Split meta document attributes into a document_meta table

CHANGELOG.md

@@ -1,6 +1,10 @@
 # Changelog
 ## [Unreleased]
 
+### Changed
+
+- Mutable document attributes (`uri`, `title`, `metadata`, `created_at`, `updated_at`) moved from the `documents` table into a new `document_meta` table (1:1 on `document_id`); metadata/title/`source_revision` updates no longer rewrite the docling blobs. Migration `v0_58_0` relocates existing data and runs a one-time `vacuum` to reclaim prior bloat.
+
 ### Fixed
 
 - Embedded PDF attachment extension is derived from the attachment filename, not the parent's synthetic `...#attachment=<name>` URI; non-PDF attachments (e.g. `.joboptions`) are no longer misrouted to docling's PDF backend, and unsupported extensions are skipped.

haiku_rag_slim/haiku/rag/client/documents.py

@@ -323,7 +323,7 @@ async def _refresh_doc_metadata(
         updated = True
 
     if updated:
-        return await client.document_repository.update(doc)
+        return await client.document_repository.update_meta(doc)
     return doc
 
 
@@ -730,7 +730,7 @@ async def update_document(
         existing_doc.metadata = metadata
 
     if content is None and chunks is None and docling_document is None:
-        return await client.document_repository.update(existing_doc)
+        return await client.document_repository.update_meta(existing_doc)
 
     if chunks is not None:
         if docling_document is not None:

haiku_rag_slim/haiku/rag/client/rebuild.py

@@ -192,7 +192,7 @@ async def _rebuild_title_only(
             continue
         if title is not None:
             doc.title = title
-            await client.document_repository.update(doc)
+            await client.document_repository.update_meta(doc)
             assert doc.id is not None
             yield doc.id
 
@@ -490,27 +490,35 @@ async def _flush_rebuild_batch(
     document. Used by RECHUNK and FULL modes after the chunks table has been
     cleared.
     """
-    from haiku.rag.store.engine import DocumentRecord
+    from haiku.rag.store.engine import DocumentMetaRecord, DocumentRecord
 
     if not documents:
         return
 
     now = datetime.now().isoformat()
 
-    # Batch update documents using merge_insert (single LanceDB version)
+    # Batch update documents and document_meta using merge_insert (one LanceDB
+    # version per table). Content+blobs go to documents; mutable attributes go
+    # to document_meta.
     doc_records = []
+    meta_records = []
     for doc in documents:
         assert doc.id is not None
         doc_records.append(
             DocumentRecord(
                 id=doc.id,
                 content=doc.content,
-                uri=doc.uri,
-                title=doc.title,
-                metadata=json.dumps(doc.metadata),
                 docling_document=doc.docling_document,
                 docling_pages=doc.docling_pages,
                 docling_version=doc.docling_version,
+            )
+        )
+        meta_records.append(
+            DocumentMetaRecord(
+                document_id=doc.id,
+                uri=doc.uri,
+                title=doc.title,
+                metadata=json.dumps(doc.metadata),
                 created_at=doc.created_at.isoformat() if doc.created_at else now,
                 updated_at=now,
             )
@@ -521,6 +529,12 @@ async def _flush_rebuild_batch(
         .when_matched_update_all()
         .execute(doc_records)
     )
+    await (
+        client.store.document_meta_table.merge_insert("document_id")
+        .when_matched_update_all()
+        .when_not_matched_insert_all()
+        .execute(meta_records)
+    )
 
     # Batch create all chunks (single LanceDB version)
     if chunks:

haiku_rag_slim/haiku/rag/store/engine.py

@@ -77,12 +77,20 @@ async def connect_lancedb(
 class DocumentRecord(LanceModel):
     id: str = Field(default_factory=lambda: str(uuid4()))
     content: str
-    uri: str | None = None
-    title: str | None = None
-    metadata: str = Field(default="{}")
     docling_document: bytes | None = None
     docling_pages: bytes | None = None
     docling_version: str | None = None
+
+
+class DocumentMetaRecord(LanceModel):
+    """Mutable, lightweight document attributes, kept separate from the
+    write-once content/blobs in `documents`. Updating these (metadata, title,
+    source_revision) must not rewrite the multi-MB docling row."""
+
+    document_id: str
+    uri: str | None = None
+    title: str | None = None
+    metadata: str = Field(default="{}")
     created_at: str = Field(default_factory=lambda: "")
     updated_at: str = Field(default_factory=lambda: "")
 
@@ -171,7 +179,13 @@ class SettingsRecord(LanceModel):
     settings: str = Field(default="{}")
 
 
-REQUIRED_TABLES: tuple[str, ...] = ("documents", "chunks", "document_items", "settings")
+REQUIRED_TABLES: tuple[str, ...] = (
+    "documents",
+    "document_meta",
+    "chunks",
+    "document_items",
+    "settings",
+)
 
 
 async def get_database_stats(db: lancedb.AsyncConnection) -> dict:
@@ -390,19 +404,18 @@ class Store:
         chunk_vector_dim = stored_vector_dim or self.embedder._vector_dim
         self.ChunkRecord: type[ChunkRecordBase] = create_chunk_model(chunk_vector_dim)
 
-        # Initialize tables (creates them if they don't exist)
-        await self._init_tables()
+        # Initialize tables (creates them if they don't exist). For an existing
+        # DB this raises MigrationRequiredError up front when migrations are
+        # pending, before creating any newly-introduced table.
+        await self._init_tables(is_new_db)
 
         # Checkout tables to historical state if before is specified
         if self._before is not None:
             await self._checkout_tables_before(self._before)
 
-        # Set version for new databases, check migrations for existing ones
-        if is_new_db:
-            if not self._read_only:
-                await self._set_initial_version()
-        elif not self._skip_migration_check:
-            await self._check_migrations()
+        # Set version for new databases.
+        if is_new_db and not self._read_only:
+            await self._set_initial_version()
 
         # Validate config compatibility after connection is established
         if not self._skip_validation:
@@ -493,6 +506,7 @@ class Store:
                 retention = timedelta(seconds=retention_seconds)
                 for table in [
                     self.documents_table,
+                    self.document_meta_table,
                     self.chunks_table,
                     self.document_items_table,
                     self.settings_table,
@@ -553,9 +567,23 @@ class Store:
         settings_repo = SettingsRepository(self)
         await settings_repo.validate_config_compatibility()
 
-    async def _init_tables(self):
+    async def _init_tables(self, is_new_db: bool):
         """Initialize database tables (create if they don't exist)."""
         existing_tables = (await self.db.list_tables()).tables
+
+        # Surface pending migrations BEFORE creating any newly-introduced table.
+        # Otherwise opening a legacy DB would either mutate it (creating an empty
+        # document_meta on open) or raise the wrong ReadOnlyError instead of
+        # telling the user to run `haiku-rag migrate`. The settings table exists
+        # on any non-new DB, which is all _check_migrations needs.
+        if (
+            not is_new_db
+            and not self._skip_migration_check
+            and "settings" in existing_tables
+        ):
+            self.settings_table = await self.db.open_table("settings")
+            await self._check_migrations()
+
         missing_tables = set(REQUIRED_TABLES) - set(existing_tables)
 
         if missing_tables and self._read_only:
@@ -572,6 +600,22 @@ class Store:
                 "documents", schema=get_documents_arrow_schema()
             )
 
