You manage an Azure Cosmos DB SQL API container that stores event documents. By default, events must be deleted after 7 days. Certain audit events must be kept for 90 days, and a small set of documents must never expire. What should you configure to meet all requirements with minimal code?

Azure Cosmos DB's Time-to-Live (TTL) feature is designed for automatic document expiration. Enabling TTL on the container and setting a default of 604800 seconds (7 days) ensures most documents expire as required. For audit documents needing a longer retention, a per-item ttl property can override the container's default, setting it to 7776000 seconds (90 days). Documents that should never expire can also override the default by setting their per-item ttl property to -1. This approach uses built-in Cosmos DB functionality, minimizing custom code. Disabling TTL and using the change feed would require custom logic for deletion, which is more complex. The indexing policy is unrelated to document expiration.