Alias Messages

Messages managing collection aliases. All are CChannel-only broadcasts serialized at the database level.

All broadcast messages implicitly carry SharedCluster via the Broadcaster.

Message	Dispatch	ExclusiveRequired	ResourceKey
AlterAlias	Broadcast: CChannel	No	ExclusiveDBName
DropAlias	Broadcast: CChannel	No	ExclusiveDBName

• AlterAlias: Creates or alters an alias to point to a collection.
• DropAlias: Drops an alias.

Key Invariants

• All alias operations are serialized via ExclusiveDBName.
• ExclusiveDBName conflicts with SharedDBName (used by collection-level DDL), so alias operations block all collection DDL in the same database.
• CreateAlias uses the AlterAlias message type internally.