+        # Create or open document_meta table (mutable attributes kept out of the
+        # blob-bearing documents row). Indexed by document_id and uri — both are
+        # hot look-up keys (get_by_id, get_by_uri).
+        if "document_meta" in existing_tables:
+            self.document_meta_table = await self.db.open_table("document_meta")
+        else:
+            self.document_meta_table = await self.db.create_table(
+                "document_meta", schema=DocumentMetaRecord
+            )
+            await self.document_meta_table.create_index(
+                "document_id", config=BTree(), replace=True
+            )
+            await self.document_meta_table.create_index(
+                "uri", config=BTree(), replace=True
+            )
+
         # Create or open chunks table
         if "chunks" in existing_tables:
             self.chunks_table = await self.db.open_table("chunks")
@@ -748,6 +792,7 @@ class Store:
         """Capture current versions of key tables for rollback using LanceDB's API."""
         return {
             "documents": await self.documents_table.version(),
+            "document_meta": await self.document_meta_table.version(),
             "chunks": await self.chunks_table.version(),
             "document_items": await self.document_items_table.version(),
             "settings": await self.settings_table.version(),
@@ -761,6 +806,7 @@ class Store:
         """
         self._assert_writable()
         await self.documents_table.restore(int(versions["documents"]))
+        await self.document_meta_table.restore(int(versions["document_meta"]))
         await self.chunks_table.restore(int(versions["chunks"]))
         await self.document_items_table.restore(int(versions["document_items"]))
         await self.settings_table.restore(int(versions["settings"]))
@@ -786,6 +832,7 @@ class Store:
 
         tables = [
             ("documents", self.documents_table),
+            ("document_meta", self.document_meta_table),
             ("chunks", self.chunks_table),
             ("document_items", self.document_items_table),
             ("settings", self.settings_table),
@@ -838,6 +885,7 @@ class Store:
         """
         table_map = {
             "documents": self.documents_table,
+            "document_meta": self.document_meta_table,
             "chunks": self.chunks_table,
             "document_items": self.document_items_table,
             "settings": self.settings_table,

haiku_rag_slim/haiku/rag/store/repositories/chunk.py

@@ -272,14 +272,14 @@ class ChunkRepository:
             # filter in pandas, head(limit)) silently under-returned
             # whenever the top-N window lacked `limit` matching chunks.
             docs_df = await (
-                self.store.documents_table.query()
-                .select(["id"])
+                self.store.document_meta_table.query()
+                .select(["document_id"])
                 .where(filter)
                 .to_pandas()
             )
             if docs_df.empty:
                 return []
-            id_list = ", ".join(f"'{d}'" for d in docs_df["id"])
+            id_list = ", ".join(f"'{d}'" for d in docs_df["document_id"])
             chunk_filter = f"document_id IN ({id_list})"
 
         if query_vector is not None:
@@ -344,11 +344,11 @@ class ChunkRepository:
 
         results = await query_to_pydantic(query, self.store.ChunkRecord)
 
-        # Get document info (only metadata columns, skip content/docling blobs)
+        # Get document info from the mutable attributes table
         doc_rows = await (
-            self.store.documents_table.query()
-            .select(["id", "uri", "title", "metadata"])
-            .where(f"id = '{document_id}'")
+            self.store.document_meta_table.query()
+            .select(["document_id", "uri", "title", "metadata"])
+            .where(f"document_id = '{document_id}'")
             .limit(1)
             .to_list()
         )
@@ -504,14 +504,14 @@ class ChunkRepository:
         documents_map: dict[str, dict] = {}
         if document_ids:
             id_list = "', '".join(document_ids)
-            where_clause = f"id IN ('{id_list}')"
+            where_clause = f"document_id IN ('{id_list}')"
             doc_rows = await (
-                self.store.documents_table.query()
-                .select(["id", "uri", "title", "metadata"])
+                self.store.document_meta_table.query()
+                .select(["document_id", "uri", "title", "metadata"])
                 .where(where_clause)
                 .to_list()
             )
-            documents_map = {str(row["id"]): row for row in doc_rows}
+            documents_map = {str(row["document_id"]): row for row in doc_rows}
 
         # Build final results with document info
         chunks_with_scores = []

haiku_rag_slim/haiku/rag/store/repositories/document.py

@@ -6,6 +6,7 @@ from uuid import uuid4
 from lancedb.index import BTree
 
 from haiku.rag.store.engine import (
+    DocumentMetaRecord,
     DocumentRecord,
     Store,
     get_documents_arrow_schema,
@@ -16,7 +17,20 @@ from haiku.rag.utils import escape_sql_string
 
 
 class DocumentRepository:
-    """Repository for Document operations."""
+    """Repository for Document operations.
+
+    A document is stored across two tables with a strict invariant: every
+    `documents` row (id, content, docling blobs — write-once) has exactly one
+    matching `document_meta` row (uri, title, metadata, timestamps — mutable),
+    keyed by `document_id`. The mutable attributes never live in `documents`,
+    so metadata/title/source_revision updates (`update_meta`) rewrite only the
+    small meta row and never the multi-MB docling blob.
+
+    To preserve the invariant: `create` writes meta then documents and deletes
+    the meta row if the documents write fails; `update_meta` updates matched
+    rows only (no insert — an insert on a missing id would create a ghost
+    surfaced by `list_all`/`count`); `delete` removes both rows.
+    """
 
     def __init__(self, store: Store) -> None:
         self.store = store
@@ -43,45 +57,61 @@ class DocumentRepository:
             self._document_item_repository = DocumentItemRepository(self.store)
         return self._document_item_repository
 
-    def _record_to_document(self, record: DocumentRecord) -> Document:
-        """Convert a DocumentRecord to a Document model."""
+    def _merge_to_document(
+        self, doc: DocumentRecord, meta: DocumentMetaRecord | None
+    ) -> Document:
+        """Merge a `documents` record (content+blobs) with its `document_meta`
+        record (uri/title/metadata/timestamps) into a Document."""
+        created = meta.created_at if meta else ""
+        updated = meta.updated_at if meta else ""
         return Document(
-            id=record.id,
-            content=record.content,
-            uri=record.uri,
-            title=record.title,
-            metadata=json.loads(record.metadata),
-            docling_document=record.docling_document,
-            docling_pages=record.docling_pages,
-            docling_version=record.docling_version,
-            created_at=datetime.fromisoformat(record.created_at)
-            if record.created_at
-            else datetime.now(),
-            updated_at=datetime.fromisoformat(record.updated_at)
-            if record.updated_at
-            else datetime.now(),
+            id=doc.id,
+            content=doc.content,
+            uri=meta.uri if meta else None,
+            title=meta.title if meta else None,
+            metadata=json.loads(meta.metadata) if meta else {},
+            docling_document=doc.docling_document,
+            docling_pages=doc.docling_pages,
+            docling_version=doc.docling_version,
+            created_at=datetime.fromisoformat(created) if created else datetime.now(),
+            updated_at=datetime.fromisoformat(updated) if updated else datetime.now(),
         )
 
