This change adds a NOT NULL constraint to the created_at column in the segment table.
All occurrences of CreatedAt as a pointer are changed to non pointer version (metabase, segment loop, etc)
Change-Id: I3efd476ebd1edd3327b69c9223d9edc800e1cc52
It turns out that some DB methods are not
passing context to to lower levels even if have
context as a parameter.
Change-Id: I82f4fc1a47c362687a91364d85e4468057e53134
metabase has become a central concept and it's more suitable for it to
be directly nested under satellite rather than being part of metainfo.
metainfo is going to be the "endpoint" logic for handling requests.
Change-Id: I53770d6761ac1e9a1283b5aa68f471b21e784198
