update shard module to use ST_Subdivide #19
Merged
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This is a big refactor of the
shard
module to use the new ST_Subdivide() functionality only available in [email protected]This is a cutting-edge feature which requires building from source in order to get all the latest features in
[email protected]
The major advantages are a 4x speed improvement on build times and increased stability when generating shards for PIP.
More information is available in the documentation:
https://www.gaia-gis.it/fossil/libspatialite/wiki?name=About+ST_Subdivide%28%29
I've removed my home-grown splitting code which splits polygons alternately horizontally/vertically, I don't foresee any reason we would need to bring that code back but it's in the history if we ever need to support older versions of spatialite.
related: #7 #6