Page Comparison

•  MessageContent

(Immutable after creation)

• Primary key: ID
• Foreign key: CreatedBy (UserGroup)
• Foreign key: MessageBody (S3 File Handle ID)
• Self foreign key: InReplyTo (ID) (nullable)
• Etag
• CreatedOn

Backup via ID

Note:  Etag is required because MessageStatus is mutable.

Interface

• ID
• CreatedBy (principal ID)
• S3 File Handle ID
• inReplyTo (optional)
• CreatedOn

•  MessageToUser

(Immutable after creation)

• Foreign key: ID (MessageContent)
• Subject (nullable)

Secondary to MessageContent

Implements MessageContent

• Subject (string, optional)
• List of recipient IDs

•  MessageRecipient

(Immutable after creation)

• Foreign key: ID (MessageContent)
• Foreign key: Recipient ID (UserGroup)

Secondary to MessageContent

•  MessageStatus

• Foreign key: ID (MessageContent)
• Foreign key: Recipient ID (UserGroup)
• States: UNREAD, READ, ARCHIVED

Secondary to MessageContent

• ID
• Recipient
• State

•  Comment

(Immutable after creation)

• Foreign key: ID (MessageContent)
• Target type (Enum ObjectType)
• Target ID

Secondary to MessageContent

Implements MessageContent

• Target type
• Target ID

•  MessageInReplyToRoot

(Immutable after creation)

• Primary key: MessageContentID (FK to MessageContent)
• Foreign key: InReplyToRootID
  
  • Recursive foreign key to primary key

Secondary to MessageContent

•  Message votes

• Primary key: Message ID
• Up votes
• Down votes

• ID
• Up
• Down

•  MessageSettings

• Foreign key: User ID (UserGroup)
• Etag
• Blob of settings

• ID
• Notification levels
  • Update to an owned entity
  • Update to some favorite entity
  • Team
  • Message from user
  • Mail to everyone
  • Etc...
• Message receipt email (if more than one)
• Auto-mark mail as read if forwarded to email

•  MessageBundle

•  RecipientBundle