When you use SQL statements to access tables in a database without an index configured, a full table scan will be performed. If a table contains a large amount of data, this kind of scan will access a large amount of data and consume a lot of the database's resources. Which of the following options are best practices when creating database indexes? (Number of correct answers: 3)

• A.table should not contain more than 6 indexed fields.
• B.Applies indices to fields that contain many records.
• C.Adhere to the rightmost prefix principle when using composite indexes.
• D.Add an index to a field that is frequently queried but does not frequently perform add, delete, or modify operations.
• E.Apply indexing to fields of fixed length (preferably not long fields).

Comment: *

Name: *

Email: *

Verification: *

A certain project of Enterprise A (called Project-X) moves to the cloud and will need to use a variety of s Alibaba Cloud resources, such as ECS instances, RDS instances, SLB instances, and OSS storage space. There are multiple employees on the project who need to operate these cloud resources. Because each employee has different job responsibilities and requires different permissions, what is the WRONG approach to resource management?

• A.Create RAM users each employee, and set login passwords or create AccessKey credentials as needed
• B.When creating RAM for users, give each user both web console AND AccessKey credentials: there is no need to keep these separate
• C.Use system policies to bind reasonable permissions policies to users or user groups, and customize policies for more fine-grained control
• D.When there are multiple RAM users under a cloud account, create user groups to classify and authorize RAM users with the same responsibilities

Comment: *

Name: *

Email: *

Verification: *

What are the required parameters for the Python SDK to create a client to access Alibaba Cloud's API?
(Number of correct answers: 3)

• A.access.keyjd
• B.access.key.secret
• C.regionjd
• D.zone jd
• E.vpcjd

Comment: *

Name: *

Email: *

Verification: *

You can create an event notification rule in Message Service and push notifications to the specified consumer in the form of messages, to receive events from specified Alibaba Cloud resources. Which of the following options are correct statements about the Message Service (MS) service? (Number of correct answers: 2)

• A.Message Service provides synchronous notifications to ensure the consistency between the message acknowledgment and event processing.
• B.The event notification message is retained within the valid time. When you fail to receive an event message, the event notification message is retried based on the specified retry policy.
• C.The consumer type of the event notification message can be HTTP Server, Queue, or Topic.
• D.Event Notifications can cross regions.

Comment: *

Name: *

Email: *

Verification: *

If a user finds that the Content Delivery Network (CDN) cache hit rate is low, what could be the reason?
(Number of correct answers: 3)

• A.The origin site has a large number of dynamic resources.
• B.HTTP Header settings may cause cache misses.
• C.When the website has low traffic, the CDN will receive fewer requests and this will result in a lower cache hit rate.
• D.Insufficient bandwidth was selected when enabling the CDN service, causing the service capacity reach its limit too early.
• E.Cache configuration is inappropriate (ex. overly short Cache Expiry Time for popular files).

Comment: *

Name: *

Email: *

Verification: *