Microsoft Certified: Azure Solutions Architect ExpertDesign data storage solutionsHard

A financial institution needs to store customer transaction records for regulatory compliance. These records must be immutable for 7 years and cannot be deleted or modified during this period, even by administrators. After 7 years, the records can be deleted. The data volume is expected to reach petabytes. Which Azure storage solution and configuration best meets these requirements?

  1. AAzure Blob Storage with a time-based retention policy on a WORM (Write Once, Read Many) immutable vault.
  2. BAzure Archive Storage with soft delete enabled and a long retention period.
  3. CAzure SQL Database with 'ALTER DATABASE SET SINGLE_USER' to prevent modifications.
  4. DAzure Data Lake Storage Gen2 with POSIX ACLs and a custom retention script.
Show answer & explanation

Correct answer: A. Azure Blob Storage with a time-based retention policy on a WORM (Write Once, Read Many) immutable vault.

Azure Blob Storage supports immutability policies, including time-based retention policies that prevent deletion or modification of data for a specified duration, even by users with administrative privileges. This meets the WORM requirement for regulatory compliance and can scale to petabytes.

Why the other options are wrong

  • B. Azure Archive Storage is a tier of Blob Storage, but 'soft delete' only protects against accidental deletion, not against intentional deletion or modification by privileged users for regulatory compliance.
  • C. Azure SQL Database does not natively support WORM immutability that prevents administrator actions, and 'SINGLE_USER' mode is for maintenance, not compliance.
  • D. Azure Data Lake Storage Gen2 with POSIX ACLs controls access but does not enforce WORM immutability that prevents modification or deletion by administrators for a fixed period.

Azure Blob Storage Immutability Policies

A feature of Azure Blob Storage that allows objects to be stored in a Write Once, Read Many (WORM) state, preventing modification or deletion for a specified period or indefinitely.

  • Supports time-based retention and legal hold policies.
  • Ensures data integrity for regulatory compliance.
  • Protects data even from accounts with administrative privileges once locked.

Memory trick: Immutable blobs lock down history, even from admins.

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