Merge pull request #1520 from laws-africa/speed-rels

smarter relationship loading to avoid N+1

peachjam/models/core_document_model.py

@@ -14,7 +14,6 @@
 from django.core.exceptions import ValidationError
 from django.core.files import File
 from django.db import models
-from django.utils.functional import cached_property
 from django.utils.text import slugify
 from django.utils.translation import gettext_lazy as _
 from docpipe.pipeline import PipelineContext
@@ -551,24 +550,6 @@ def save(self, *args, **kwargs):
         # apply labels
         self.apply_labels()
 
-    @cached_property
-    def relationships_as_subject(self):
-        """Returns a list of relationships where this work is the subject."""
-        from peachjam.models import Relationship
-
-        return Relationship.for_subject_document(self).prefetch_related(
-            "subject_work", "subject_work__documents"
-        )
-
-    @cached_property
-    def relationships_as_object(self):
-        """Returns a list of relationships where this work is the subject."""
-        from peachjam.models import Relationship
-
-        return Relationship.for_object_document(self).prefetch_related(
-            "object_work", "object_work__documents"
-        )
-
     def extract_citations(self):
         """Run citation extraction on this document. If the document has content_html,
         extraction will be run on that. Otherwise, if the document as a PDF source file,

peachjam/views/generic_views.py

@@ -196,13 +196,17 @@ def fetch_docs(self, works):
 
     def add_relationships(self, context):
         context["relationships_as_subject"] = rels_as_subject = list(
-            context["document"].relationships_as_subject.all()
+            Relationship.for_subject_document(context["document"])
+            .prefetch_related("subject_work")
+            .select_related("predicate")
         )
         context["relationships_as_object"] = rels_as_object = list(
-            context["document"].relationships_as_object.all()
+            Relationship.for_object_document(context["document"])
+            .prefetch_related("object_work")
+            .select_related("predicate")
         )
-        context["relationship_limit"] = 4
         context["n_relationships"] = len(rels_as_subject) + len(rels_as_object)
+        context["relationship_limit"] = 4
 
     def add_provision_relationships(self, context):
         rels = [