[Prophesy] Database Structure and the Transport System

[Daniel Phillips]

On Wednesday 12 June 2002 17:43, I wrote:
>
>    text change table:
> 
>       object id, input version, output version, journal id, 
>       transform, untransform
> 
>    object create table:
> 
>       object id, input version, output version, journal id, name
> 
>    object move table:
> 
>       object id, input version, output version, journal id,
>       input name, output name

After reflecting a little, I realized that where I used 'input version, 
output version' representing a change between two version nodes, I should 
have used the arc between versions, giving a representation that is more 
compact and easier to search:

   text change table:

      object id, version arc, journal id, transform, untransform

   object create table:

      object id, version arc, journal id, name

   object move table:

      object id, version arc, journal id, input name, output name

which adds a new database entity, 'version arc', the directed arc from a 
version's parent to itself.  The primary version arc definitions can be 
folded into the version table:

   version table:

      version id, parent version, version arc id, tag

-- 
Daniel