[Zope] ZODB question, again

[Chris Withers]

Hi,

Wasn't it generally agreed that storing a counter in a ZODB was a bad idea 'cos of the high number
of refreshes, and hence the number of transactions stored in DB?

Basically, because of the undo/rollback capability of ZODB, the data.fs grows rapidly if you use it
to do counter-type things.

Or an I wrong?

Chris

Jonothan Farr wrote:
> 
> I would implement this whole thing as a Python product and avoid mucking around
> directly with the persistence machinery altogether. This would allow you to add
> a Counter object anywhere in the Zope tree.
> 
> import OFS, Persistence
> 
> class Counter(OFS.SimpleItem.Item, Persistence.Persistent):
> 
>     def __init__(self, id, title):
>         self.id = id
>         self.title = title
>         self.counters = {}
> 
>     def Count(self, name):
>         if not self.counters.has_key(name):
>             self.counters[name] = 0
>         v = self.counters[name] + 1
>         self.counters[name] = v
>         return v
> 
> manage_addCounterForm=HTMLFile('methodAdd', globals())
> 
> def manage_addCounter(self, id, title, REQUEST=None):
>     ob = Counter(id, title)
>     self._setObject(id, ob)
>     return self.manage_main(self, REQUEST)
> 
> Add a Counter call 'counter' to a folder, then call:
> 
> <dtml-var "counter.Count('chickens')">
> 
> -jfarr
> 
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