Working in Java for Crud for three years, I didn’t expect to get an Ali R&D post with MySQL

Preface

MySQL has been ranked second in the past two years, and may surpass Oracle's plan to be promoted to the first place at any time, because MySQL's performance has been optimized, and the security mechanism has gradually matured, and more importantly, it is open source and free.

At present, most of the Internet's first choice is still MySQL, so as a developer, it is very necessary to master the use of MySQL, so how to achieve the degree of "proficient" in MySQL, it takes a lot of thought. So how to learn MySQL? Come and talk about it today.

The following introduces the three steps for me to learn MySQL. I completed MySQL in a week, so I won the R&D job offer from Ali smoothly.

In these three steps, a lot of documents are included, such as Xmind mind maps, study notes, practical documents, interview questions, etc., which are all free to share. Friends who need it, click here to download it directly.

The first step: sort out MySQL and list the structure diagram

No matter what knowledge and skills are learned, it is very important to learn to comb. For a knowledge combing, on the one hand, it can accelerate the memory, and on the other hand, it can make the whole of the knowledge points in the mind clearer and complete, so my first step in learning MySQL is Sort out MySQL.

For the sorting out of MySQL, I also specially compiled such a structure diagram, which contains the main core knowledge related to MySQL, which is really clear at a glance:

MySQL notes diagram (Xmind)

Step 2: From basics to actual combat, everything is done

1. Start from the basics, decrypt MySQL

2. 21 best practices for MySQL performance optimization

3. About MySQL, my personal small project

I wrote a simple shell script before, which can implement a simple MySQL Group Replication environment test and rapid deployment. It takes about 1 minute to quickly create multiple instance nodes. If you want to learn early MGR, it is recommended to try .

I have also manually tested it several times, and it works. I can't say it is tall, but it can basically meet the needs. Today, I took the time to improve it and deployed it in a brand-new environment. It was relatively smooth.

Let me briefly talk about this small project, and hope that everyone will work together to improve it gradually.

The screenshot on github is as follows:

If you want to quickly deploy MGR, here are some basic steps.

1\. 首先需要下载MySQL软件，配置/etc/hosts文件，下载二进制包都不需要什么安装了，直接解压放入指定的目录即可，比如/usr/local/mysql。目前最新的版本是官方的5.7.19

The third step: thoroughly understand the interview questions and successfully enter the big factory

1.24 must-master database interview questions

1. Why use auto-increment column as primary key
2. Why use data indexing can improve efficiency
3. The difference between B+ tree index and hash index
4. Advantages of hash index
5. Scenarios where hash index is not applicable
6. The difference between B tree and B+ tree
7. Why is B+ more suitable for file indexing and database indexing of operating systems in practical applications than B-tree?
8. MySQL Union Index
9. Under what circumstances should not build or build less index
10. What is a table partition?
11. The difference between table partitioning and sub-table
12. What are the benefits of table partitioning?
13. Limiting factors of partition table
14. How to judge whether MySQL currently supports partitioning?
15. What partition types does MySQL support?
16. Four isolation levels
17. About MVVC
18. In MVCC concurrency control, read operations can be divided into two categories
19. Advantages of row-level locking
20. Disadvantages of row-level locking
21. MySQL optimization
22. The difference between key and index
23. What are the differences between MyISAM and InnoDB in Mysql?
24. Notes on database table creation

2. MySQL database senior engineer job interview questions

3. BATJ Top-line Internet Frequently Asked MySQL Selected 55 Questions

Attached to Ali interview questions:

(Due to space issues, I will only list the questions of Ali interviewers in the following content, and I can only answer about half of them)

• Can you talk about why the B+ tree is better than the B tree in query?
• In addition to the above range query, can you tell some other differences?
• We just talked about B+ Tree, do you know what can be stored in the leaf nodes of B+ Tree?
• Is there a difference between clustered index and non-clustered index when querying data?
• You just mentioned that the primary key index query will only be checked once, while the non-primary key index needs to go back to the table for multiple queries. Is this the case in all cases? Will non-primary key indexes be queried multiple times?

Joint index, leftmost prefix matching

• What factors do you consider when creating an index? Have you ever used a joint index?
• When you create a joint index, how do you choose the order of multiple fields in the joint index?

Index push down, query optimization

• Do you know what optimizations have been made to indexes in MySQL 5.6?
• Have you created so many indexes, have they taken effect, or have your SQL statements used index queries, have you ever counted them?
• When troubleshooting, is there any way to know if there is an index query?
• So what happens when an index is clearly created, but the index is not passed when it is executed?
• Oh, let's ask so much about indexing knowledge for now. What is the transaction isolation level of your online data?

to sum up

"Free", "powerful", and "mature", these three points are enough to make MySQL stand at the top of the database field, proud of it. Therefore, being proficient in MySQL and enhancing self-competitiveness will surely shorten the distance with top-tier manufacturers.

In the above article, any MySQL-related materials involved can be shared with everyone for free. Friends who need these materials can get them by clicking here!