-    def _to_record(
+    def _to_documents_record(self, entity: Document, doc_id: str) -> DocumentRecord:
+        return DocumentRecord(
+            id=doc_id,
+            content=entity.content,
+            docling_document=entity.docling_document,
+            docling_pages=entity.docling_pages,
+            docling_version=entity.docling_version,
+        )
+
+    def _to_meta_record(
         self,
         entity: Document,
         doc_id: str,
         created_at: str,
         updated_at: str,
-    ) -> DocumentRecord:
-        return DocumentRecord(
-            id=doc_id,
-            content=entity.content,
+    ) -> DocumentMetaRecord:
+        return DocumentMetaRecord(
+            document_id=doc_id,
             uri=entity.uri,
             title=entity.title,
             metadata=json.dumps(entity.metadata),
-            docling_document=entity.docling_document,
-            docling_pages=entity.docling_pages,
-            docling_version=entity.docling_version,
             created_at=created_at,
             updated_at=updated_at,
         )
 
+    async def _meta_by_id(self, doc_id: str) -> DocumentMetaRecord | None:
+        safe_id = escape_sql_string(doc_id)
+        results = await query_to_pydantic(
+            self.store.document_meta_table.query()
+            .where(f"document_id = '{safe_id}'")
+            .limit(1),
+            DocumentMetaRecord,
+        )
+        return results[0] if results else None
+
     @overload
     async def create(self, entity: Document) -> Document: ...
 
@@ -97,12 +127,29 @@ class DocumentRepository:
         """
         self.store._assert_writable()
 
+        # document_meta is written before documents so the documents row write
+        # is the commit point: time-travel to any documents version always sees
+        # the matching (earlier-written) document_meta row. If the documents
+        # write then fails, delete just the rows we added (not a table-version
+        # restore, which would clobber a concurrent writer's meta write) so a
+        # failed create can't leave a ghost row that list_all/count (which read
+        # document_meta) would surface.
         if isinstance(entity, Document):
             doc_id = str(uuid4())
             now = datetime.now().isoformat()
-            await self.store.documents_table.add(
-                [self._to_record(entity, doc_id, now, now)]
+            await self.store.document_meta_table.add(
+                [self._to_meta_record(entity, doc_id, now, now)]
             )
+            try:
+                await self.store.documents_table.add(
+                    [self._to_documents_record(entity, doc_id)]
+                )
+            except Exception:
+                safe_id = escape_sql_string(doc_id)
+                await self.store.document_meta_table.delete(
+                    f"document_id = '{safe_id}'"
+                )
+                raise
             entity.id = doc_id
             entity.created_at = datetime.fromisoformat(now)
             entity.updated_at = datetime.fromisoformat(now)
@@ -114,15 +161,25 @@ class DocumentRepository:
 
         now = datetime.now().isoformat()
         created_at = datetime.fromisoformat(now)
-        records = []
+        doc_records = []
+        meta_records = []
+        doc_ids = []
         for document in documents:
             doc_id = str(uuid4())
-            records.append(self._to_record(document, doc_id, now, now))
+            doc_ids.append(doc_id)
+            doc_records.append(self._to_documents_record(document, doc_id))
+            meta_records.append(self._to_meta_record(document, doc_id, now, now))
             document.id = doc_id
             document.created_at = created_at
             document.updated_at = created_at
 
-        await self.store.documents_table.add(records)
+        await self.store.document_meta_table.add(meta_records)
+        try:
+            await self.store.documents_table.add(doc_records)
+        except Exception:
+            ids = ", ".join(f"'{escape_sql_string(d)}'" for d in doc_ids)
+            await self.store.document_meta_table.delete(f"document_id IN ({ids})")
+            raise
         return documents
 
     async def get_by_id(self, entity_id: str) -> Document | None:
@@ -136,7 +193,8 @@ class DocumentRepository:
         if not results:
             return None
 
-        return self._record_to_document(results[0])
+        meta = await self._meta_by_id(entity_id)
+        return self._merge_to_document(results[0], meta)
 
     async def get_content(self, entity_id: str) -> str | None:
         """Get only the text content of a document (skips docling blobs)."""
@@ -197,28 +255,43 @@ class DocumentRepository:
             docling_pages=row.get("docling_pages"),
         )
 
-    async def update(self, entity: Document) -> Document:
-        """Update an existing document."""
+    async def update_meta(self, entity: Document) -> Document:
+        """Update only the mutable attributes (uri/title/metadata/updated_at) in
+        `document_meta`. Does NOT touch the `documents` row, so the multi-MB
+        docling blob is never rewritten — this is the blob-bloat fix for
+        metadata/title/source_revision changes."""
         self.store._assert_writable()
-
         assert entity.id, "Document ID is required for update"
 
-        # Update timestamp
         now = datetime.now().isoformat()
         entity.updated_at = datetime.fromisoformat(now)
-
-        record = self._to_record(
-            entity,
-            entity.id,
-            entity.created_at.isoformat() if entity.created_at else now,
-            now,
-        )
+        created = entity.created_at.isoformat() if entity.created_at else now
+        record = self._to_meta_record(entity, entity.id, created, now)
+        # Update only — no insert. Every real document has a document_meta row
+        # from create()/migration; inserting on no-match would manufacture a
+        # ghost row (visible to list_all/count) for an id with no documents row.
         await (
-            self.store.documents_table.merge_insert("id")
+            self.store.document_meta_table.merge_insert("document_id")
             .when_matched_update_all()
             .execute([record])
         )
+        return entity
 
+    async def update(self, entity: Document) -> Document:
+        """Update a document's content+blobs (genuine re-conversion) and its
+        mutable attributes. Rewrites the `documents` row, so use only when the
+        docling content actually changed; for metadata/title-only changes use
+        `update_meta`."""
+        self.store._assert_writable()
+        assert entity.id, "Document ID is required for update"
+
+        doc_record = self._to_documents_record(entity, entity.id)
+        await (
+            self.store.documents_table.merge_insert("id")
+            .when_matched_update_all()
+            .execute([doc_record])
+        )
+        await self.update_meta(entity)
         return entity
 
     async def delete(self, entity_id: str) -> bool:
@@ -234,13 +307,12 @@ class DocumentRepository:
         await self.chunk_repository.delete_by_document_id(entity_id)
         await self.document_item_repository.delete_by_document_id(entity_id)
 
-        # Delete the document
+        # Delete the document row, its mutable attributes
         safe_id = escape_sql_string(entity_id)
         await self.store.documents_table.delete(f"id = '{safe_id}'")
+        await self.store.document_meta_table.delete(f"document_id = '{safe_id}'")
         return True
 
-    _LISTING_COLUMNS = ["id", "title", "uri", "metadata", "created_at", "updated_at"]
-
     async def list_all(
         self,
         limit: int | None = None,
@@ -250,20 +322,21 @@ class DocumentRepository:
     ) -> list[Document]:
         """List all documents with optional pagination and filtering.
 
