[PERFORMANCE] [MER-5838] Scope Insights page attempts to delivery

[nicocirio]

Jira

• Ticket: https://eliterate.atlassian.net/browse/MER-5838

Summary

Scopes Oli.Publishing.DeliveryResolver.students_with_attempts_for_page/3 to the
delivery project (project_id = -1).

Previously, the query included resource_summary rows from unrelated authoring
projects that happened to reference the same resource. That could include students
without delivery attempts for the selected page and caused the page-detail query to
scan a large portion of resource_summary.

The new scope returns only delivery analytics data and lets PostgreSQL use the
existing resource_summary_scopes index.

Performance Impact

Validation used a dedicated local database with 10,000,351 resource_summary
rows: 500 enrolled students, 350 delivery attempts on the selected scored page,
and 10,000 unrelated project scopes per student across scored and practice pages.
Both query versions ran against this exact same dataset.

Each query was measured five times with EXPLAIN ANALYZE; the values below are
median execution times.

Query	Original	With this change	Improvement
Oli.Publishing.DeliveryResolver.students_with_attempts_for_page/3	3,797.59 ms	1.04 ms	3,796.55 ms (99.97%, ~3,651x)

The original plan used a parallel sequential scan over approximately 5 million
page-related resource_summary rows, including unrelated project scopes. The
updated plan uses an index-only scan through resource_summary_scopes and reads
only the relevant delivery scope.

The temporary seed and benchmark harness is preserved for reference in
benchmark v1.

Validation

• Added a regression test proving that only delivery-scope attempt summaries are
  considered.
• Ran mix test test/oli/publishing/delivery_resolver_students_with_attempts_test.exs.
• Manually navigated to the selected scored-page detail view and applied its
  filters with the same seeded database: approximately five seconds on master,
  effectively instantaneous on this branch.

Video Evidence

Before (master)

before.mov

After (this branch)

after.mov

[gitguardian]

⚠️ GitGuardian has uncovered 1 secret following the scan of your pull request.

Please consider investigating the findings and remediating the incidents. Failure to do so may lead to compromising the associated services or software components.

🔎 Detected hardcoded secret in your pull request

GitGuardian id	GitGuardian status	Secret	Commit	Filename
36041959	Triggered	Company Email Password	950700a	priv/scenarios/insights_page_detail_perf.scenario.yaml	View secret

🛠 Guidelines to remediate hardcoded secrets

1. Understand the implications of revoking this secret by investigating where it is used in your code.
2. Replace and store your secret safely. Learn here the best practices.
3. Revoke and rotate this secret.
4. If possible, rewrite git history. Rewriting git history is not a trivial act. You might completely break other contributing developers' workflow and you risk accidentally deleting legitimate data.

To avoid such incidents in the future consider

• following these best practices for managing and storing secrets including API keys and other credentials
• install secret detection on pre-commit to catch secret before it leaves your machine and ease remediation.

---

^{🦉 GitGuardian detects secrets in your source code to help developers and security teams secure the modern development process. You are seeing this because you or someone else with access to this repository has authorized GitGuardian to scan your pull request.}

[github-actions]

Risk score: 4 → risk/medium

Generated by 🚫 dangerJS against 9d428ba

[github-actions]

AI Review — performance

No issues found

[github-actions]

AI Review — security

No issues found

[github-actions]

AI Review — elixir

No issues found