Chatter posts are stored using a series of relationships that follow a common pattern, illustrated in Figure 12.1. Starting from the right of the diagram, a Feed object, suffixed with the word Feed, contains Chatter posts. Feed objects exist for each Chatter-enabled parent object type. The parent object is on the left, and the line between them indicates that a single parent record can have zero to many posts.
Feed objects are unusual for Force.com in that they are read-only. To insert or delete Chatter posts, you must use the generic
FeedItem object, discussed later in this chapter. ...