Some ideas,
You may need to avoid using an entity group with that many records if you
are concerned about contention.
I would suggest generating key_names from your logical primary_key fields.
Also understand how you could leverage a list property style model for
filtering.
Your children can have the composite key as the key_name allowing you to
perform keys_only queries that you can pop out the parent key_name from.
What types of queries do you want to perform on your child entities?
On Tue, Oct 13, 2009 at 1:54 PM, Benjamin <bsaut...@gmail.com> wrote:
>
> anyone have a recomendation on the best way to store millions of child
> objects in data nuclues and maintain their relationship to a single
> persistant parent?
>
> On Oct 8, 10:21 am, Benjamin <bsaut...@gmail.com> wrote:
> > sorry for the dup post
> >
> > I'm trying to find guidence on managing one to many releationships in
> > the data store when the number of children the parent will have will
> > be huge - 32000 children added to a parent a day
> >
> > a simple parent class:
> >
> > @PersistenceCapable(identityType = IdentityType.APPLICATION,
> > detachable = "false")
> > public class Parent {
> >
> > @Persistent(mappedBy = "parent")
> > private ArrayList<Child> points;
> >
> > a simple child class
> >
> > public class Child {
> > @Persistent
> > private Parent parent;
> >
> > and the parent arraylist is getting many children added to it and the
> > datastore updated. I'm afraid that whenever i query for the parent
> > object i'm going to get all of the children which i would never need
> > to do - i would want to get parts of the children collection and i do
> > want to maintain the relationship so parent deletes are cascaded.
> >
> > How do you query the datastore and get a parent without the children -
> > it looks like the child collection gets populated by default when you
> > just do a query like this:
> >
> > Query q = pm.newQuery(Parent.class, "key== k");
> > k.declareParameters("Long u");
> > List<Parent> result;
> > result = (List<Parent>) q.execute(key);
> >
> > with a huge number of children, wouldn't this query be very slow?
> >
>
--
Kevin Pierce
Software Architect
VendAsta Technologies Inc.
kpie...@vendasta.com
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