Add parent-chunk identifier index

src/ctp_slack_bot/db/repositories/mongo_db_vectorized_chunk_repository.py

@@ -146,10 +146,16 @@ class MongoVectorizedChunkRepository(VectorRepositoryBase, VectorizedChunkReposi
             result = await self.collection.delete_many({"parent_id": parent_id})
         return result.deleted_count
 
+    async def ensure_indices_exist(self: Self) -> None:
+        await super().ensure_indices_exist()
+        index_name = "parent_chunk_unique"
+        existing_indices = await collection.index_information()
+        if index_name not in existing_indices:
+            await self.collection.create_index([("parent_id", ASCENDING), ("chunk_id", ASCENDING)], unique=True, name=index_name)
 
 class MongoVectorizedChunkRepositoryResource(AsyncResource):
     async def init(self: Self, settings: Settings, mongo_db: MongoDB) -> MongoVectorizedChunkRepository:
         vectorized_chunk_collection = await mongo_db.get_collection("vectorized_chunks")
         vectorized_chunk_repository = MongoVectorizedChunkRepository(settings=settings, collection=vectorized_chunk_collection)
-        await vectorized_chunk_repository.create_indexes()
+        await vectorized_chunk_repository.ensure_indices_exists()
         return vectorized_chunk_repository

src/ctp_slack_bot/db/repositories/vector_repository_base.py

@@ -17,9 +17,13 @@ class VectorRepositoryBase(ABC, BaseModel):
         frozen=True
         arbitrary_types_allowed = True
 
-    async def create_indexes(self: Self) -> None:
+    async def ensure_indices_exist(self: Self) -> None:
+        """Ensure that indices exist."""
+        self.ensure_search_index_exists() 
+
+    async def ensure_search_index_exists(self: Self) -> None:
         """
-        Create a vector search index.
+        Ensure that a vector search index exists.
         """
         index_name = f"{self.collection.name}_vector_index"
         try: