The preview for long-term backup retention in Azure SQL Database was announced in October 2016, providing you with a way to easily manage long-term retention for your databases – up to 10 years – with backups stored in your own Azure Backup Service Vault.
Based upon feedback gathered during the preview, we are happy to announce a set of major enhancements to the long-term backup retention solution. With this update we have eliminated the need for you to deploy and manage a separate Backup Service Vault. Instead, SQL Database will utilize Azure Blob Storage under the covers to store and manage your long-term backups. This new design will enable flexibility for your backup strategy, and overall more control over costs.
Read about it in the Azure blog.