[processing] Warn when we know for certain that no spatial index

exists on a source used for the Join by Location algorithm Advise users that performance will be severely degraded as a result.
qgis · Nov 17, 2019 · 8096b0b · 8096b0b
1 parent 8ced952
commit 8096b0b
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/python/plugins/processing/algs/qgis/SpatialJoin.py b/python/plugins/processing/algs/qgis/SpatialJoin.py
@@ -38,7 +38,8 @@
                        QgsProcessingParameterField,
                        QgsProcessingParameterFeatureSink,
                        QgsProcessingParameterString,
-                       QgsProcessingOutputNumber)
+                       QgsProcessingOutputNumber,
+                       QgsFeatureSource)
 
 from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
 from processing.tools import vector
@@ -206,6 +207,9 @@ def processAlgorithm(self, parameters, context, feedback):
         features = join_source.getFeatures(request)
         total = 100.0 / join_source.featureCount() if join_source.featureCount() else 0
 
+        if source.hasSpatialIndex() == QgsFeatureSource.SpatialIndexNotPresent:
+            feedback.reportError(self.tr('No spatial index exists for input layer, performance will be severely degraded'))
+
         joined_count = 0
         unjoined_count = 0