Description

Description:

Document that $out in $lookup is banned. Mention this in release notes for 4.2, as $out in $lookup is allowed in 4.0.

Engineering Ticket Description:

After debating this point during the design of the new $out features, we eventually decided to disallow this combination in any scenario, not just for views as was done in SERVER-35419 + SERVER-34902.

Scope of changes

• $lookup
• $out
• Modify the blurb for views restrictions Actually, it doesn't read well in the extract and is kind of distracting. The blurb already covers it, so will skip for now.
• Restrictions page Actually, we don't quite do this for specific agg operators (so to prevent confusion as to this is the only limitation, will skip for now)
• 4.2 compatibility
• Check downgrade Actually, since we already cover for views and its definition, we should be good since there shouldn't have other persisted features that incorporate lookup.

Impact to Other Docs

MVP (Work and Date)

Resources (Scope or Design Docs, Invision, etc.)