[Zope] When Does ODB Run Out of Steam?

Roger Erens r.erens@eurosys.nl
Wed, 5 Sep 2001 11:13:06 +0200


# -----Oorspronkelijk bericht-----
# Van: Dieter Maurer [mailto:dieter@handshake.de]
# Dan Shafer writes:
#  > I have a client who has an application he wants me to build. I'm 
#  > going to use Zope. The question is whether I should use 
# the built-in 
#  > object database or an SQL database. I _vastlly_ prefer the 
# former; I 
#  > tend to think in objects.
#  > 
#  > Each client object in the system has potentially 350 separate 
#  > properties. These are entered, reported, and managed 
# through a series 
#  > of about 12 forms. Some of the forms can be used by the client to 
#  > create multiple entries of the same type.
# This may make for quite large objects...
# 
# Note, that properties are not persistent objects but belong
# to the direct content of their object.
# When you reference the object, the complete direct
# content is swapped in (if it is not already in the cache).
# Depending on the size of your properties, this may become
# a performance problem.
# 
# When you use a relational database, you may probably access
# only the properties actually used for the current
# application.
# 
# 
# Dieter

Surely(?) not all his objects will use every single property out of 350.
Since an object's attribute only springs into existence when they are
actually assigned to (section 9.3.3 of the Python tutorial), the average
object might not need get quite so large.

Roger