On Dec 6, 1:47 am, lock <[EMAIL PROTECTED]> wrote: > Thanks guys, that's what I was hoping to hear, you saved me a couple > hours trying to prove it for myself (not to mention the frustration). > After I went away and thought about it some more I figured there must > be some 'smarts' in the database to prevent the query time from > increasing. Otherwise how could any database scale well... > > No merge joins or IN operators in my code, so nothing to worry about > there. > > After a _lot_ more testing I'm finding that query time does scale with > the number of fetched _results_, not the DB size. During early > testing I convinced myself that increasing the DB size was slowing my > query down, when really the number of results were increasing as I > added more data, doh (it was getting late ;-) ).
One thing to bear in mind is that the dev_appserver performance is _not_ representative of the production performance. The dev_appserver holds the entire dataset in memory and does linear scans over an entity type for queries, so performance there _will_ degrade with respect to the size of an entity type. > > The overall solution that seems to be working well for me at the > moment is to have different tables for different resolutions. As the > size of the geometric bounds increases I switch between a few tables, > each one with a lower fidelity therefore reducing the number of > results that can be returned. Visually it works similar to Level Of > Detail techniques you see in some 3D modeling packages. I'm curious how you're doing this with only a limited number of queries. Geohashing isn't ideally suited to satisfying bounding box queries (though it's certainly better than storing plain lat/longs). --~--~---------~--~----~------------~-------~--~----~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