+        Listing reads `document_meta` (uri/title/metadata/timestamps); the
+        SQL `filter` is evaluated against those columns. When `include_content`
+        is set, the content+blob row is loaded from `documents` and merged in.
+
         Args:
             limit: Maximum number of documents to return.
             offset: Number of documents to skip.
-            filter: Optional SQL WHERE clause to filter documents.
-            include_content: Whether to load content and docling_document.
-                Defaults to False to avoid loading large blobs for listing.
+            filter: Optional SQL WHERE clause over document_meta columns.
+            include_content: Whether to also load content and docling blobs.
 
         Returns:
             List of Document instances matching the criteria.
         """
-        query = self.store.documents_table.query()
+        query = self.store.document_meta_table.query()
 
-        if not include_content:
-            query = query.select(self._LISTING_COLUMNS)
         if filter is not None:
             query = query.where(filter)
         if offset is not None:
@@ -271,50 +344,56 @@ class DocumentRepository:
         if limit is not None:
             query = query.limit(limit)
 
-        if include_content:
-            results = await query_to_pydantic(query, DocumentRecord)
-            return [self._record_to_document(doc) for doc in results]
+        meta_records = await query_to_pydantic(query, DocumentMetaRecord)
 
-        return [
-            Document(
-                id=row["id"],
-                content="",
-                title=row.get("title"),
-                uri=row.get("uri"),
-                metadata=json.loads(row.get("metadata", "{}")),
-                created_at=datetime.fromisoformat(row["created_at"])
-                if row.get("created_at")
-                else datetime.now(),
-                updated_at=datetime.fromisoformat(row["updated_at"])
-                if row.get("updated_at")
-                else datetime.now(),
+        if not include_content:
+            return [
+                self._merge_to_document(DocumentRecord(id=m.document_id, content=""), m)
+                for m in meta_records
+            ]
+
+        documents: list[Document] = []
+        for meta in meta_records:
+            safe_id = escape_sql_string(meta.document_id)
+            doc_results = await query_to_pydantic(
+                self.store.documents_table.query().where(f"id = '{safe_id}'").limit(1),
+                DocumentRecord,
             )
-            for row in await query.to_list()
-        ]
+            doc_record = (
+                doc_results[0]
+                if doc_results
+                else DocumentRecord(id=meta.document_id, content="")
+            )
+            documents.append(self._merge_to_document(doc_record, meta))
+        return documents
 
     async def count(self, filter: str | None = None) -> int:
-        """Count documents with optional filtering.
-
-        Args:
-            filter: Optional SQL WHERE clause to filter documents.
-
-        Returns:
-            Number of documents matching the criteria.
-        """
-        return await self.store.documents_table.count_rows(filter=filter)
+        """Count documents with optional filtering (over document_meta columns)."""
+        return await self.store.document_meta_table.count_rows(filter=filter)
 
     async def get_by_uri(self, uri: str) -> Document | None:
-        """Get a document by its URI."""
+        """Get a document by its URI (resolved via document_meta)."""
         escaped_uri = escape_sql_string(uri)
-        results = await query_to_pydantic(
-            self.store.documents_table.query().where(f"uri = '{escaped_uri}'").limit(1),
-            DocumentRecord,
+        meta_results = await query_to_pydantic(
+            self.store.document_meta_table.query()
+            .where(f"uri = '{escaped_uri}'")
+            .limit(1),
+            DocumentMetaRecord,
         )
 
-        if not results:
+        if not meta_results:
             return None
 
-        return self._record_to_document(results[0])
+        meta = meta_results[0]
+        safe_id = escape_sql_string(meta.document_id)
+        doc_results = await query_to_pydantic(
+            self.store.documents_table.query().where(f"id = '{safe_id}'").limit(1),
+            DocumentRecord,
+        )
+        if not doc_results:
+            return None
+
+        return self._merge_to_document(doc_results[0], meta)
 
     async def delete_all(self) -> None:
         """Delete all documents from the database."""
@@ -344,8 +423,18 @@ class DocumentRepository:
             )
         )
         if count > 0:
-            # Drop and recreate table to clear all data
+            # Drop and recreate tables to clear all data
             await self.store.db.drop_table("documents")
             self.store.documents_table = await self.store.db.create_table(
                 "documents", schema=get_documents_arrow_schema()
             )
+            await self.store.db.drop_table("document_meta")
+            self.store.document_meta_table = await self.store.db.create_table(
+                "document_meta", schema=DocumentMetaRecord
+            )
+            await self.store.document_meta_table.create_index(
+                "document_id", config=BTree(), replace=True
+            )
+            await self.store.document_meta_table.create_index(
+                "uri", config=BTree(), replace=True
+            )

haiku_rag_slim/haiku/rag/store/upgrades/__init__.py

@@ -93,6 +93,9 @@ from haiku.rag.store.upgrades.v0_48_0 import (
 from haiku.rag.store.upgrades.v0_50_0 import (
     upgrade_canonical_metadata_keys as upgrade_0_50_0_canonical_metadata_keys,
 )
+from haiku.rag.store.upgrades.v0_57_0 import (
+    upgrade_split_document_meta as upgrade_0_57_0_split_document_meta,
+)
 
 upgrades.append(upgrade_0_20_0_docling)
 upgrades.append(upgrade_0_23_1_contextualize)
@@ -102,3 +105,4 @@ upgrades.append(upgrade_0_40_0_document_items)
 upgrades.append(upgrade_0_45_0_extract_picture_bytes)
 upgrades.append(upgrade_0_48_0_heading_hierarchy)
 upgrades.append(upgrade_0_50_0_canonical_metadata_keys)
+upgrades.append(upgrade_0_57_0_split_document_meta)

