Diskussion:HSR Texas Geo Database Benchmark

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Feel free to discusss 'HSR Texas Spatial Database Benchmark' issues here! Stefan 18:39, 22. Dez. 2009 (CET)

To do

  • Standardise data and input process (circumvent or minimize floating point problem)
  • Define the variables (@bbox and @point)



  • MS SQL Server representatives report that geography types are 20-30% slower than geometry types.
  • About PostGIS 1.5 there was said, that geography types are somewhat faster (see http://blog.cleverelephant.ca/)
  • Secondary index optimization makes performance about 50% faster (from: MS SQL Server discussion)
  • The number of points of a query window is important for a secondary filter overhead.

Data and queries per se:

  • These queries return quite large percent of the data overall (50%-100% for points and polygons)
  • The Number of points for a query windows is very small.
  • The query windows are "aligned bounding boxes" which may put in favor RTree (e.g. Postgres) or spatial grid (SQL Server) index, depending on a position of the window. If the window is aligned with the grid, performance can be much faster than when it's slightly off.
  • Volker Mische reported that boundingbox queries with different boundingboxes (selecting 5%, 10%, 15%, 20%, 25% of all features) show the same performance in spatialite.

Discussion Points

  • Should we take an average of multiple runs with different values (@point, @bbox)?
  • Should we vary the queries' result sizes? (see observations)
  • Should we vary the shape and alignment of the query window? (see observations)
  • Should we run the benchmark with parallelized queries?


  • Query 1 actually shouldn't be included in the benchmark, data copying and preparation isn't really done often in a spatial database.