Add indexes to 'grade' and 'modified' on StudentGradebook

lms/djangoapps/gradebook/migrations/0004_auto__add_index_studentgradebook_created__add_index_studentgradebook_g.py

+# -*- coding: utf-8 -*-
+# pylint: disable=unused-argument, line-too-long, missing-docstring, invalid-name
+from south.db import db
+from south.v2 import SchemaMigration
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Adding index on 'StudentGradebook', fields ['created']
+        db.create_index('gradebook_studentgradebook', ['created'])
+
+        # Adding index on 'StudentGradebook', fields ['grade']
+        db.create_index('gradebook_studentgradebook', ['grade'])
+
+        # Adding index on 'StudentGradebook', fields ['modified']
+        db.create_index('gradebook_studentgradebook', ['modified'])
+
+    def backwards(self, orm):
+        # Removing index on 'StudentGradebook', fields ['modified']
+        db.delete_index('gradebook_studentgradebook', ['modified'])
+
+        # Removing index on 'StudentGradebook', fields ['grade']
+        db.delete_index('gradebook_studentgradebook', ['grade'])
+
+        # Removing index on 'StudentGradebook', fields ['created']
+        db.delete_index('gradebook_studentgradebook', ['created'])
+
+    models = {
+        'auth.group': {
+            'Meta': {'object_name': 'Group'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'})
+        },
+        'auth.permission': {
+            'Meta': {'ordering': "('content_type__app_label', 'content_type__model', 'codename')", 'unique_together': "(('content_type', 'codename'),)", 'object_name': 'Permission'},
+            'codename': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'auth.user': {
+            'Meta': {'object_name': 'User'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
+            'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
+        },
+        'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        'gradebook.studentgradebook': {
+            'Meta': {'unique_together': "(('user', 'course_id'),)", 'object_name': 'StudentGradebook'},
+            'course_id': ('xmodule_django.models.CourseKeyField', [], {'db_index': 'True', 'max_length': '255', 'blank': 'True'}),
+            'created': ('model_utils.fields.AutoCreatedField', [], {'default': 'datetime.datetime.now', 'db_index': 'True'}),
+            'grade': ('django.db.models.fields.FloatField', [], {'db_index': 'True'}),
+            'grade_summary': ('django.db.models.fields.TextField', [], {'blank': 'True'}),
+            'grading_policy': ('django.db.models.fields.TextField', [], {'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'modified': ('model_utils.fields.AutoLastModifiedField', [], {'default': 'datetime.datetime.now', 'db_index': 'True'}),
+            'proforma_grade': ('django.db.models.fields.FloatField', [], {}),
+            'progress_summary': ('django.db.models.fields.TextField', [], {'blank': 'True'}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']"})
+        },
+        'gradebook.studentgradebookhistory': {
+            'Meta': {'object_name': 'StudentGradebookHistory'},
+            'course_id': ('xmodule_django.models.CourseKeyField', [], {'db_index': 'True', 'max_length': '255', 'blank': 'True'}),
+            'created': ('model_utils.fields.AutoCreatedField', [], {'default': 'datetime.datetime.now'}),
+            'grade': ('django.db.models.fields.FloatField', [], {}),
+            'grade_summary': ('django.db.models.fields.TextField', [], {'blank': 'True'}),
+            'grading_policy': ('django.db.models.fields.TextField', [], {'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'modified': ('model_utils.fields.AutoLastModifiedField', [], {'default': 'datetime.datetime.now'}),
+            'proforma_grade': ('django.db.models.fields.FloatField', [], {}),
+            'progress_summary': ('django.db.models.fields.TextField', [], {'blank': 'True'}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']"})
+        }
+    }
+
+    complete_apps = ['gradebook']

lms/djangoapps/gradebook/models.py

@@ -8,24 +8,29 @@ from django.db import models
 from django.db.models import Avg, Max, Min, Count
 from django.db.models.signals import post_save
 from django.dispatch import receiver
+from django.utils.translation import ugettext_lazy as _
+from model_utils.fields import AutoCreatedField, AutoLastModifiedField
 
 from model_utils.models import TimeStampedModel
 from student.models import CourseEnrollment
 from xmodule_django.models import CourseKeyField
 
 
-class StudentGradebook(TimeStampedModel):
+class StudentGradebook(models.Model):
     """
     StudentGradebook is essentially a container used to cache calculated
     grades (see courseware.grades.grade), which can be an expensive operation.
     """
     user = models.ForeignKey(User, db_index=True)
     course_id = CourseKeyField(db_index=True, max_length=255, blank=True)
-    grade = models.FloatField()
+    grade = models.FloatField(db_index=True)
     proforma_grade = models.FloatField()
     progress_summary = models.TextField(blank=True)
     grade_summary = models.TextField(blank=True)
     grading_policy = models.TextField(blank=True)
+    # We can't use TimeStampedModel here because those fields are not indexed.
+    created = AutoCreatedField(_('created'), db_index=True)
+    modified = AutoLastModifiedField(_('modified'), db_index=True)
 
     class Meta:
         """