Potential performance issues with requests to DB

[volodymyrdovhan]

Hello,
Plugin contains nested database queries within loops, causing N+1 query problems that can severely impact performance on production sites with large datasets.

• How to fix:
  • Move DB calls outside loops by preloading required records in bulk.
  • Use get_records_sql() with grouped queries and get_in_or_equal() where applicable.
  • Iterate over in-memory results instead of querying $DB per loop iteration.

Documentation:

• https://moodledev.io/docs/4.5/apis/core/dml#performance

Code excerpts:

• File: coursereport.php

239:     // Verdict severity ordering for roll-up "worst" verdict.
240:     $verdictseverity = [
241:         'LIKELY_HUMAN' => 0,
242:         'LOW_SUSPICION' => 1,
243:         'SUSPICIOUS' => 2,
244:         'PROBABLE_AGENT' => 3,
245:         'HIGH_CONFIDENCE_AGENT' => 4,
246:     ];
248:     foreach ($sessions as $session) {
249:         $totalsessions++;
251:         // Load the highest-scoring combined signal record for this session.
252:         $signalrecord = $DB->get_record_sql(