CSM - Courseware Student Module Touch Points

Part of PLAT-2436, this is an attempt to discover where the StudentModule model and table are read/written, for the purpose of crafting a solution to update its primary key from a signed int to an unsigned bigint.

Direct access to the StudentModule model:

Selects:

• The class dashboard aggregates or selects across many StudentModule rows in single queries in these places:
  • https://github.com/edx/edx-platform/blob/master/lms/djangoapps/class_dashboard/dashboard_data.py#L37
  • https://github.com/edx/edx-platform/blob/master/lms/djangoapps/class_dashboard/dashboard_data.py#L80
  • https://github.com/edx/edx-platform/blob/master/lms/djangoapps/class_dashboard/dashboard_data.py#L109
  • https://github.com/edx/edx-platform/blob/master/lms/djangoapps/class_dashboard/dashboard_data.py#L430
  • https://github.com/edx/edx-platform/blob/master/lms/djangoapps/class_dashboard/dashboard_data.py#L494
• Direct aggregate SELECT SQL executed here:
  • https://github.com/edx/edx-platform/blob/master/openedx/core/lib/xblock_utils/__init__.py#L271
  • Comment: "Print out a histogram of grades on a given problem in staff member debug info."
• CourseBlocks
  • Gets a single user/course/block row: https://github.com/edx/edx-platform/blob/master/lms/djangoapps/course_blocks/utils.py#L25
• ScoresClient
  • Gets multiple user/course/block rows: https://github.com/edx/edx-platform/blob/master/lms/djangoapps/courseware/model_data.py#L952
• Courseware
  • Get on a single row: https://github.com/edx/edx-platform/blob/master/lms/djangoapps/courseware/model_data.py#L1030
• The admin site

Writes:

• Instructor enrollment:
  • Resets the number of attempts on a problem via save(): https://github.com/edx/edx-platform/blob/master/lms/djangoapps/instructor/enrollment.py#L324
• CourseBlocks
  • Modifies learner state: https://github.com/edx/edx-platform/blob/master/lms/djangoapps/course_blocks/transformers/library_content.py#L101
• Courseware
  • get_or_create for an individual row, plus a get, plus an update: https://github.com/edx/edx-platform/blob/master/lms/djangoapps/courseware/model_data.py#L993
• The admin site

Deletes:

• The admin site

Caches:

• FieldDataCache: https://github.com/edx/edx-platform/blob/master/lms/djangoapps/courseware/model_data.py#L680

Indirect access to StudentModule:

• LTI forces a publish of a user's score on a problem in these two places, which claims to eventually write to StudentModule:
  • https://github.com/edx/edx-platform/blob/master/common/lib/xmodule/xmodule/lti_2_util.py#L225
  • https://github.com/edx/edx-platform/blob/master/common/lib/xmodule/xmodule/lti_2_util.py#L237

Special cases:

• Tests that rely on StudentModuleFactory (many)
• BokChoy tests use a cached schema that may need to be taken into consideration:
  • https://github.com/edx/edx-platform/blob/master/common/test/db_cache/bok_choy_schema_default.sql#L1681
• Tests that check query counts on these tables:
  • https://github.com/edx/edx-platform/blob/master/lms/djangoapps/courseware/tests/test_model_data.py