Experienced by thunder: written examination + computer + interview

It took a whole afternoon to return from the interview with thunder (I don't know what to say, but it takes almost two hours to wait). I feel that I can still perform the test and the computer, however, the answer to the Technical interview is not very good. Now I feel the difference between Internet companies and general software companies again. One of them is that Internet applications have high performance requirements, after talking for an hour, I felt like I was talking about performance issues. I have always been a weakness. Khan :(
I have carefully reviewed the questions of the entire interview process and recorded them. I hope you can give me more comments and discuss them.
I. Pen questions:
A) Java-based multiple-choice questions, which are relatively simple and omitted
B) Q &:
1) How does Ajax refresh data and its advantages?
2) What are the explanations and application scenarios of the facade model?
3) write 6 common Linux commands?
4) SQL statement, relatively simple
C) programming:
1) There are three thread IDs: A, B, and C. Please implement multi-line programming and print abcabc 10 times cyclically on the screen...
2) If there is a string "6sabcsssfs33", the fastest way to remove the character "ab3" is not to use the Java built-in string method (indeof, substring, replaceall, etc )?
Ii. Computer problems:
How can I count the number of letters, numbers, spaces, and rows in each file in a directory in Java?
3. Interview Questions:
1. How does JVM work? What is the difference between memory leakage and overflow? When will Memory leakage occur?
2. How can I use Java to implement dB storage with 0.1 billion records every day? How to design a database with hundreds of millions of records of data in MySQL?
3. Does MySQL support transactions? What are DB storage engines?
4. the MVC principle and advantages and disadvantages of the MVC model. If you want to design it, how can you modify the MVC?
5. Does hibernate support clusters? How to implement clusters?
6. How many concurrent users does Tomcat support?
7. How does MAP quickly find the key? What is the difference between map and set?
8. How to effectively merge two files: one is 0.1 billion pieces of basic user information, and the other is 50 million pieces of records of the user's daily watch series. Memory only 1 GB ???
9. In the 0.1 billion user records, how can I quickly query and count users who have watched more than 5 movies?
10. How does spring implement IOC and AOP and describe the implementation principles?
We look forward to your discussion and joint improvement. Thank you!