add index for query leaderboard ranking (#451)

add index for query leaderboard ranking

Author: yangw-dev

src/migrations/20260226_01_WgYAV-queryindex.py

@@ -0,0 +1,42 @@
+"""
+queryindex
+"""
+
+from yoyo import step
+
+__depends__ = {'20260225_01_aW5Bu-add-leaderboard-performance-indexes'}
+
+
+steps = [
+    # Most critical: partial composite index on runs
+    step(
+        """
+        CREATE INDEX IF NOT EXISTS idx_runs_valid_scores
+        ON leaderboard.runs (submission_id, runner, score)
+        WHERE NOT secret AND score IS NOT NULL AND passed;
+        """,
+        """
+        DROP INDEX IF EXISTS leaderboard.idx_runs_valid_scores;
+        """
+    ),
+    # Secondary: index on submission.leaderboard_id
+    step(
+        """
+        CREATE INDEX IF NOT EXISTS idx_submission_leaderboard_id
+        ON leaderboard.submission (leaderboard_id);
+        """,
+        """
+        DROP INDEX IF EXISTS leaderboard.idx_submission_leaderboard_id;
+        """
+    ),
+    # Secondary: index on submission.user_id
+    step(
+        """
+        CREATE INDEX IF NOT EXISTS idx_submission_user_id
+        ON leaderboard.submission (user_id);
+        """,
+        """
+        DROP INDEX IF EXISTS leaderboard.idx_submission_user_id;
+        """
+    ),
+]