I've watched this video, so I watched again. At first he says he thinks filter order might matter, but then corrects himself based on input from the author of the code to say that filter order has a very small effect.
On Sep 2, 5:52 am, Paul Kinlan <[email protected]> wrote: > There is a video about building scalable apps by Brett Slatkin > onhttp://code.google.com/io > At the end of the video it is hinted (I believe - I could be wrong) that the > order of your filters matters, so that means that you should choose key with > the highest entropy first (my terminology might be incorrect) but if your > data is not very unique it should be used later in the merge join query. > > Paul > > 2009/9/2 Jai <[email protected]> > > > > > Also does it use the keyword histogram to optimize the set- > > intersection performance(AND queries) in merge-join? > > > Regards, > > Jai > > > On Sep 1, 12:07 pm, Devel63 <[email protected]> wrote: > > > I'm seeing very slow times on some merge-join (zig zag) queries, and > > > just want to confirm that App Engine is smart about these things. > > > > In particular, if I have a poperty for which most records have an > > > identical value, does GAE does have to scan the related entire index > > > linearly, or, if I'm in the middle of a merge join, does it > > > intelligently find a good starting point based on the desired __key__ > > > value? > > > > Imagine 1M records with a db.BooleanProperty set to False... --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
