There's no significant difference. Check out this article about how things
are stored:

http://code.google.com/appengine/articles/storage_breakdown.html

<http://code.google.com/appengine/articles/storage_breakdown.html>The value
doesn't change how we query our indexes for values with None or -1.

On Wed, Feb 24, 2010 at 9:45 PM, Jairo Vasquez <[email protected]>wrote:

> Yes it is and I can search using property=None but my question was
> more about what is more efficient, filter with property=None or use a
> value like '-1' and filter property='-1'
>
> Thanks for the replies
>
> On Feb 24, 9:23 pm, "Ikai L (Google)" <[email protected]> wrote:
> > I believe so. What have you observed when saving your models?
> >
> > On Wed, Feb 24, 2010 at 12:55 PM, Jairo Vasquez <[email protected]
> >wrote:
> >
> >
> >
> >
> >
> > > Thanks Ikai,
> >
> > > But what is the difference between empty values and None when you
> > > define a Model in GAE? Because you just define a property without a
> > > default value and when you create an instance of that entity, the
> > > value will be None isn't it?
> >
> > > On Feb 24, 1:36 pm, "Ikai L (Google)" <[email protected]> wrote:
> > > > That *should* create an index. We index null values, but we don't
> index
> > > > empty values. That is, if you have an entity:
> >
> > > > Animal {
> > > >     String name;
> > > >     int age;
> >
> > > > }
> >
> > > > And create 100 entities, then add:
> >
> > > > Animal {
> > > >    String name;
> > > >    int age;
> > > >    String nickname;
> >
> > > > }
> >
> > > > The 100 entities that were created will have an EMPTY nickname and
> will
> > > not
> > > > be queryable by this attribute, but Animals created after the change
> that
> > > > populate this field will be indexable.
> >
> > > > On Tue, Feb 23, 2010 at 9:58 PM, Jairo Vasquez Moreno <
> >
> > > > [email protected]> wrote:
> > > > > Hi Nick,
> >
> > > > > I know every write to Datastore creates an index entry for each
> > > indexable
> > > > > value. But when a value is not set (None) will an index entry be
> > > created?
> >
> > > > > My doubt is, is it better to let a property None and then filter by
> > > > > property=None or set the with something e.g property="-1" and then
> > > filter by
> > > > > property="-1". Because I'm leaving a property as None and then
> doing
> > > some
> > > > > stuff with those entity with None but this is generating more
> > > > > DeadLineExcedeed errors as expected (even decreasing the number of
> > > entities
> > > > > to fetch) so I think maybe the filter is getting to much time and I
> > > don't
> > > > > know what else could be.
> >
> > > > > Thanks in advance.
> >
> > > > > --
> > > > > Jairo Vasquez Moreno
> > > > > Mentez Developer
> > > > >www.mentez.com
> > > > > Medellin - Colombia
> >
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> > > > --
> > > > Ikai Lan
> > > > Developer Programs Engineer, Google App Enginehttp://
> > > googleappengine.blogspot.com|http://twitter.com/app_engine
> >
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> > --
> > Ikai Lan
> > Developer Programs Engineer, Google App Enginehttp://
> googleappengine.blogspot.com|http://twitter.com/app_engine
>
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>


-- 
Ikai Lan
Developer Programs Engineer, Google App Engine
http://googleappengine.blogspot.com | http://twitter.com/app_engine

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