written some basic concepts and the history of MySQL, which we also need to understand and know, and for a DBA there is no harm in the benefit of this knowledge. Today lying in writing, no mouse is not very convenient, so write a relatively brief.

Getting started with MySQL (i)