RSS Feed for Vertica Forum
https://forum.vertica.com/discussions/feed.rss is the RSS feed to Recent Discussions. Recent Discussions shows you the list of discussions in chronological order based on last activity date. When a discussion appears here it's either because it's brand-spanking-new with no comments, or it is older and someone else has responded to it. Pulling in all comments that are left for these discussions could easily result in thousands of comments being pulled into the RSS reader at once. If you see a post appear in your RSS Reader that you've seen before, it's because there's been another comment made, and you can choose to follow the link out from the reader to the real-live post and read the discussion in context with its slew of comments attached.
Alternatively, you can get an email for every comment posted using Profile > Edit Profile > Notification Settings.
For info about using Vanilla Forums with Slack, see https://blog.vanillaforums.com/help/using-forum-rss-feeds-in-a-slack-channel/.