Thanks Ikai for 1. Will definitely refer to the link in 2. and get back if I have more questions.
Thanks for the quick help. On Mon, Dec 21, 2009 at 9:38 AM, Ikai L (Google) <ika...@google.com> wrote: > 1. If you just delete all the entities of a single Kind, it is the same > effect as deleting a "table". You have to remember that the datastore is not > SQL. Underneath the hood, it is a schemaless key-value store. Type > information is defined within each entity itself and in the corresponding > indexes. > > 2. The solution that seems to fit for the most developers is to do multiple > queries and join in memory. Another solution can be to precompute the result > at write time and denormalize your schema so that you query on the > denormalized field. Without knowing what you are doing, it can be difficult > to recommend any particular workaround. I highly recommend watching the > videos from Google I/O and reading the articles to understand how filtering > and indexing works. This is a pretty good place to start: > http://code.google.com/appengine/articles/datastore/overview.html > > > On Fri, Dec 18, 2009 at 10:12 PM, Bombay Goose <bombaygo...@gmail.com>wrote: > >> Thanks DataNucleus team and Toby. >> >> Sorry, but I have some more questions >> >> 1. How do I delete a particular table dynamically? would just unloading >> the class do it? Iin that case, what if there are changes to the dynamic >> table, i.e. column addition/dropping, wouldnt that require unloading the >> class and hence deletion of table? >> 2. I am going through the Queries and Indexes section in the documentation >> at >> http://code.google.com/appengine/docs/java/datastore/queriesandindexes.html >> This section says that inequality operators are allowed only one >> property. Is anybody handling a situation where there are multiple >> properties with inequality operators? If yes, how have you done it? >> Thanks >> On Wed, Dec 16, 2009 at 12:18 PM, Toby Reyelts <to...@google.com>wrote: >> >>> One other thing you might consider is using the native App Engine >>> datastore, since it's already schemaless. You can even mix and match using >>> the native API and JDO/JPA. >>> >>> On Wed, Dec 16, 2009 at 1:30 AM, Bombay Goose >>> <bombaygo...@gmail.com>wrote: >>> >>>> Hello All, >>>> >>>> I am doing a feasibility study of whether we can develop our application >>>> on appengine or not. >>>> >>>> Our application has a requirement where we have to create tables >>>> dynamically, without restarting the application. >>>> >>>> Is that possible in Appengine? >>>> >>>> Datanucleus supports this through JDO, with some byte code >>>> instrumentation. More info - >>>> http://www.jpox.org/servlet/wiki/pages/viewpage.action?pageId=6619188 >>>> >>>> Is it possible through JPA? if yes, does appengine allow it? >>>> if not, does Appengine allow Bytecode instrumentation so that we >>>> can create classes dynamically according to the link above using JDO. >>>> >>>> Any help is greatly appreciated. >>>> >>>> Thanks, >>>> >>>> G >>>> >>>> -- >>>> 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<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<google-appengine-java%2bunsubscr...@googlegroups.com> >> . >> For more options, visit this group at >> http://groups.google.com/group/google-appengine-java?hl=en. >> > > > > -- > Ikai Lan > Developer Programs Engineer, Google App Engine > > -- > 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.
