state TEXT     NOT NULL,
	    mid   INTEGER  NOT NULL  REFERENCES meta,
	    coff  INTEGER  NOT NULL,
	    clen  INTEGER  NOT NULL,

	    UNIQUE (fid, rev) -- The DTN is unique within the revision's file.
	}

	state writing optype {
	    oid   INTEGER  NOT NULL  PRIMARY KEY,
	    name  TEXT     NOT NULL,
	    UNIQUE(name)
	}
	state run {
	    INSERT INTO optype VALUES (-1,'delete');  -- The opcode names are the
	    INSERT INTO optype VALUES ( 0,'nothing'); -- fixed pieces, see myopstate
	    INSERT INTO optype VALUES ( 1,'add');     -- in file::rev. myopcode is
	    INSERT INTO optype VALUES ( 2,'change');  -- loaded from this.
	}

	state writing revisionbranchchildren {
	    -- The non-primary children of a revision, as reachable
	    -- through a branch symbol, are listed here. This is
	    -- needed by pass 5 to break internal dependencies in a
	    -- changeset.

	    rid   INTEGER  NOT NULL  REFERENCES revision,
	    brid  INTEGER  NOT NULL  REFERENCES revision,
	    UNIQUE(rid,brid)
	}

	state writing tag {
	    tid  INTEGER  NOT NULL  PRIMARY KEY AUTOINCREMENT,
	    fid  INTEGER  NOT NULL  REFERENCES file,     -- File the item belongs to
	    lod  INTEGER            REFERENCES symbol,   -- Line of development (NULL => Trunk)
	    sid  INTEGER  NOT NULL  REFERENCES symbol,   -- Symbol capturing the tag

	    rev  INTEGER  NOT NULL  REFERENCES revision  -- The revision being tagged.