@
@ -- A record of phantoms.  A phantom is a record for which we know the
@ -- UUID but we do not (yet) know the file content.
@ --
@ CREATE TABLE phantom(
@   rid INTEGER PRIMARY KEY         -- Record ID of the phantom
@ );
@
@ -- A record of orphaned delta-manifests.  An orphan is a delta-manifest
@ -- for which we have content, but its baseline-manifest is a phantom.
@ -- We have to track all orphan maniftests so that when the baseline arrives,
@ -- we know to process the orphaned deltas.
@ CREATE TABLE orphan(
@   rid INTEGER PRIMARY KEY,        -- Delta manifest with a phantom baseline
@   baseline INTEGER                -- Phantom baseline of this orphan
@ );
@ CREATE INDEX orphan_baseline ON orphan(baseline);
@
@ -- Unclustered records.  An unclustered record is a record (including
@ -- a cluster records themselves) that is not mentioned by some other
@ -- cluster.
@ --
@ -- Phantoms are usually included in the unclustered table.  A new cluster
@ -- will never be created that contains a phantom.  But another repository