Yes, the archive is a roll up of effects. And it's mostly for efficiency, so that one does not have to go through all the millions of effects to get the state of a given point in time but can start from a known state and just add 10s of thousands of effects between archive times.
On 14 Jun 2011, at 21:28, McKinley <[email protected]> wrote: > Can you describe what you mean by archiving the state of the book each day? > It seems that you have a transactional system with your effects and an > archive at a point in time just seems like the range of effects by date. Is > an archive a roll-up of the effects for efficiency or backup? > > Cheers, > > McKinley > > On Tue, Jun 14, 2011 at 12:14 PM, Patrik Sundberg <[email protected] >> wrote: >> >>> Design question: >>> I have a Book. A book has Elements. To change what Elements are in a Book >>> there are Effects. An Effect adds or deletes an element from a Book (and >> has >>> other info). Everyday I archive the state of a Book so that I can easily >> get >>> the state of the Book (it's Elements) at a historical point in time. The >>> number of elements and which elements are in a Book vary from day to day >>> depending on the Effects taking place in the time period. >>> >>> So it's a bit like "Book contents archive of day X + 1 = Book contents >>> archive of day X + the Effects between X and X + 1" >>> >>> There's no need to represent the daily archives in any way, it's the >>> functionality of having historical snapshots that matter to me, so that >> one >>> can easily get the state of a Book at any point in time by finding the >>> closest archive point before the time and applying the Effects from that >>> archive timestamp and the point of interest. >> > _______________________________________________ > Neo4j mailing list > [email protected] > https://lists.neo4j.org/mailman/listinfo/user _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
