Entities are stored and retrieved as a single unit by the underlying datastore layer, so NDB, like all other APIs to it, retrieves and stores only complete entities. If you want to retrieve only parts, you'll have to split your model up into separate models, instead.
Note that entities are limited to 1MB each, too, so 4 1MB properties are not possible. -Nick On Wed, Mar 28, 2012 at 9:51 PM, Kaan Soral <[email protected]> wrote: > Lets say I have a model and it has numerous properties, with A,B,C,D > properties, all being 1MB's, so total size is roughly ~4MB's, and other > properties being insignificantly small. > > Is it possible to only fetch certain properties with entities? - For > example - as it is - if I fetched 100 entities, it would require 400MB's of > RAM [too much]. (I don't need A,B,C,D for that query result) > > I am trying to figure out If I should separate some properties to * > different_models* to ease querying, or does NDB solve this problem with > some built-in functions. (I have checked the documentation, not so deeply, > couldn't find anything). > I think discovering-learning functionalities like these are very important > while designing a system, so I am trying to learn NDB in depth, for this > reason any tips regarding NDB are also appreciated. (For example, what > problems does ndb solve that are unsolvable or unpractical using db ) > > Thanks in Advance > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/google-appengine/-/V_wp9a9MTAUJ. > 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. > -- Nick Johnson, Developer Programs Engineer, App Engine -- 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.
