Re: More on identifiers
Date: Sat, 06 Jun 2009 04:19:43 GMT
On Fri, 05 Jun 2009 14:52:27 +1000, David BL <davidbl_at_iinet.net.au> wrote:
> Due to the projection, all the abstract identifiers have disappeared
> from every relation. In a way, it's like seeing a database within a
> database! The value of the "inner" database records all the facts in
> the /context/ of just one of the items, and therefore has no need for
> abstract identifiers to glue things together.
I may have misunderstood, but haven't you just moved the 'problem'? That is, each abstract identifier that you want to get rid of ends up with 'its own database'. Two database values that came from entities that differed only by their abstract identifier will not be distinguishable. So to distinguish between them, the abstract identifiers and up being arbitary names of databases.
Joe Received on Sat Jun 06 2009 - 06:19:43 CEST