Dirty entity identification.

[Chris Shoemaker]

On Fri, Jul 22, 2005 at 10:23:33AM -0400, Derek Atkins wrote:
> Chris Shoemaker <c.shoemaker at cox.net> writes:
> 
> >> So the Account can only iterate over all it's splits and the Trans can only 
> >> iterate over all it's splits. Neither can identify a single split without 
> >> iteration. The hierarchy is not symmetrical neither is does it accord with 
> >> the tree model.
> >
> > I'm not sure it's all that complicated.  I think split cascades to
> > account, account cascades to book, and transactions can just cascade
> > to book, too.  With a few other things cascading up to book, I think
> > David would have what he wants.
> 
> What about Customers?  Invoices?  PriceDB Entries?  SXes?  Commodities?

Most branches are probably shallow.  If an object isn't contained by
anthing other than the book, then it's contained by the book.

> 
> There are lots of objects in the database that can be touched/modified
> that don't fall into the CoA tree structure.  Please don't limit
> yourself to thinking only about the CoA.
> 
> Honestly, I really don't think we don't need to know which objects are
> dirty.  I just don't see that as a requirement for anything we're
> doing at the moment, or in the future.  Besides, if we wanted to, we
> could just create a second HashTable in each Collection and put a
> reference to each committed/changed object into that second HashTable.
> It means we'd effectively need twice the amount of metadata storage,
> but I don't think those hash tables really take up a lot of space.
> 
> However, I still don't think we need that at the moment.

I agree that we don't currently (and probably never will) need to
track a list of *references* to dirty objects.  But, a boolean flag
that propagates back to book might be more useful.  And if we ever
*do* need to find the dirty instances, the boolean flag makes the
search much easier.

-chris


> 
> -derek
> -- 
>        Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
>        Member, MIT Student Information Processing Board  (SIPB)
>        URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
>        warlord at MIT.EDU                        PGP key available