1. Which operation can be significantly improved by database indexing? A

A SELECT B INSERT INTO… VALUES… C UPDATE D DELETE

2. Databases: Which of the following locking methods provides the best parallel access performance? D

Column A is locked, table B is locked, block C is locked, row D is locked

3. What happens when the WHERE clause is omitted from the DELETE statement? B

A DELETE statement will fail because there are no records to DELETE B DELETE statement will DELETE all records from the table C DELETE statement will prompt the user to enter the DELETE standard D DELETE statement will fail because of syntax errors

4. What network layer protocol does Raceroute generally use? D

A vrrp

B udp

C arp

D icmp

5. Which LSA of OSPF can be propagated only in the local area? A

A 2

B 3

C 5

D 7

6. Which of the following signals cannot be caught in Linux? B

A SIGHUP

B SIGKILL

C SIGQUIT

D SIGUSR1

7. In Linux, how do I check which process is occupying a port? B

A netstat – an | grep port B netstat TNLP | grep port C iostat – an | grep port D iostat – DXT | grep port number

8. How to remove duplicate elements from a list? B

List A cannot be de-duplicated list B first converts list to A de-duplicated set, then converts list C first converts list to A de-duplicated tuple, and then lists D without duplication

What is the difference between a List and a Tuple in Python? A

A lists are mutable, tuples are immutable B no difference C limits are different D lists can be iterated, tuples cannot be iterated

10. What is the correct statement about inheritance of Python classes? C

A A Python class cannot inherit B A Python class can inherit but C can have more than one parent D can have only one parent

11. Which of the following statements about ports is true? A B C D

A FTP uses TCP port 20 B FTP uses TCP port 21 C DNS uses TCP port 53 D DNS uses UDP port 53

12. What are the differences between GET and POST in HTTP? A b C D

B GET request parameters are placed in the URL. C GET is only used for query requests and cannot be used to request data. D GET should not handle requests for sensitive data

13. A simple web site might consist of three parts: a Web server (which provides web pages and HTTP services), a backend server (such as a Java daemon, which does calculations), and a mysql database server (which stores user data). However, we know that such a website is also very vulnerable, any one of the above three server problems (server problems, or server network problems, or the above running procedures), will lead to website access. Obviously, this is not in line with meituan Dianping’s service promise to users. Now, if you are the technical manager of your company, what enhancements or improvements do you think you would make in each of these areas to help improve the usability of your website? (List as many as possible)

14. In what ways is a hash function good or bad? How many common hash functions are there?

1. High efficiency, CPU saving, and concurrency improvement. As an intermediate layer, it is necessary to efficiently compute hash 2 based on keys. 3. Save space as much as possible. For example, if we want to store the result in a database and index the hash result, we want the column to be as small as possible to save data storage space. Especially when creating an index in a database, the smaller the field to be indexed, the better. It is important to evenly distribute keys, especially when multiple nodes are deployed, to avoid load balancing. 5. During rehash, minimize key redistribution to avoid heavy impact on the back-end

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