Blob-created events from Azure Storage should start RAG indexing without polling. Which Event Grid topic type is the natural fit?
Select an answer to reveal the explanation.
Short Explanation
When Azure Storage creates a blob, you can subscribe to its system topic and start RAG indexing without polling. That’s simpler than asking staff to publish an event for every upload.
Full Explanation
When Azure Blob Storage creates objects that should start municipal RAG indexing without polling, subscribe to the Azure Storage system topic (or matching resource events) in Event Grid. Events such as Microsoft.Storage.BlobCreated arrive automatically; a subscription can filter for the ordinance or knowledge container and invoke the indexer Function, avoiding timer-based scans of the account. A partner topic is for third-party SaaS integrations, not Azure Storage system events. A Service Bus topic is a messaging entity and does not natively emit Blob Storage change notifications by pretending to be storage. A custom topic requires staff to publish each blob event manually, adding human delay and defeating event-driven indexing. Exam caveat: distinguish system topics for Azure resources, custom topics for application events, and partner topics for SaaS; for “blob created → start RAG,” the storage system topic is the natural fit, with filters to scope which containers trigger indexing. Practical check: enable the storage account system topic, create a subscription with subject or container filters targeting the RAG indexer Function, upload a test ordinance PDF, and verify that a BlobCreated event arrives, the Function runs once, and the index updates without a polling schedule.