haiku_rag_slim/haiku/rag/store/upgrades/v0_57_0.py

@@ -0,0 +1,98 @@
+import logging
+import shutil
+
+from haiku.rag.store.engine import DocumentMetaRecord, Store
+from haiku.rag.store.upgrades import Upgrade
+
+logger = logging.getLogger(__name__)
+
+_LEGACY_COLUMNS = ["uri", "title", "metadata", "created_at", "updated_at"]
+
+
+async def _apply_split_document_meta(store: Store) -> None:
+    """Move the mutable document attributes (uri/title/metadata/created_at/
+    updated_at) out of the blob-bearing `documents` row into `document_meta`.
+
+    After this, a metadata/title/source_revision update writes only the small
+    `document_meta` row instead of rewriting the multi-MB docling blob. The
+    blobs (content, docling_document, docling_pages) stay in `documents`.
+
+    The `document_meta` table itself is created on open by `_init_tables`; this
+    migration populates it and drops the now-relocated columns from `documents`.
+    Idempotent: a re-run after a partial failure skips already-moved rows and
+    skips the column drop if the columns are already gone.
+    """
+    schema = await store.documents_table.schema()
+    present = [c for c in _LEGACY_COLUMNS if c in schema.names]
+
+    if not present:
+        logger.info("documents already split; nothing to move")
+        return
+
+    # Resume support: skip documents whose meta row already exists.
+    existing_meta = {
+        row["document_id"]
+        for row in await store.document_meta_table.query()
+        .select(["document_id"])
+        .to_list()
+    }
+
+    rows = await store.documents_table.query().select(["id", *present]).to_list()
+    records = []
+    for row in rows:
+        if row["id"] in existing_meta:
+            continue
+        meta = row.get("metadata")
+        records.append(
+            DocumentMetaRecord(
+                document_id=row["id"],
+                uri=row.get("uri"),
+                title=row.get("title"),
+                metadata=meta if isinstance(meta, str) and meta else "{}",
+                created_at=row.get("created_at") or "",
+                updated_at=row.get("updated_at") or "",
+            )
+        )
+    if records:
+        logger.info(
+            "Moving attributes for %d document(s) into document_meta", len(records)
+        )
+        await store.document_meta_table.add(records)
+
+    # Drop the relocated columns from documents (a metadata operation — no row
+    # rewrite, so it is cheap and safe even on a near-full disk).
+    logger.info("Dropping %s from documents", ", ".join(present))
+    await store.documents_table.drop_columns(present)
+
+    # Reclaim the bloat accumulated before the fix (superseded docling rows from
+    # past metadata churn). retention=0 is safe ONLY because migrate is
+    # exclusive/single-writer; this must never become normal ingester behaviour.
+    # Compaction rewrites the live blobs once (transient peak ~= current size +
+    # one compacted copy), so skip it (best-effort) when free disk cannot cover
+    # that — the split is already done; the user can run `haiku-rag vacuum`.
+    try:
+        # lancedb's .stats() stub claims TableStatistics but returns a plain dict.
+        stats: dict = await store.documents_table.stats()  # type: ignore[assignment]  # ty: ignore[invalid-assignment]
+        live_bytes = int(stats.get("total_bytes", 0))
+    except Exception:
+        live_bytes = 0
+    free_bytes = shutil.disk_usage(store.db_path).free
+    if live_bytes and free_bytes < live_bytes:
+        logger.warning(
+            "Skipping post-migration vacuum: need ~%.2f GB free to compact the "
+            "documents table, have %.2f GB. Run `haiku-rag vacuum` once you have "
+            "space to reclaim the accumulated bloat.",
+            live_bytes / 1e9,
+            free_bytes / 1e9,
+        )
+        return
+
+    logger.info("Vacuuming to reclaim accumulated document bloat")
+    await store.vacuum(retention_seconds=0)
+
+
+upgrade_split_document_meta = Upgrade(
+    version="0.57.0",
+    apply=_apply_split_document_meta,
+    description="Move mutable document attributes into the document_meta table",
+)

tests/store/legacy_documents.py

@@ -0,0 +1,56 @@
+"""Helpers to seed a `documents` table in its pre-0.57 shape.
+
+Before the document_meta split (v0.57.0), the `documents` table carried
+`uri/title/metadata/created_at/updated_at` alongside the content+blobs. The
+migration-chain tests need to reproduce that legacy layout so the older
+migrations (which read `documents.metadata`, etc.) and v0.57.0 itself have the
+columns they operate on.
+"""
+
+from uuid import uuid4
+
+import pyarrow as pa
+from lancedb.pydantic import LanceModel
+from pydantic import Field
+
+from haiku.rag.store.engine import Store
+
+
+class LegacyDocumentRecord(LanceModel):
+    """The pre-0.57 `documents` record (mutable attributes still inline)."""
+
+    id: str = Field(default_factory=lambda: str(uuid4()))
+    content: str
+    uri: str | None = None
+    title: str | None = None
+    metadata: str = Field(default="{}")
+    docling_document: bytes | None = None
+    docling_pages: bytes | None = None
+    docling_version: str | None = None
+    created_at: str = Field(default_factory=lambda: "")
+    updated_at: str = Field(default_factory=lambda: "")
+
+
+def legacy_documents_schema() -> pa.Schema:
+    base = LegacyDocumentRecord.to_arrow_schema()
+    large_binary_columns = {"docling_document", "docling_pages"}
+    return pa.schema(
+        [
+            pa.field(f.name, pa.large_binary()) if f.name in large_binary_columns else f
+            for f in base
+        ]
+    )
+
+
+async def seed_legacy_documents(
+    store: Store, records: list[LegacyDocumentRecord]
+) -> None:
+    """Recreate the `documents` table with the pre-0.57 schema and add records,
+    simulating a database created before the document_meta split."""
+    if "documents" in (await store.db.list_tables()).tables:
+        await store.db.drop_table("documents")
+    store.documents_table = await store.db.create_table(
+        "documents", schema=legacy_documents_schema()
+    )
+    if records:
+        await store.documents_table.add(records)

tests/store/test_document_items.py

@@ -394,6 +394,7 @@ class TestDocumentItemMigration:
         """Test that the v0.40.0 migration populates items for pre-existing documents."""
         from haiku.rag.store.compression import compress_docling_split
         from haiku.rag.store.engine import DocumentRecord
+        from haiku.rag.store.upgrades.v0_40_0 import _apply_populate_document_items
 
         docling_doc = _make_docling_doc()
         json_str = docling_doc.model_dump_json()
@@ -405,7 +406,6 @@ class TestDocumentItemMigration:
             doc_record = DocumentRecord(
                 id="test-doc-1",
                 content="test content",
-                uri="test://doc",
                 docling_document=structure,
                 docling_pages=pages,
                 docling_version=docling_doc.version,
@@ -415,12 +415,11 @@ class TestDocumentItemMigration:
             # Verify no items exist yet
             assert await store.document_items_table.count_rows() == 0
 
-        # Re-open with skip_migration_check and run migration
+        # Re-open and apply the v0.40.0 migration in isolation (the full chain
+        # would also run later migrations that touch documents.metadata, absent
+        # from this docling-only fixture).
         async with Store(temp_db_path, skip_migration_check=True) as store:
-            applied = await store.migrate()
-
-            # Should have applied the v0.40.0 migration
-            assert any("document_items" in desc for desc in applied)
+            await _apply_populate_document_items(store)
 
             # Items should now exist
             item_count = await store.document_items_table.count_rows(
@@ -442,6 +441,7 @@ class TestDocumentItemMigration:
     async def test_migration_skips_documents_without_docling(self, temp_db_path):
         """Test that migration handles documents without docling data."""
         from haiku.rag.store.engine import DocumentRecord
+        from haiku.rag.store.upgrades.v0_40_0 import _apply_populate_document_items
 
         async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
             await store.set_haiku_version("0.39.0")
@@ -452,7 +452,7 @@ class TestDocumentItemMigration:
             await store.documents_table.add([doc_record])
 
         async with Store(temp_db_path, skip_migration_check=True) as store:
-            await store.migrate()
+            await _apply_populate_document_items(store)
 
