[ZODB-Dev] [Enhancement Proposal] Garanteed lifetime for volatile variables

[Jim Fulton]

Chris Withers wrote:
> Jim Fulton wrote:
>> - I wonder if an argument could be made than we shouldn't
>>   implicitly deactivate an object that has been accessed in a
>>   a transaction while the transaction is still running.
> 
> Would this prevent ZODB from ever promising not to use more than a 
> certain amount of memory?

Yes, and non-necessarily.  :)

The only way that ZODB could keep such a promise would be to
disallow loading new objects, generating errors under some circumstances.

Certainly, as Dieter pointed out, this would make it harder to
remove objects from memory.

> The biggest zodb-related performance problems I've seen are when a 
> scripter writes code that drags way more objects into memory than any 
> sane script should. The creates a HUGE python process which never 
> releases the memory back to the os (I believe that may be fixed in 
> Python 2.5?) which causes all kinds of performance problems...
> 
> It should be possible to prevent scripters shooting themselves in the foot!

Sorry, that's impossible.

Jim

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