Ah, thanks for the clarification! This is indeed very different from e.g. indexing in mysql. I'm used to build composite indexes, assuming that the first indexed column will be used in queries for that column only, too.
May I suggest that somewhere down the line, extending the documentation page for indexes would be really helpful. I believe a "beginner's guide to GAE indexes" would be a great thing to have: How are indexes used, defined, uploaded, deleted. The current document has this info, but some of it is difficult to understand as the BigTable datastore is so fundamentally different from classical databases. At least that's my feeling. Thanks again, Ben On Oct 19, 3:02 pm, "Nick Johnson (Google)" <[email protected]> wrote: > Hi Ben, > > On Sun, Oct 18, 2009 at 10:14 PM, bsb <[email protected]> wrote: > > > I'm struggling a bit with this. I'm trying to bulk dump an entity in > > my datastore. I get the following info: > > > [INFO ] Model_mobileapp: No descending index on __key__, performing > > serial download > > > Now, I added the following index: > > - kind: Model_mobileapp > > properties: > > - name: __key__ > > direction: desc > > - name: appId > > The problem here is the additional field. The index has to exactly match the > query; if the query doesn't have an 'appId' filter or sort, this index > cannot be used. > > -Nick Johnson > > > > > > > > > The index built fine and is serving. However, I still don't get > > parallel fetching. Why is that? Does that have to do with me using > > AppEnginePatch for Django, which makes a bit of a mess out of the > > datastore? The class to this entity is actually called MobileApp in > > module Model (ie. Model.MobileApp). However, doing a fetch on that > > entity name works fine: > > > q = db.GqlQuery("SELECT * FROM Model_mobileapp").fetch(10) > > > gives results. Any suggestions on how this can be fixed? GAE-style > > indexes are still a bit of a mystery to me, I must admit... > > > TIA, > > Ben > > -- > Nick Johnson, Developer Programs Engineer, App Engine > Google Ireland Ltd. :: Registered in Dublin, Ireland, Registration Number: > 368047 --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