             # No items should have been created
             assert await store.document_items_table.count_rows() == 0
@@ -705,6 +705,7 @@ class TestPictureDataMigrationBackfill:
 
         from haiku.rag.store.compression import compress_json, decompress_json
         from haiku.rag.store.engine import DocumentItemRecord, DocumentRecord
+        from haiku.rag.store.upgrades.v0_45_0 import _apply_extract_picture_bytes
 
         fake_png = b"\x89PNG\r\n\x1a\nlegacy-picture-bytes-for-test"
         data_uri = "data:image/png;base64," + base64.b64encode(fake_png).decode("ascii")
@@ -756,8 +757,9 @@ class TestPictureDataMigrationBackfill:
             assert "picture_data" not in {f.name for f in schema_before}
 
         async with Store(temp_db_path, skip_migration_check=True) as store:
-            applied = await store.migrate()
-            assert any("picture" in d.lower() for d in applied)
+            # Apply the v0.45.0 migration in isolation (the full chain would also
+            # run later migrations that touch documents.metadata, absent here).
+            await _apply_extract_picture_bytes(store)
 
             # Column was added by the migration
             schema_after = await store.document_items_table.schema()

tests/store/test_document_meta_split.py

@@ -0,0 +1,108 @@
+import lancedb
+import pytest
+
+from haiku.rag.store.engine import Store
+from haiku.rag.store.exceptions import MigrationRequiredError
+from haiku.rag.store.models.document import Document
+from haiku.rag.store.repositories.document import DocumentRepository
+from tests.store.legacy_documents import (
+    LegacyDocumentRecord,
+    seed_legacy_documents,
+)
+
+
+@pytest.mark.asyncio
+async def test_create_rolls_back_meta_when_documents_write_fails(temp_db_path):
+    """A failed documents write must not leave an orphan document_meta row that
+    list_all/count would surface (they read document_meta). The rollback must be
+    targeted — it deletes only the failed row, leaving other documents intact."""
+    async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
+        repo = DocumentRepository(store)
+
+        # A pre-existing document that must survive the failed create's rollback.
+        good = await repo.create(Document(content="keep", uri="mem://keep"))
+        assert good.id is not None
+
+        original_add = store.documents_table.add
+
+        async def boom(*_args, **_kwargs):
+            raise RuntimeError("documents write failed")
+
+        store.documents_table.add = boom
+        with pytest.raises(RuntimeError, match="documents write failed"):
+            await repo.create(Document(content="x", uri="mem://ghost"))
+        store.documents_table.add = original_add
+
+        # The ghost's meta row was deleted; the good document is untouched.
+        assert await repo.count() == 1
+        assert [d.id for d in await repo.list_all()] == [good.id]
+        assert await store.document_meta_table.count_rows() == 1
+        assert await repo.get_by_uri("mem://ghost") is None
+        fetched = await repo.get_by_id(good.id)
+        assert fetched is not None and fetched.uri == "mem://keep"
+
+
+@pytest.mark.asyncio
+async def test_update_missing_id_does_not_create_ghost(temp_db_path):
+    """update()/update_meta() for an id with no documents row must not insert a
+    document_meta row — otherwise it would show up in list_all/count while
+    get_by_id returns None."""
+    async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
+        repo = DocumentRepository(store)
+
+        await repo.update(Document(id="missing", content="x", uri="u"))
+
+        assert await repo.count() == 0
+        assert await repo.list_all() == []
+        assert await store.documents_table.count_rows() == 0
+        assert await store.document_meta_table.count_rows() == 0
+        assert await repo.get_by_id("missing") is None
+
+
+@pytest.mark.asyncio
+async def test_opening_legacy_db_raises_migration_without_mutating(temp_db_path):
+    """Opening a pre-0.57 DB (no document_meta) must raise MigrationRequiredError
+    up front — in both writable and read-only mode — and must not mutate the DB
+    by creating the new table on open."""
+    async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
+        await seed_legacy_documents(
+            store,
+            [LegacyDocumentRecord(id="d", content="x", uri="u", metadata="{}")],
+        )
+        # A real pre-0.57 DB has no document_meta table.
+        await store.db.drop_table("document_meta")
+        await store.set_haiku_version("0.56.0")
+
+    # Writable open: pending migration surfaces before any table creation.
+    with pytest.raises(MigrationRequiredError):
+        async with Store(temp_db_path):
+            pass
+
+    # Read-only open: must also be MigrationRequiredError (not ReadOnlyError).
+    with pytest.raises(MigrationRequiredError):
+        async with Store(temp_db_path, read_only=True):
+            pass
+
+    # The failed opens did not create document_meta.
+    raw = await lancedb.connect_async(str(temp_db_path))
+    assert "document_meta" not in (await raw.list_tables()).tables
+
+
+@pytest.mark.asyncio
+async def test_migrate_creates_and_populates_document_meta(temp_db_path):
+    """The migrate path (skip_migration_check) still creates and fills
+    document_meta for a legacy DB."""
+    async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
+        await seed_legacy_documents(
+            store,
+            [LegacyDocumentRecord(id="d", content="x", uri="u", metadata="{}")],
+        )
+        await store.db.drop_table("document_meta")
+        await store.set_haiku_version("0.56.0")
+
+    async with Store(temp_db_path, skip_migration_check=True) as store:
+        await store.migrate()
+        assert "document_meta" in (await store.db.list_tables()).tables
+        repo = DocumentRepository(store)
+        doc = await repo.get_by_id("d")
+        assert doc is not None and doc.uri == "u"

tests/store/test_v0_48_0_migration.py

@@ -4,6 +4,7 @@ import pytest
 
 from haiku.rag.store.compression import compress_docling_split
 from haiku.rag.store.engine import DocumentItemRecord, DocumentRecord, Store
+from haiku.rag.store.upgrades.v0_48_0 import _apply_backfill_heading_hierarchy
 
 
 def _docling_with_levels():
@@ -58,8 +59,10 @@ class TestV0_48_0Migration:
             )
 
         async with Store(temp_db_path, skip_migration_check=True) as store:
-            applied = await store.migrate()
-            assert any("0.48.0" in d for d in applied)
+            # Apply the migration in isolation: store.migrate() would run the
+            # whole chain (incl. v0.50.0/v0.57.0 which touch documents.metadata,
+            # absent from this docling-only fixture).
+            await _apply_backfill_heading_hierarchy(store)
 
             rows = await (
                 store.document_items_table.query()
@@ -107,12 +110,8 @@ class TestV0_48_0Migration:
             )
 
         async with Store(temp_db_path, skip_migration_check=True) as store:
-            await store.migrate()
-
-            from haiku.rag.store.upgrades.v0_48_0 import (
-                _apply_backfill_heading_hierarchy,
-            )
-
+            # Apply twice to prove idempotency (in isolation from the chain).
+            await _apply_backfill_heading_hierarchy(store)
             await _apply_backfill_heading_hierarchy(store)
 
             rows = await (
@@ -144,7 +143,7 @@ class TestV0_48_0Migration:
             )
 
         async with Store(temp_db_path, skip_migration_check=True) as store:
-            await store.migrate()
+            await _apply_backfill_heading_hierarchy(store)
             rows = await (
                 store.document_items_table.query()
                 .where("document_id = 'plain'")

tests/store/test_v0_50_0_migration.py

@@ -2,19 +2,30 @@ import json
 
 import pytest
 
-from haiku.rag.store.engine import DocumentRecord, Store
+from haiku.rag.store.engine import Store
+from haiku.rag.store.upgrades.v0_50_0 import _apply_canonical_metadata_keys
+from tests.store.legacy_documents import (
+    LegacyDocumentRecord,
+    seed_legacy_documents,
+)
 
