We've been working on a "billing optimization project" for our large app, steprep. Right now, we are tackling index optimizations - datastore writes form the largest part of our bill.
Zig zag merge has let us do some really crazy and unexpected things - in a good way. Thanks! However, we're somewhat concerned with the long term health of these queries. That is, today, they work and will offer us substantial savings over previous index approaches. But algorithm changes and data distribution changes may make our queries perform quite differently over time. (We have the additional difficulty of our test deployment having a different data distribution than our prod deployment, so we kind of have to cross our fingers and hope for the best when dropping indexes on prod...) It would be great to get some meta information back from a query to help track the efficiency of our zig zag merge queries over time (i.e., as data distributions change). E.g.: - which indexes were used to generate the results - how much zig-zag "thrashing" occurred (perhaps how many entries you needed to consider to find the results) - tell the query planner to _not_ use a particular index, so that we can simulate the drop of an optimal index to test if zig zag will be efficient I'm really excited about what we can do with zig zag, but we have concerns about how we will keep it healthy over time. I've opened http://code.google.com/p/googleappengine/issues/detail?id=5978 for this request; please star it if you feel it would be helpful. Thanks, j -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com. To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
