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"Geoboxing is a technique used to search for entities near a point on the earth in a database that can only perform equality queries (like App Engine)" So thei
by vosper 15y ago
"Geoboxing is a technique used to search for entities near a point on the earth in a database that can only perform equality queries (like App Engine)"
So their implementation is a compromise on account of GAE's limitations, and they have to pay through the nose to use it. This is when I'd be looking at hosting some features outside of GAE, which is what we do with Full-text Search.
- stickfigure 15y agoNo single platform or environment encompasses every use case. GAE doesn't offer R-trees or other spatial indexes; for that matter neither does MongoDB or MySQL. Geohashing is a reasonable solution for some spatial problem domains; it's one solution along the spectrum of "precalculate a lot up front and make queries cheap" vs "write in a cheap & easy format but make queries more expensive". Pre-calculation strategies are usually more scalable when you have large query loads, but they suck bigtime if you need to fully recalculate a large body of data (as the original blog author is doing). Maybe the blogger would be better off using PostGIS; but then, scaling and synchronizing a large cluster of PostGIS systems is nontrivial. The issues here are too application-specific to draw any positive or negative conclusions about appengine.
- jhaglund 15y agoFYI, MySQL supports R-trees on MyISAM tables: http://dev.mysql.com/doc/refman/5.0/en/creating-spatial-indexes.html http://dev.mysql.com/doc/refman/5.0/en/creating-spatial-inde...