Database services that AWS offers

  • RDS -> Relation Database Service
  • Key/Value -> Amazon DynamoDB
  • RedShift for Data Warehouses
  • Purpose Built Solutions such as QLDB,DocumentDB

RDS

Relational Database Service is good for data when its relational. Amazon offers Aurora and you can also use other services such as Postgres,MySQL,Oracle and MariaDB. Its good for transactions that are ACID(Atomic Consistency Isolation and Durability) and features needed such as referential integrity. Its also good when data structures are static and unchanging. RDS also supports Read Replicas which means you don’t have query the live database instead you can query read replicas for the data. This helps offset load from primary DB.

Key/Value Store.(NoSQL DB)

As Amazon AWS offers DynamoDB as there key value store. These databases are redundant and consistent. It helps you process large amounts of data and consitent flow of read/write operations for various cases such as online shopping carts,online gaming where keeping the user session is important. Futhermore, It automatically spread data & traffic for tables across servers to handle throughput while maintaining consistency and fast performance. Its very good for low latency and DynamoDB supports DAX known as DynamoDB Accelaration as this supports in memory cache for items frequently requested.

RedShift

It’s used as data warehouse as it stores data in columns. It’s good for analytics and also uses AQUA (Advance Query Accelarator). AQUA -> Hardware Accelarated cache that does a substantial share of data processing in place of cache enabling RedShift 10x faster.

Purpose Built DBs

  • QLDB A fully managed ledger database. Its good for keeping track of financial changes/records.
  • Amazon DocumentDB MongoDB version, It stores JSON documents.
  • Amazon Neptune Its a fully managed graph database.
  • Amazon Keyspaces Basically Apache Cassandra. Readmore

Database Migrations.

There are two types of migrations.

  • Like to Like also known as Homogenous (MySQL to MySQL)
  • Like to Unlike also known as Hetrogenous (MySQL to Postgres)
  • In order to perform migration AWS offers DMS(Data Migration Service).
  • Like to Unlike uses SCT(Schema Conversion Tool) when migrating the database before using DMS