Re: Saving Images with Core Data (i.e., JPEG, TIFF, etc.)

FROM : mmalcolm crawford
DATE : Fri Apr 29 23:16:18 2005

On Apr 29, 2005, at 1:41 PM, Jim Correia wrote:

> On Apr 29, 2005, at 2:37 PM, mmalcolm crawford wrote:

>> For example, if a Person entity should have a 'photo' attribute, 
>> then create a Photo entity with just a single attribute -- the 
>> data -- and if you care a relationship back to the Person 
>> (typically modeling relationships in both directions is a Good 
>> Thing).  Then create a relationship from the Person to the Photo 
>> entity.  This will mean that photo data is only loaded from the 
>> persistent store if you actually use it.

> Is this true in general (or at least for SQLite stores)? 
> Relationships are loaded on demand, but attributes are loaded when 
> the object is? Is there any situation where attributes will be 
> lazily loaded, or is the concept of faulting only for entities? I'm 
> thinking of an example of an object that has
> ObjectEntity
>    name
>    date
>    comments
> It is being displayed in a table view, but the table view only has 
> columns for name and date, for example.
>

Faulting only applies to relationships (so in your example comments 
will be loaded along with the other attributes on fetch), and is only 
really relevant if you use a SQLite store since it can fetch data on 
an as-needed basis.  The other stores -- XML and binary -- both load 
the whole persistent store into memory when they're accessed.

mmalc