 
 @pytest.mark.asyncio
 class TestV0_50_0Migration:
-    """v0.50.0 normalises document.metadata to source-agnostic keys."""
+    """v0.50.0 normalises document.metadata to source-agnostic keys.
+
+    Applied in isolation against the pre-0.57 documents schema (metadata still
+    inline), so the assertions read documents.metadata directly. The full chain
+    (where v0.57.0 later relocates metadata to document_meta) is covered by the
+    v0.57.0 migration test.
+    """
 
     async def test_renames_etag_and_content_type(self, temp_db_path):
         async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
-            await store.set_haiku_version("0.48.1")
-            await store.documents_table.add(
+            await seed_legacy_documents(
+                store,
                 [
-                    DocumentRecord(
+                    LegacyDocumentRecord(
                         id="doc-s3",
                         content="x",
                         uri="s3://b/k",
@@ -26,7 +37,7 @@ class TestV0_50_0Migration:
                             }
                         ),
                     ),
-                    DocumentRecord(
+                    LegacyDocumentRecord(
                         id="doc-fs",
                         content="y",
                         uri="file:///tmp/x.md",
@@ -37,12 +48,10 @@ class TestV0_50_0Migration:
                             }
                         ),
                     ),
-                ]
+                ],
             )
 
-        async with Store(temp_db_path, skip_migration_check=True) as store:
-            applied = await store.migrate()
-            assert any("0.50.0" in d for d in applied)
+            await _apply_canonical_metadata_keys(store)
 
             rows = await store.documents_table.query().to_list()
             by_id = {r["id"]: json.loads(r["metadata"]) for r in rows}
@@ -59,10 +68,10 @@ class TestV0_50_0Migration:
 
     async def test_idempotent_on_already_migrated(self, temp_db_path):
         async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
-            await store.set_haiku_version("0.48.1")
-            await store.documents_table.add(
+            await seed_legacy_documents(
+                store,
                 [
-                    DocumentRecord(
+                    LegacyDocumentRecord(
                         id="d",
                         content="x",
                         uri="s3://b/k",
@@ -74,11 +83,10 @@ class TestV0_50_0Migration:
                             }
                         ),
                     )
-                ]
+                ],
             )
 
-        async with Store(temp_db_path, skip_migration_check=True) as store:
-            await store.migrate()
+            await _apply_canonical_metadata_keys(store)
             rows = await store.documents_table.query().to_list()
             assert json.loads(rows[0]["metadata"]) == {
                 "source_revision": "abc",
@@ -91,14 +99,11 @@ class TestV0_50_0Migration:
         quoted-key form. Values that happen to contain the substring `etag` and
         composite key names like `my_etag_key` must not get rewritten."""
         async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
-            await store.set_haiku_version("0.48.1")
-            await store.documents_table.add(
+            await seed_legacy_documents(
+                store,
                 [
-                    # `etag` only appears as a VALUE — no `etag` key. Either
-                    # the LIKE excludes it (no work), or it pulls it in and
-                    # _normalize_metadata leaves it alone. Either way the row
-                    # must end up unchanged.
-                    DocumentRecord(
+                    # `etag` only appears as a VALUE — no `etag` key.
+                    LegacyDocumentRecord(
                         id="value-only",
                         content="x",
                         uri="u1",
@@ -110,8 +115,7 @@ class TestV0_50_0Migration:
                         ),
                     ),
                     # A composite key containing `etag` but not equal to it.
-                    # Must not be rewritten.
-                    DocumentRecord(
+                    LegacyDocumentRecord(
                         id="composite-key",
                         content="x",
                         uri="u2",
@@ -122,11 +126,10 @@ class TestV0_50_0Migration:
                             }
                         ),
                     ),
-                ]
+                ],
             )
 
-        async with Store(temp_db_path, skip_migration_check=True) as store:
-            await store.migrate()
+            await _apply_canonical_metadata_keys(store)
             rows = await store.documents_table.query().to_list()
             by_id = {r["id"]: json.loads(r["metadata"]) for r in rows}
 
@@ -144,30 +147,28 @@ class TestV0_50_0Migration:
         migration: it's logged and skipped, and well-formed rows alongside it
         still get rewritten. The bad row's metadata is left exactly as-is."""
         async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
-            await store.set_haiku_version("0.48.1")
-            await store.documents_table.add(
+            await seed_legacy_documents(
+                store,
                 [
-                    # Contains the substring `"etag"` so the WHERE LIKE pulls
-                    # it in, but it's not valid JSON — json.loads fails.
-                    DocumentRecord(
+                    # Contains the substring `"etag"` so the WHERE LIKE pulls it
+                    # in, but it's not valid JSON — json.loads fails.
+                    LegacyDocumentRecord(
                         id="bad",
                         content="x",
                         uri="u1",
                         metadata='{"etag": broken',
                     ),
-                    DocumentRecord(
+                    LegacyDocumentRecord(
                         id="good",
                         content="x",
                         uri="u2",
                         metadata=json.dumps({"etag": "abc"}),
                     ),
-                ]
+                ],
             )
 
-        async with Store(temp_db_path, skip_migration_check=True) as store:
             # Must not raise.
-            applied = await store.migrate()
-            assert any("0.50.0" in d for d in applied)
+            await _apply_canonical_metadata_keys(store)
 
             rows = await store.documents_table.query().to_list()
             by_id = {r["id"]: r["metadata"] for r in rows}
@@ -179,10 +180,10 @@ class TestV0_50_0Migration:
         """If both legacy and canonical keys are present, the canonical wins
         and the legacy is dropped — defends against partial-migration states."""
         async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
-            await store.set_haiku_version("0.48.1")
-            await store.documents_table.add(
+            await seed_legacy_documents(
+                store,
                 [
-                    DocumentRecord(
+                    LegacyDocumentRecord(
                         id="d",
                         content="x",
                         uri="s3://b/k",
@@ -195,11 +196,10 @@ class TestV0_50_0Migration:
                             }
                         ),
                     )
-                ]
+                ],
             )
 
