[ZODB-Dev] ZODB and ORBit-Python problems

Jim Fulton jim@digicool.com
Sat, 19 May 2001 11:00:06 -0400


Christian Robottom Reis wrote:
> 
> On Fri, 18 May 2001, Jim Fulton wrote:
> 
> > Of course, if you want to load all your data in memory at once, you don't need
> > ZODB.  Where ZODB tries to add value is by loading and keeping just the data
> > you need when you need it.
> 
> This makes perfect sense. However, at times, an application has to do
> things both ways: use objects interactively with it's interface, loading
> and using objects as needed; and generate summaries from information
> contained in a series of objects.

I don't think I understand you. I don't see what the above had to do with loading
*all* the objects from the database.

> For the second case, I've been thinking over two solution; the first is
> moving data to a summary store periodically, already summarized; the other
> is providing a mapping to a RDBMS for just the data you need summarized
> and moving data over it periodically too.
> 
> The second solution seems sane enough, since it permits different
> summaries based on data, and the mapping part can be straighforward if you
> don't want to map the whole world, too.

I have to say that I really have no idea what problem you are trying
to solve, so I'm not going to begin to think about whether the solution
you outline makes sense. I never want to load all the objects in the 
database.  I have, rarely been interested in getting some statistics on
overall object distributions, but never have I wanted this badly enough
to bother with it.

I will note that there are mechanisms for iterating over a storage
(see for example the FileStorage interator machinery and
the use of the iterator machinery in BaseStorage) that could
be used to answer some basic questions about object class and
size distributions.

Jim


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