Merge pull request #36823 from openedx/iamsobanjaved/fix-csmh-index-migration

[DO NOT MERGE – Needs Staging Verification] fix!: Update the migration to have one Index on student_module_id

lms/djangoapps/coursewarehistoryextended/migrations/0003_rename_studentmodulehistoryextended_student_module_student_module_idx.py

@@ -1,6 +1,7 @@
 # Generated by Django 4.2.20 on 2025-05-15 03:30
 
-from django.db import migrations
+from django.db import migrations, models
+import django.db.models.deletion
 
 
 class Migration(migrations.Migration):
@@ -10,9 +11,26 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
-        migrations.RenameIndex(
+        migrations.AlterField(
             model_name='studentmodulehistoryextended',
-            new_name='student_module_idx',
-            old_fields=('student_module',),
+            name='student_module',
+            field=models.ForeignKey(db_constraint=False, db_index=False, on_delete=django.db.models.deletion.DO_NOTHING, to='courseware.studentmodule'),
+        ),
+        # This SeparateDatabaseAndState operation updates the state to match the model.
+        # database_operations is left empty because the indexes were already dropped
+        # by the previous operation in the database.
+        migrations.SeparateDatabaseAndState(
+            database_operations=[],
+            state_operations=[
+                migrations.AlterIndexTogether(
+                    name='studentmodulehistoryextended',
+                    index_together=set(),
+                ),
+            ],
+        ),
+        # Adds back the index on 'student_module' to ensure there is a single index on this field.
+        migrations.AddIndex(
+            model_name='studentmodulehistoryextended',
+            index=models.Index(fields=['student_module'], name='student_module_idx'),
         ),
     ]

lms/djangoapps/coursewarehistoryextended/models.py

@@ -42,7 +42,7 @@ class StudentModuleHistoryExtended(BaseStudentModuleHistory):
 
     id = UnsignedBigIntAutoField(primary_key=True)  # pylint: disable=invalid-name
 
-    student_module = models.ForeignKey(StudentModule, db_index=True, db_constraint=False, on_delete=models.DO_NOTHING)
+    student_module = models.ForeignKey(StudentModule, db_index=False, db_constraint=False, on_delete=models.DO_NOTHING)
 
     @receiver(post_save, sender=StudentModule)
     def save_history(sender, instance, **kwargs):  # pylint: disable=no-self-argument, unused-argument