One big advantage of polymodels is queries against the base class can/ will return all subclasses meeting the criteria.
You can't do that with normal python inheritance. You query is always bound to a particular model. That would be in my mind the single biggest reason to chose PolyModel vs inheritance. If you don't need that capability then it is probably not worth the overhead. T On Mar 5, 3:32 am, Jairo Vasquez <[email protected]> wrote: > My question was more about if it's better to use Polymodel or just use > python inheritance for this kind of Big entities with big wrote rate. > > On Mar 1, 7:16 pm, "Ikai L (Google)" <[email protected]> wrote: > > > What's the current write rate? > > > In general, you want to minimize the number of writes. Are you doing > > transactional writes? Four entities will result in a minimum of four > > entities saved, however, it seems to me as if the number of indexes that > > need to be updated will be more of a factor in reducing overall resource > > consumption. Do you have any exploding > > indexes?http://code.google.com/appengine/docs/python/datastore/queriesandinde... > > > On Thu, Feb 25, 2010 at 1:43 PM, Jairo Vasquez Moreno < > > > [email protected]> wrote: > > > Hi all, > > > > I would like to refactor all my models but I need some assistance. Now I > > > have 4 separated models, each of them has a rate of 2 per second creation > > > of > > > the entity. From how I'm modeling the new scheme of models there is a new > > > parent model that have 4 childs. The problem is that with the current > > > write > > > rate of those models I started to see "too much contention error", I think > > > that is caused because for each write GAE create index entries. > > > > I know that if I create a polymodel all four kind of entities will be > > > stored in GAE as one model kind (parent) so I think for each child index > > > everything will go now to the same entity so everything will go worst. > > > > Is it better if I just use db.Model for the parent model and use python > > > inheritance for childs? What do I lost from GAE functions or something if > > > I > > > don't user polymodel? Am I wrong about indexes and contention for > > > polymodel-child entities? > > > > Thanks in advance > > > > -- > > > Jairo Vasquez Moreno > > > Mentez Developer > > >www.mentez.com > > > Medellin - Colombia > > > > -- > > > 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%2Bunsubscrib > > > [email protected]> > > > . > > > For more options, visit this group at > > >http://groups.google.com/group/google-appengine?hl=en. > > > -- > > Ikai Lan > > Developer Programs Engineer, Google App > > Enginehttp://googleappengine.blogspot.com|http://twitter.com/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.
