On Apr 30, 2009, at 5:01 PM, Christian Theune wrote: > Hi, > > On Tue, 2009-04-28 at 13:54 -0400, Jim Fulton wrote: >> Thanks again! >> >> (Note to everyone else, Shane and I discussed this on IRC, along with >> another alternative that I'll mention below.) >> >> I like version 2 better than version 1. I'd be inclined to simplify >> and it and skip the configuration flag and simply publish an event >> any >> time we see a cross-database reference when saving an object. >> >> Here's proposed solution 3. :) >> >> - We add a flag to disable new cross-database references unless they >> are explicitly registered. >> - We add a connection method to register a reference: >> >> def registerCrossDatabaseReference(from_, to): >> "Register a new cross-database reference from from_ to >> to." >> >> - We arrange that connections can recognize old cross-database >> references. >> >> If someone accidentally creates a new reference and the flag is set, >> then transaction will be aborted. >> >> An interim step, if we're in a hurry to get 3.9 out, is to simply add >> the flag. This would disallow cross-database references in new >> applications. These applications could still support multiple >> databases by providing application-level traversal across databases. > > I think I'm reading something incorrectly: is there an emphasis on > "*new* applications"?
No > The flag would disallow the creation of > cross-database references for a given DB -- independent of whether the > app is new or old, right? Right > Only depending on whether the application uses > a ZODB that has the feature and has it enabled. Right? This is not a sentence. :) The flag would disable implicit references (new or old). When an object is being saved, if it has implicit cross-references, the save will fail. The second and third bullets above provide a way to make explicit references. I've implemented the first bullet. There's a question of whether I need to implement the second 2 bullets for ZODB 3.9. Jim -- Jim Fulton Zope Corporation _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev