Name
DB.DBA.RDF_GEO_FILL — Converts geo:lat and geo:long properties properties into geometries.
Synopsis
DB.DBA.RDF_GEO_FILL ( |
n_threads integer (optional, default
4) ); |
Description
Converts geo:lat and geo:long properties into geometries. This operation reads through all graphs and for each subject with at least one geo:lat and geo:long, a point geometry is made for each distinct lat/long pair where lat and long are in the same graph.
It should not happen in practice that a single subject has multiple lats or long within one graph. If this still happens, a geometry is made for each combination. The geometry is added to the subject with the lat and long as the value of the geo:geometry property.
This is performed in parallel on multiple threads and is optimized for cluster execution and done without transaction logging and is not transactional. To make the result persistent, the operator should do an explicit checkpoint by executing:
SQL>cl_exec ('checkpoint');
on any process of a cluster or single server. Otherwise the result may be lost if the server terminates abnormally before an automatic checkpoint is made.
Parameters
n_threads
Number of threads to run. Default is to run 4 threads that will make geomerty objects (not counting the thread that searches for separate geo:lat and geo:long properties).
Examples
Example24.282.Simple example
SQL> rdf_geo_fill (); Done. -- 282 msec.