RE: [Zope-dev] Persistence ( was Thread Safe Counting )
Jon Franz <[EMAIL PROTECTED]> wrote > Ah! this makes more sense, the idea of persistent properties even > fits with this idea, though a true write-in-place property might be > even better for some applications ;) Two things: * Don't count on storing the hit counter as a separate, "persistence aware" object (i.e., with its own pickle jar) to avoid bloating your Data.fs. Hit counters are by definition high volume, and the space overhead for managing undoable persistence is higher than you might think. * Write-in-place will never be supported by packable/undoable storages (logically impossible); some "packless" storages are already in play (maybe even near release), so the semantics you want may be (soon) readily available by mounting a separate storage. Tres. -- === Tres Seaver[EMAIL PROTECTED] Digital Creations "Zope Dealers" http://www.zope.org ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
RE: [Zope-dev] Persistence ( was Thread Safe Counting )
Ah! this makes more sense, the idea of persistent properties even fits with this idea, though a true write-in-place property might be even better for some applications ;) Next time I'll read the whole thread and not the last post in it! > -Original Message- > From: Chris Withers [mailto:[EMAIL PROTECTED]] > Sent: Sunday, February 11, 2001 1:05 PM > To: Jon Franz > Cc: '[EMAIL PROTECTED]' > Subject: Re: [Zope-dev] Persistence ( was Thread Safe Counting ) > > > Jon Franz wrote: > > > > So subclassing persistent will avoid changes to the object > being stored and > > roll-backable in the ZODB? > > NO! read the posting again... Subclassing from persistent is > HOW you make things > live in the ZODB. However, objects that subclass Persistent > get their own pickle > jar, and so only make the ZODB grow by the size of themselves > and their > attributes each time they change. In my counter's case, > that's not a lot :-) > > > Now, if only we could get this sort of > > store-in-place functionality on a more fine-grained level (like on > > individual > > properties) - we could avoid a lot of coding to prevent > ZODB bloat with > > simple > > features.. Ie, if I were to make a 'persistent porperty' on > a DTML method, > > I could store counter information in that property without worry > > of ZODB bloat. > > I wouldn't be surprised if something like this happens at > some stage ;-) > > cheers, > > Chris > ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] Persistence ( was Thread Safe Counting )
Jon Franz wrote: > > So subclassing persistent will avoid changes to the object being stored and > roll-backable in the ZODB? NO! read the posting again... Subclassing from persistent is HOW you make things live in the ZODB. However, objects that subclass Persistent get their own pickle jar, and so only make the ZODB grow by the size of themselves and their attributes each time they change. In my counter's case, that's not a lot :-) > Now, if only we could get this sort of > store-in-place functionality on a more fine-grained level (like on > individual > properties) - we could avoid a lot of coding to prevent ZODB bloat with > simple > features.. Ie, if I were to make a 'persistent porperty' on a DTML method, > I could store counter information in that property without worry > of ZODB bloat. I wouldn't be surprised if something like this happens at some stage ;-) cheers, Chris ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
[Zope-dev] Persistence ( was Thread Safe Counting )
>> Morten's product stores the counter's >> value in a file on the filesystem, and so it doesn't cause the >> Data.fs to grow. > >Hmmm, well, my counter above wouldn't cause the data.fs to grow all that much, >since it subclasses Persistent and so gets its own pickle jar. > >cheers, > >Chris So subclassing persistent will avoid changes to the object being stored and roll-backable in the ZODB? Nice! Now, if only we could get this sort of store-in-place functionality on a more fine-grained level (like on individual properties) - we could avoid a lot of coding to prevent ZODB bloat with simple features.. Ie, if I were to make a 'persistent porperty' on a DTML method, I could store counter information in that property without worry of ZODB bloat. Hrm... *Jon staes into the distance wondering how much will break if he tries to implement a 'persistent' flag for properties* ~Jon ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
