[Spatialindex] BulkLoader sorting dimension

[Marios Hadjieleftheriou]

No, STR will sort on all dimensions recursively starting from 0. Of 
course one could sort using a random permutation of dimensions and a get 
a different tree, but it shouldn't make much difference in the average case.

m_s should be incrementally incremented somewhere within bulk load, 
otherwise there is a bug.

Howard Butler wrote:
> Marios,
> 
> Does th bulk loader currently assumes it is going to sort on the 0'th 
> dimension first by default? It appears ExternalSorter::Record does have 
> a parameter that appears to take in the first sorting dimension 
> (ExternalSorter::Record::m_s), but it's not being used.  I propose to 
> implement the following (please let me know if I'm misunderstanding 
> what's going on or my proposal does not make sense):
> 
> - Add a void BulkLoader::bulkLoadUsingSTR overload that takes in the 
> sorting dimension
> - Add a "ExternalSortDimension" property to the Tools::PropertySet
> - Modify the createAndBulkLoadNewRTree method that takes in the 
> PropertySet to pass the sorting dimension
> - Optionally add an overload of the convenience 
> createAndBulkLoadNewRTree method that takes in explicit parameters to 
> include the sorting dimension
> - update BulkLoader::createLevel to take in the sorting dimension
> 
> Howard
>