First off, that is a good talk. And I like it very much. But, it is still speaking of the workaround one can do to create a multi-part Model to query some part by __key__ and then grab the specific parent that contains the only props you want. You are still limited to partitioning your Models out into these specific parent, child relationships.. and then keeping track of those relationships and issuing queries based on said relationships.
The particular case I'm talking about is one where you have a Model with 100 properties that are all unindexed... so.. you only have an index on the key_name. You can define multiple Models that are related.. but you will still have to deal with an index on the key_name for each Model (I am assuming). I want to know if it would ever be possible to have a single Model.. with a single key_name with one index.. and then be able to selectively pull particular properties for that Model.. so.. if I want to update any three random properties, I issue a query that requests those properties.. updates them.. and puts() the entity back to the datastore.. only having to update those specific properties. In that situation, you wouldn't have the overhead of getting and putting properties that weren't going to be touched. Primarily, I'm wondering if there will ever be a way to avoid the overhead of pulling all properties for a Model when I only want to update a few of them. (The bandwidth used significantly impacts latency on the get() and the put() if the entities are fairly large) On Wed, Mar 31, 2010 at 10:09 PM, Raymond Ling <[email protected]>wrote: > I recommend this > video<http://www.youtube.com/watch?v=AgaL6NGpkB8&playnext_from=TL&videos=geh1T1kPh70> > (Youtube > Link: > http://www.youtube.com/watch?v=AgaL6NGpkB8&playnext_from=TL&videos=geh1T1kPh70 > ). > > The simple way to avoid loading big property one time is to design the > property as > owned-relationship<http://code.google.com/appengine/docs/java/datastore/relationships.html> > . > > To keep the consistency between the object in your memory (maybe use > memcache) and entity in datastore, it's better to load all properties one > time (except for big properties that may cause performance issue). > > On Thu, Apr 1, 2010 at 8:52 AM, Eli Jones <[email protected]> wrote: > >> it would be nice to get only a few properties for an entity.. and then >> update those entities and the .put() would only need to send the updated >> values over the wire > > > > > -- > Best Regards, > From Raymond Ling > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<google-appengine%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine?hl=en. > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
