diff --git a/migrations/143_category.sql b/migrations/143_category.sql
index cedb3b8..4cf6a76 100644
--- a/migrations/143_category.sql
+++ b/migrations/143_category.sql
@@ -1,30 +1,18 @@
 -- 143_category.sql
--- Document Server 통합 플랫폼 Section 1: category enum + ai_suggestion
+-- Document Server 통합 플랫폼 Section 1: doc_category enum 정의 (1/4)
 -- plan: luminous-sprouting-hamster.md §1
 --
--- doc_category enum (6 활성 + 3 유보):
---   document / library / news / memo / audio / video
---   mail / calendar / plex (유보)
+-- asyncpg prepared statement 는 single-command 만 허용.
+-- 원래 한 파일이던 §1 스키마 변경을 4개로 분리:
+--   143: CREATE TYPE doc_category
+--   144: ALTER TABLE documents ADD category / ai_suggestion
+--   145: CREATE INDEX idx_documents_category
+--   146: CREATE INDEX idx_documents_has_suggestion
 --
--- ai_suggestion (JSONB): 승인 전 제안 payload
---   {
---     proposed_category, proposed_path, proposed_doctype,
---     confidence, source_updated_at, reason
---   }
--- 자동 전이 금지 — /accept-suggestion 승인 시에만 category / user_tags 변경
+-- 6 활성: document / library / news / memo / audio / video
+-- 3 유보: mail / calendar / plex
 
 CREATE TYPE doc_category AS ENUM (
   'document', 'library', 'news', 'memo', 'audio', 'video',
   'mail', 'calendar', 'plex'
 );
-
-ALTER TABLE documents
-  ADD COLUMN IF NOT EXISTS category       doc_category,
-  ADD COLUMN IF NOT EXISTS ai_suggestion  JSONB;
-
-CREATE INDEX IF NOT EXISTS idx_documents_category
-  ON documents(category);
-
-CREATE INDEX IF NOT EXISTS idx_documents_has_suggestion
-  ON documents(id)
-  WHERE ai_suggestion IS NOT NULL;
diff --git a/migrations/144_documents_category_columns.sql b/migrations/144_documents_category_columns.sql
new file mode 100644
index 0000000..476a902
--- /dev/null
+++ b/migrations/144_documents_category_columns.sql
@@ -0,0 +1,14 @@
+-- 144_documents_category_columns.sql
+-- Section 1: documents 에 category / ai_suggestion 컬럼 추가 (2/4)
+-- plan: luminous-sprouting-hamster.md §1
+--
+-- ai_suggestion 구조:
+--   {
+--     proposed_category, proposed_path, proposed_doctype,
+--     confidence, source_updated_at, reason
+--   }
+-- 자동 전이 금지 — /accept-suggestion 승인 시에만 category / user_tags 변경
+
+ALTER TABLE documents
+  ADD COLUMN IF NOT EXISTS category       doc_category,
+  ADD COLUMN IF NOT EXISTS ai_suggestion  JSONB;
diff --git a/migrations/145_documents_category_idx.sql b/migrations/145_documents_category_idx.sql
new file mode 100644
index 0000000..58c0ea7
--- /dev/null
+++ b/migrations/145_documents_category_idx.sql
@@ -0,0 +1,6 @@
+-- 145_documents_category_idx.sql
+-- Section 1: category 필터 인덱스 (3/4)
+-- plan: luminous-sprouting-hamster.md §1
+
+CREATE INDEX IF NOT EXISTS idx_documents_category
+  ON documents(category);
diff --git a/migrations/146_documents_has_suggestion_idx.sql b/migrations/146_documents_has_suggestion_idx.sql
new file mode 100644
index 0000000..82d1a3f
--- /dev/null
+++ b/migrations/146_documents_has_suggestion_idx.sql
@@ -0,0 +1,9 @@
+-- 146_documents_has_suggestion_idx.sql
+-- Section 1: 승인 대기 제안 partial index (4/4)
+-- plan: luminous-sprouting-hamster.md §1
+--
+-- 승인 UI 가 hit 하는 SELECT ... WHERE ai_suggestion IS NOT NULL 용 partial idx.
+
+CREATE INDEX IF NOT EXISTS idx_documents_has_suggestion
+  ON documents(id)
+  WHERE ai_suggestion IS NOT NULL;