diff --git a/migrations/153_analyze_events_shadow.sql b/migrations/153_analyze_events_shadow.sql
index 4dd9f35..3a36c81 100644
--- a/migrations/153_analyze_events_shadow.sql
+++ b/migrations/153_analyze_events_shadow.sql
@@ -1,12 +1,14 @@
 -- 153_analyze_events_shadow.sql
--- AI Policy Layer (PR-A) — shadow 관측용 컬럼만 추가. 아무도 쓰지 않음.
+-- AI Policy Layer (PR-A) — shadow 관측용 컬럼 추가. 아무도 쓰지 않음.
 -- PR-B 가 DBShadowLogger 구현 후 writer 추가 예정.
 --
 -- plan: ~/.claude/plans/wise-gliding-hippo.md
 -- axis 원칙: feedback_category_vs_ai_domain_axis.md (subject_domain 은 정책 축,
 --            documents.category 매칭 키로 쓰지 않음)
 --
--- 주의: _run_migrations 는 단일 outer 트랜잭션으로 실행됨 — BEGIN/COMMIT 금지.
+-- 주의: _run_migrations 는 asyncpg exec_driver_sql 로 단일 prepared statement 실행 —
+--       한 파일에 단일 SQL statement 만 허용 (multi-statement 시 PostgresSyntaxError).
+--       index 는 migrations 154/155 로 분리.
 
 ALTER TABLE analyze_events
     ADD COLUMN IF NOT EXISTS subject_domain        TEXT,
@@ -19,11 +21,3 @@ ALTER TABLE analyze_events
     ADD COLUMN IF NOT EXISTS policy_violation_ids  TEXT[],
     ADD COLUMN IF NOT EXISTS shadow_would_route_to TEXT,
     ADD COLUMN IF NOT EXISTS policy_version        TEXT;
-
-CREATE INDEX IF NOT EXISTS idx_analyze_events_shadow_ts
-    ON analyze_events (created_at)
-    WHERE shadow_would_route_to IS NOT NULL;
-
-CREATE INDEX IF NOT EXISTS idx_analyze_events_policy_violation
-    ON analyze_events (created_at)
-    WHERE policy_violation = true;
diff --git a/migrations/154_analyze_events_shadow_idx_ts.sql b/migrations/154_analyze_events_shadow_idx_ts.sql
new file mode 100644
index 0000000..8119225
--- /dev/null
+++ b/migrations/154_analyze_events_shadow_idx_ts.sql
@@ -0,0 +1,7 @@
+-- 154_analyze_events_shadow_idx_ts.sql
+-- PR-A: shadow_would_route_to 기반 조회 인덱스 (migration 153 분할).
+-- shadow 기간 대시보드/분석 쿼리용 partial index.
+
+CREATE INDEX IF NOT EXISTS idx_analyze_events_shadow_ts
+    ON analyze_events (created_at)
+    WHERE shadow_would_route_to IS NOT NULL;
diff --git a/migrations/155_analyze_events_policy_violation_idx.sql b/migrations/155_analyze_events_policy_violation_idx.sql
new file mode 100644
index 0000000..51d05f9
--- /dev/null
+++ b/migrations/155_analyze_events_policy_violation_idx.sql
@@ -0,0 +1,7 @@
+-- 155_analyze_events_policy_violation_idx.sql
+-- PR-A: policy_violation=true 행 추출 인덱스 (migration 153 분할).
+-- under_escalation 재처리 큐 + 야간 sweep 감사용 partial index.
+
+CREATE INDEX IF NOT EXISTS idx_analyze_events_policy_violation
+    ON analyze_events (created_at)
+    WHERE policy_violation = true;