Manifest Feature Matrix

Original spreadsheet

Num	Hash	Client On-Disk Manifest Format	Client Tree Manifest On-Desk	Tree Manifest in Exchange	Consequences: Read-delta works	Sane?	Use Case	Benefits	Interesting?
2	Current	V1	No	No	Yes	Yes	Existing Projects	Mostly read-delta	Obviously
6	Current	V2	No	No	No	?		Size: 30% smaller without general delta	?
8	Current	V2	Yes	No	No	Yes	Mozilla	Rebase et. al faster on client, old clients won’t break	?
9	Current	V2	Yes	Yes	No	Kind of	Exchange for modern client and server in above case
14	Tree	V2	No	No	No	Maybe	Small new project	Compact representation, less disk seeks
17	Tree	V2	Yes	Yes	No	Yes	Google	Narrow clones	Obviously

• Next step: analyze storange and perf of 14 and 17 on normal-size and mozilla-size repos to see if we should support 6 and 8.
• Concern: if exchange uses v1 format and disk uses v2, we have to do transformation between formats to apply deltas.
• If we can’t do old client compat, then we should only do row 2 and 17
• New delta encoding might also be worth considering, but completely orthogonal to this.