After class assignment for module 8 of phase 6 of the construction practice camp

design analysis

• One table for each message queue or one table for all messages ？

Consider if there is a message queue with a large number of messages , It may affect the performance of other message queues . therefore

One table per message queue

. The corresponding message queues are distinguished by table names .

• What to use as the primary key and index of the table ？

Since it's a message queue , The messages are sequential , Consider storing messages in a self incrementing column offset, At the same time, this column is used as the primary key .

Message query , Queries for time periods may be involved , And expired messages may need to be cleaned up . So design a column to store the time of message insertion , And add an index , Improve query efficiency .

• What information is required for the operation of messages ？

Push Insertion of message corresponding table , Messages cannot be modified after being queued , Therefore, it is not necessary to consider modifying records .

Pull Past messages can be kept in the table , Don't delete . Expired messages may need to be deleted in batches , You can query through the time column .

When something goes wrong , The source of the message and the format of the message can be useful information . To facilitate inspection in case of problems , Add one more metadata Columns store possible additional information . It can be used key、value Format store , Easy to extend other information .

Data sheet design

【 Table name 】

Corresponding message queue name

【 Field 】

Offset

, int, auto increment, unique index

Creation_Time

, date time, index

Message

, text

Metadata

, varchar