This blog will take a brief look at Oracle RDS vs Oracle RDS Custom.
Oracle RDS Oracle should be considered as first choice by most RDS Oracle users due to its administration and automation. It’s a proven managed solution.
The Oracle RDS Regular managed database offering from AWS, provides features allow provisioning and managing a Database without the normal of level of database administrator skills normally required. Oracle RDS Regular has been available from AWS for many years so is a tried and tested model for many organisations. There is still a need for DBA/Developer guidance for Performance, which is not covered by RDS as ‘Application Optimisation’ is always the customer’s responsibility.
Key Features:
- Supports multiple Oracle editions (e.g., Standard Edition, Enterprise Edition) under oth Bring Your Own License (BYOL) or License Included models for Standard Edition
- Automates provisioning, patching, backup and recovery
- Provides auto scaling functionality
- Enable Multi-AZ ‘disk’ replication for high availability
- Read replicas for improved read performance with Active Dataguard License on Enterprise Edition
- Wide choice of Instance types for various workloads such as memory OR compute intensive
- Backups Automation
- Performance Monitoring using Performance Insights
AWS manages:
- Operating System
- Database software binaries
- EC2 Infrastructure
Uses Cases:
- Standard Oracle workloads
- Use of Standard Database features with default or best practice setup
Limitations:
- No access to the underlying OS hosting the database
- No SYS user access
- No direct access or control over the Oracle binaries
Oracle RDS Custom offers greater customisation at the cost of automation and administration. It is a magnitude more complicated to setup and support and needs a Database Administrator. Oracle RDS Custom allows organisations to access host databases O/S where the Oracle RDS database is running. Being able to access the Database host opens up the flexibility to tailoring Oracle RDS as needed. It also removes some desirable limitations from the RDS Regular offering such as:
- Database software version custom patching
- Setting up Oracle Dataguard in maximum availability mode
- Use of Oracle Flashback Database
- Customisations needed by 3rd party Applications
Key Features:
- End user access to host where Database is running
- Access to sys account on the Oracle database
- Supports both Standard Edition and Enterprise Edition
- Install one off patches
- Support Dataguard replicas in both ASYNC and SYNC modes of operation
AWS manages:
- hardware Infrastructure
- Users are responsible for database and OS customizations, patching
Use Cases:
- Legacy or packaged applications that need specific Oracle configurations or OS access.
- Workloads needing features unsupported by standard RDS
Limitations:
- No support for License Included
- No Multi-AZ deployment ‘Disk’ replication
- No stopping of instance to reduce costs
- only basic automation provided by AWS tooling
Comparing RDS Regular to RDS Custom at a high level
If we think about database manually hosted on EC2 outside of RDS as one extreme, RDS Oracle as the other extreme, RDS Oracle Custom sits somewhere in between.
Summary
Oracle RDS Custom is an AWS offering of Oracle RDS that provides access to the database host to facilitate lower level customisations and capabilities. This includes one off patching, Dataguard in SYNC mode and use of Oracle Flashback.