Yeah, you might want to break it up in that case. If you don't use bigChunkOfJson frequently, put it in a different object that you can generate the key for on the fly (so you can use a get by key instead of needing to use a query).
-- Ikai Lan Developer Programs Engineer, Google App Engine Blogger: http://googleappengine.blogspot.com Reddit: http://www.reddit.com/r/appengine Twitter: http://twitter.com/app_engine On Thu, Nov 11, 2010 at 1:55 PM, Mark <mar...@gmail.com> wrote: > Thanks Ikai. I have an entity that has a bunch of Text properties, > they can each be quite large. I wanted to avoid loading them if > they're not going to be used for a specific query. For example, I have > a list of GameRoom objects: > > class GameRoom { > String gamename; > String mapname; > > Text bigChunkOfJson1; > Text bigChunkOfJson2; > Text bigChunkOfJson3; > } > > If a user wants to get a listing of games my service is hosting, it's > probably not wise for me to deserialize each "bigChunkOfJson" property > to give them a simple game listing. Only if they join a game do I need > to touch those Text properties. I read the Relationships page again > and it seems that child objects are lazy loaded: > > "Child objects are loaded from the datastore when they are accessed > for the first time. If you do not access the child object on a parent > object, the entity for the child object is never loaded. If you want > to load the child, you can either "touch" it before closing the > PersistenceManager (e.g. by calling getContactInfo() in the above > example) or explicitly add the child field to the default fetch group > so it's retrieved and loaded with the parent" > > So I figure I could split my class up like: > > class Game { > String gamename; > String mapname; > > MoreInfo more; > } > > So if I query for Game instances, so long as I don't access the > MoreInfo object, that data won't be fetched (if I understand > correctly). Then I can put all my Text objects in that class, > > Thanks > > http://code.google.com/appengine/docs/java/datastore/relationships.html > > > > On Nov 11, 3:56 pm, "Ikai Lan (Google)" > <ikai.l+gro...@google.com<ikai.l%2bgro...@google.com> > > > wrote: > > Text properties were never actually lazy loaded. We only lazy loaded them > to > > match the JDO/JPA spec. In practice, the entire entity was being read and > we > > just weren't populating the entity. > > > > Try running AppStats - though I suspect the deserialization shouldn't be > > *that* slow. > > > > -- > > Ikai Lan > > Developer Programs Engineer, Google App Engine > > Blogger:http://googleappengine.blogspot.com > > Reddit:http://www.reddit.com/r/appengine > > Twitter:http://twitter.com/app_engine > > > > > > > > > > > > > > > > On Thu, Nov 11, 2010 at 8:38 AM, Mark <mar...@gmail.com> wrote: > > > Hi, > > > > > Is a Text property lazy loaded when I query for an instance of that > > > class? It seems to not be lazy loaded as of 2008, wondering if that's > > > still the case?: > > > > >http://groups.google.com/group/google-appengine/browse_thread/thread/. > .. > > > > > I ask because I'm wondering if a query for a class is spending time > > > deserializing my large Text properties, or waiting until I actually > > > access them (if ever) after the query is already performed, > > > > > Thanks > > > > > -- > > > You received this message because you are subscribed to the Google > Groups > > > "Google App Engine for Java" group. > > > To post to this group, send email to > > > google-appengine-j...@googlegroups.com. > > > To unsubscribe from this group, send email to > > > google-appengine-java+unsubscr...@googlegroups.com<google-appengine-java%2bunsubscr...@googlegroups.com><google-appengine-java%2B > unsubscr...@googlegroups.com> > > > . > > > For more options, visit this group at > > >http://groups.google.com/group/google-appengine-java?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine for Java" group. > To post to this group, send email to > google-appengine-j...@googlegroups.com. > To unsubscribe from this group, send email to > google-appengine-java+unsubscr...@googlegroups.com<google-appengine-java%2bunsubscr...@googlegroups.com> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine-java?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
