DynamoDB

  • DynamoDB is fast and flexible NoSQL DB. It can be used for all application that needs consistent, single-digit millisecond latency at any scale. It is fully managed database.  And supports both document and key-value data model.
  • Stored in SSD storage.
  • Spread across three geographically distinct data centers.
  • Eventual Consistent Read (Default).
    • Consistency across all copies of the data is usually reached within 1 second. Repeating a read after a short time should return an updated data.
  • Strongly consistent Read.
    • Returns a result that reflects all writes that received successful response prior the read.
  • DynamoDB pricing
    • Provisioned Throughput capacity.
      • Write Throughput $0.0065 per hour for every 10 units.
      • Read Throughput $0.0065 per hour for every 50 units.
    • Storage cost of $0.25GB per month.


Database Overview

  • AWS database types
    • RDS – OLTP        
      • SQL
      • MySQL
      • PostgreSQL
      • Oracle
      • Aurora
      • MariaDB
    • No SQL Database
      • DynamoDB
    • RedShift – OLAP
    • Elastic Cache – In Memory Cache
      • MemCached
      • Redis
  • Encryption of the Database
    • Encryption at REST is supported for MySQL, Oracle, SQL, PostgreSQL, MariaDB and Aurora.
    • Encryption is done by AWS KMS service (Key Management Service).
    • Once the RDS instance is encrypted. The data stored at REST in the underlying storage is encrypted.
    • This is applicable for Automated, Read Replicas and Snapshots.
    • At present, Encryption of the existing database is not supported. To use Amazon RDS encryption for the existing database, you must first create a snapshot, make a copy of that snapshot and encrypt the copy.