[gdal-dev] Spatialite 4 and InitSpatialMetaData

[Jukka Rahkonen]

Hi,

I noticed a huge difference in running either InitSpatialMetaData() or
InitSpatialMetaData(1) on a rather weak Windows 32-bit computer with
Spatialite version 4.1.1. The first variant took 18 minutes vs. 3 seconds
for the latter.

This must have to do with making either one big or thousands of small
transactions when populating the spatial_ref_sys table.
https://www.gaia-gis.it/gaia-sins/xmlBlob/spatialite-sql-latest.html.

I am not sure from which Spatialite version this setting is supported but it
might be worth checking how GDAL behaves. I think it should use
"InitSpatialMetaData(1)" if it is supported. Option is said to be less safe
than the default setting "transaction=false" but function is used when an
new database is created so there is no risk for corrupting data.

The speed of the function with default value is so awfully slow that it
feels like a bug in Spatialite.

-Jukka Rahkonen-