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Question 275 - DBS-C01 discussion

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A database specialist is designing the database for a software-as-a-service (SaaS) version of an employee information application. In the current architecture, the change history of employee records is stored in a single table in an Amazon RDS for Oracle database. Triggers on the employee table populate the history table with historical records.

This architecture has two major challenges. First, there is no way to guarantee that the records have not been changed in the history table. Second, queries on the history table are slow because of the large size of the table and the need to run the queries against a large subset of data in the table.

The database specialist must design a solution that prevents modification of the historical records. The solution also must maximize the speed of the queries.

Which solution will meet these requirements?

A.
Migrate the current solution to an Amazon DynamoDB table. Use DynamoDB Streams to keep track of changes. Use DynamoDB Accelerator (DAX) to improve query performance.
Answers
A.
Migrate the current solution to an Amazon DynamoDB table. Use DynamoDB Streams to keep track of changes. Use DynamoDB Accelerator (DAX) to improve query performance.
B.
Write employee record history to Amazon Quantum Ledger Database (Amazon QLDB) for historical records and to an Amazon OpenSearch Service domain for queries.
Answers
B.
Write employee record history to Amazon Quantum Ledger Database (Amazon QLDB) for historical records and to an Amazon OpenSearch Service domain for queries.
C.
Use Amazon Aurora PostgreSQL to store employee record history in a single table. Use Aurora Auto Scaling to provision more capacity.
Answers
C.
Use Amazon Aurora PostgreSQL to store employee record history in a single table. Use Aurora Auto Scaling to provision more capacity.
D.
Build a solution that uses an Amazon Redshift cluster for historical records. Query the Redshift cluster directly as needed.
Answers
D.
Build a solution that uses an Amazon Redshift cluster for historical records. Query the Redshift cluster directly as needed.
Suggested answer: B

Explanation:

Answer:: BExplanation from Amazon documents:Amazon Quantum Ledger Database (Amazon QLDB) is a fully managed ledger database that provides a transparent, immutable, and cryptographically verifiable transaction log of all your application changes. Amazon QLDB tracks each and every application data change and maintains a complete and verifiable history of changes over time1. This makes it ideal for storing historical records that need to be tamper-proof and auditable. Amazon QLDB also supports PartiQL, a SQL-compatible query language that lets you query data using familiar SQL operators2.Amazon OpenSearch Service (successor to Amazon Elasticsearch Service) is a fully managed service that makes it easy to deploy, operate, and scale OpenSearch, an open source search and analytics engine. Amazon OpenSearch Service lets you store, search, and analyze large volumes of data quickly and at low cost3. You can use Amazon OpenSearch Service to index and query your employee record history data stored in Amazon QLDB using the QLDB Streams feature. This way, you can leverage the powerful search and analytics capabilities of OpenSearch Service to run fast and flexible queries on your historical data.Therefore, option B is the best solution that meets the requirements of preventing modification of the historical records and maximizing the speed of the queries. Option A is not suitable because DynamoDB is a key-value and document database that does not provide a ledger-like transaction log. Option C is not suitable because Aurora PostgreSQL is a relational database that does not guarantee immutability of the historical records. Option D is not suitable because Redshift is a data warehouse that is optimized for analytical queries on large datasets, not for storing and querying individual records.

asked 16/09/2024
Katherine Messick
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