spair at acm.org
Sun Aug 4 02:55:16 UTC 2002
Right...you have a couple of choice under these conditions:
A) Never permanently keep references to *any* persistent object...you
just access them by travarsing the persistent objects from the root
whenever you need to do something (stubbing everything in along the
way)...this might severely impact performance for certain apps because
every operation (think about an http request that is very frequently
called and that needs to get at some persistent objects...on ever http
request, you'll be fetching the root, then another object, then another,
until you get to the one you want). This is in a sense a cache strategy
that flushes *everything* immediately after it is used.
B) Keep persistent objects around that your app needs and risk faulting
in the entire db over time...this might not be an issue for applications
that don't run for long periods of time. This is essentially a cache
strategy that never flushes anything.
C) Implement your own caching scheme in your application (i.e. hold the
objects you are frequently using, but re-stub those that haven't been
used in a while).
All of these are cache management strategies.
> -----Original Message-----
> From: squeak-dev-admin at lists.squeakfoundation.org
> [mailto:squeak-dev-admin at lists.squeakfoundation.org] On
> Behalf Of Chris Muller
> Sent: Saturday, August 03, 2002 7:25 PM
> To: Squeak List
> Subject: Re: Magma design
> Stephen Pair wrote:
> ...the issue I see is that you can
> eventually get the whole database in memory (if your
> application runs long enough and works with enough of your dataset).
> No way dude! :-) Magma doesn't keep around any objects your
> program doesn't,
> *including* the root.
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