-        async with Store(temp_db_path, skip_migration_check=True) as store:
-            await store.migrate()
+            await _apply_canonical_metadata_keys(store)
             rows = await store.documents_table.query().to_list()
             meta = json.loads(rows[0]["metadata"])
             assert meta == {

tests/store/test_v0_57_0_migration.py

@@ -0,0 +1,98 @@
+import json
+
+import pytest
+
+from haiku.rag.store.engine import Store
+from haiku.rag.store.repositories.document import DocumentRepository
+from haiku.rag.store.upgrades.v0_57_0 import _apply_split_document_meta
+from tests.store.legacy_documents import (
+    LegacyDocumentRecord,
+    seed_legacy_documents,
+)
+
+_LEGACY_COLUMNS = {"uri", "title", "metadata", "created_at", "updated_at"}
+
+
+@pytest.mark.asyncio
+class TestV0_57_0Migration:
+    """v0.57.0 moves mutable attributes out of the documents row into
+    document_meta so metadata/title updates stop rewriting the docling blob."""
+
+    async def test_moves_attributes_and_drops_columns(self, temp_db_path):
+        async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
+            await seed_legacy_documents(
+                store,
+                [
+                    LegacyDocumentRecord(
+                        id="doc-1",
+                        content="body one",
+                        uri="s3://b/one",
+                        title="One",
+                        metadata=json.dumps({"source_revision": "r1", "md5": "a"}),
+                        docling_document=b"structure-blob-1",
+                        docling_pages=b"pages-blob-1",
+                        docling_version="1.10.0",
+                        created_at="2026-01-01T00:00:00",
+                        updated_at="2026-01-02T00:00:00",
+                    )
+                ],
+            )
+            await store.set_haiku_version("0.56.0")
+
+        async with Store(temp_db_path, skip_migration_check=True) as store:
+            applied = await store.migrate()
+            assert any("0.57.0" in d for d in applied)
+
+            # Legacy columns dropped from documents; blobs stay.
+            doc_names = {f.name for f in await store.documents_table.schema()}
+            assert _LEGACY_COLUMNS.isdisjoint(doc_names)
+            assert {"id", "content", "docling_document", "docling_pages"} <= doc_names
+
+            # Attributes landed in document_meta.
+            meta_rows = await store.document_meta_table.query().to_list()
+            assert len(meta_rows) == 1
+            row = meta_rows[0]
+            assert row["document_id"] == "doc-1"
+            assert row["uri"] == "s3://b/one"
+            assert row["title"] == "One"
+            assert json.loads(row["metadata"]) == {"source_revision": "r1", "md5": "a"}
+
+            # Full hydration still works (content + metadata + blobs intact).
+            repo = DocumentRepository(store)
+            doc = await repo.get_by_id("doc-1")
+            assert doc is not None
+            assert doc.content == "body one"
+            assert doc.uri == "s3://b/one"
+            assert doc.title == "One"
+            assert doc.metadata == {"source_revision": "r1", "md5": "a"}
+            assert doc.docling_document == b"structure-blob-1"
+            assert doc.docling_pages == b"pages-blob-1"
+            assert doc.docling_version == "1.10.0"
+
+            # Lookup by uri (resolved via document_meta) works too.
+            by_uri = await repo.get_by_uri("s3://b/one")
+            assert by_uri is not None and by_uri.id == "doc-1"
+
+    async def test_idempotent_on_already_split(self, temp_db_path):
+        async with Store(temp_db_path, create=True, skip_migration_check=True) as store:
+            await seed_legacy_documents(
+                store,
+                [
+                    LegacyDocumentRecord(
+                        id="doc-1",
+                        content="body",
+                        uri="u1",
+                        metadata=json.dumps({"source_revision": "r1"}),
+                    )
+                ],
+            )
+            await store.set_haiku_version("0.56.0")
+
+        async with Store(temp_db_path, skip_migration_check=True) as store:
+            await store.migrate()
+            # Re-applying must be a no-op (documents already split).
+            await _apply_split_document_meta(store)
+
+            meta_rows = await store.document_meta_table.query().to_list()
+            assert len(meta_rows) == 1
+            assert meta_rows[0]["document_id"] == "doc-1"

tests/test_client.py

@@ -907,6 +907,52 @@ async def test_client_update_document_replaces_rows_with_bounded_versions(
         assert stored_items[0].text == "Updated body"
 
 
+async def test_metadata_only_update_does_not_advance_documents_table(temp_db_path):
+    """Metadata/title-only updates must not rewrite the heavy documents row.
+
+    This is the blob-bloat fix: source_revision rolling on every ingester sweep
+    used to rewrite the multi-MB docling row each time. Mutable attributes now
+    live in document_meta, so the documents table version must stay frozen while
+    only metadata/title change — and reads must still hydrate the full Document.
+    """
+    dim = Config.embeddings.model.vector_dim
+    config = Config.model_copy(deep=True)
+    config.storage.auto_vacuum = False
+
+    async with HaikuRAG(temp_db_path, config=config, create=True) as client:
+        created = await client.import_document(
+            _docling_doc("doc", "Body text"),
+            [Chunk(content="Body text", embedding=[0.1] * dim, order=0)],
+            uri="mem://meta-bloat",
+            title="Original",
+            metadata={"source_revision": "rev-0"},
+        )
+        assert created.id is not None
+
+        docs_v0 = await client.store.documents_table.version()
+        meta_v0 = await client.store.document_meta_table.version()
+
+        for i in range(1, 6):
+            await client.update_document(
+                created.id,
+                metadata={"source_revision": f"rev-{i}"},
+                title=f"Title {i}",
+            )
+
+        # The heavy documents table must not advance on metadata-only updates.
+        assert await client.store.documents_table.version() == docs_v0
+        # The light document_meta table absorbs the updates.
+        assert await client.store.document_meta_table.version() > meta_v0
+
+        # Reads still hydrate the full document (content + blobs + metadata).
+        fetched = await client.get_document_by_id(created.id)
+        assert fetched is not None
+        assert fetched.metadata["source_revision"] == "rev-5"
+        assert fetched.title == "Title 5"
+        assert fetched.content == "Body text"
+        assert fetched.get_docling_document() is not None
+
+
 @pytest.mark.vcr()
 async def test_client_ask(allow_model_requests, temp_db_path):
     """Test asking questions returns answer and citations (VCR recorded)."""

tests/test_lancedb_connection.py

@@ -267,7 +267,7 @@ class TestInitFailureCleanup:
         async def fake_connect(*args, **kwargs):
             return mock_conn
 
-        async def failing_init_tables(self):
+        async def failing_init_tables(self, is_new_db):
             raise RuntimeError("simulated table init failure")
 
         monkeypatch.setattr("haiku.rag.store.engine.connect_lancedb", fake_connect)

tests/test_rebuild.py

@@ -6,6 +6,7 @@ from typing import TypedDict
 import pytest
 
 from haiku.rag.client import HaikuRAG, RebuildMode
+from haiku.rag.config import Config
 
 
 class ChunkData(TypedDict):
@@ -184,7 +185,14 @@ async def test_rebuild_resumes_phase2_from_staging_after_crash(
         _StagingMarkerRecord,
     )
 
-    async with HaikuRAG(temp_db_path, create=True) as client:
+    # auto_vacuum off: this test drops the chunks table by hand to simulate a
+    # crash, where no background vacuum would be in flight. Leaving it on lets
+    # create_document's scheduled optimize race the raw drop_table ("Directory
+    # not empty").
+    config = Config.model_copy(deep=True)
+    config.storage.auto_vacuum = False
+
+    async with HaikuRAG(temp_db_path, config=config, create=True) as client:
         doc = await client.create_document(content=qa_corpus[0]["document_extracted"])
         assert doc.id is not None
         original_chunks = await client.chunk_repository.get_by_document_id(doc.id)