Opened http://code.google.com/p/googleappengine/issues/detail?id=786
regarding this issue.
On Oct 15, 12:25 am, Josh Heitzman <[EMAIL PROTECTED]> wrote:
> There are no indexes in index.yaml for these entity kinds and not very
> many of the properties are being changed at one time (no idea if that
> matters or not).
>
> If updating the implicit indexes is the majority of the cost of doing
> these updates, then I definitely agree that either--
> 1) an attribute for disabling the implicit indexing of properties
> should be added, or
> 2) native serialization needs to be provided as part of the runtime so
> we can quickly (de)serialize our data (from)into a blob.
>
> On Oct 15, 12:04 am, djidjadji <[EMAIL PROTECTED]> wrote:
>
> > For this entity at least 44 (10+1+2+15+1+15) index updates have to be done
> > in 16 different index tables (10+1+2+1+1+1). Every attribute has its
> > implicit index
> > and you get an implicit index for the 'product' of the property lists.
> > Not to mention the index tables mentioned in the index.yaml file that
> > this entity uses.
> > It can grow big when you have the ListProperties used in the
> > index.yaml file, 15 extra updates
> > for every mention of the string list property.
>
> > I'm sure not every property of an entity is used in a query to retrieve
> > objects.
> > To reduce the number of index updates it could be useful to have a
> > non-index version of every property type. Just like we have for the
> > StringProperty. The TextProperty does not have an index to be updated.
>
> > A possible syntax to tell AppEngine NOT to create and update an index for a
> > property would be to add an attribute to the Property constructor.
> > The default value of the attribute is True.
>
> > def MyModel(db.Model):
> > id = db.IntegerProperty(required=True)
> > num1 = db.IntegerProperty(need_index=False)
>
> > This would also help not to often hit the entity-index-update-limit
> > ('exploding' index).
>
> > Are the index updates counted in the mcycles used?
>
> > 2008/10/15 Josh Heitzman <[EMAIL PROTECTED]>:
>
> > > Regarding the first question, those mcycle numbers are from logs on
> > > GAE, not from local profiling. But if you mean are lots of people
> > > using, no. I was the only user with any data when I did the test.
>
> > > Regarding the second question, the entities are not what I would
> > > consider large. For example, one has 10 integer properties, 1 string
> > > property, 2 datetime properties, one string list property (15 strings
> > > with none more 30 characters long), and one int list property (only 1
> > > value at the moment).
>
> > > The entity group had 4 entities in it when I generated those numbers.
>
> > > There is no contention involved, as the data is user specific and I
> > > was the only user with data when I did the test.
>
> > > On Oct 14, 8:31 pm, "David Symonds" <[EMAIL PROTECTED]> wrote:
> > >> On Wed, Oct 15, 2008 at 1:50 PM, Josh Heitzman <[EMAIL PROTECTED]> wrote:
> > >> > Actually, I'm it take about 1500 mcycle to update one entity and then
> > >> > an about an additional 1000 mcycle per additional entity (each a
> > >> > different kind in this case) that is updated via the same db.put call.
>
> > >> Is this in production? What size is the entity? Is it in a large
> > >> entity group? How much contention do you think is involved?
>
> > >> Dave.
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