Xml and More: OCI―Knowing Database Service Basics

Video 1. OCI Level 100 - Database (Demo starts at 30:20; YouTube link)

The Oracle Cloud Infrastructure (OCI) Database service (DS) offers autonomous and user-managed Oracle Database solutions:

Fully-managed

Autonomous databases are preconfigured, fully-managed environments that are suitable for either transaction processing or for data warehouse workloads.
See OCI―Knowing Autonomous Database Basics for more information

User-managed

User-managed solutions are bare metal (BM), virtual machine (VM), and Exadata DB systems that you can customize with the resources and settings that meet your needs.

You can quickly provision a user-managed DB system or autonomous database. You have full access to the features and operations available with the database, but Oracle owns and manages the infrastructure:

In this article, we will cover mainly on Oracle provided user-managed solutions and use DS to mean either DB System or Database Service.

	Virtual Machine (VM)	Bare Metal (BM)	Exadata
Scaling	Storage (number of CPU cores on VM DB cannot be changed)	CPU (amount of available storage cannot be changed)	CPU can be scaled within a ¼, ½ and Full rack. Storage cannot be scaled
Multiple Homes/Databases	No, single DB and Home only	Yes (one edition, but different versions possible)	Yes
Storage	Block Storage	Local NVMe disks	Local spinning disks and NVMe flash cards.
Real Application Clusters (RAC)	Available (2-node)	Not Available	Available
Data Guard	Not Available	Available^*	Available^*

*: You can manually configure Data Guard on Exadata DB systems using native Oracle Database Utilities and commands. dbcli is not available on Exadata Data systems.

Figure 1. Exadata Database System with the Maximum Availability Architecture:

DS Features

OCI Database Service has the following features:

Comprehensive offerings to cover all enterprise database needs

3 Shape Types:

Exadata, Bare Metal, Virtual Machine
Each type with different shapes

Supports various Oracle database software editions, license types, database versions, and database workloads (OLTP vs DSS)

Lifecycle Automation

Provisioning, Patching, Backup & Restore

High Availability

RAC & Data Guard

Scalability

Dynamic CPU and Storage scaling

Security

Infrastructure (IAM, Security Lists, Audit logs)
Database (TDE, RMAN backup/Block volume encryption)

OCI Platform integration

Tagging, Limits and Usage Integration

License Type

License Included with OCI provisioning
Bring Your Own License (BYOL)

With Exadata DS, all types of failures are protected against, including disk, server, network and data.

Managing DS

You can use the console to perform the following tasks:

Launch DS

Which also create a database system

Start, stop or reboot DS

Billing continues in stop state for BM DB Systems because its attached local NVMe, but not for VM

Scale CPU cores (except for VM)
Scale up storage (VM only)
Terminate

When you terminate a DB system or a database, all of its resources are deleted, along with any automatic backups.
Full backups remain in Object Storage as standalone backups.

You can use a standalone backup to create a new database.

Figure 2. Db System patch (upper) vs Database patch (lower)

Patching DS

Because patching a system requires a reboot, plan to run the operations at a time when they will have minimal impact on users. To avoid system interruption, consider implementing a high availability strategy such as Oracle Data Guard.

Using the Console, API, or the database CLI (dbcli), you can perform below tasks:

Managed/On-Demand Patching

Automated applicable patch discovery and pre-flight checks/tests

On Demand Patching

N-1 patching (previous patch is available if it hasn't been applied), pre-check and patching at the click of a button

Availability during Patching

For Exadata and RAC shapes, patches are rolling.
For single node systems, Active Data Guard can be leveraged by the patch service if it is configured

2-Step Process

Patching is a 2 step process. To perform a patch operation on a

DB System
Database

Identity and Access Controls

Controls who can list patches, apply them, etc

Backup / Restore

If you plan to back up your DB system to Object Storage, you can use a service gateway with a private subnet or an internet gateway with a public subnet. To recover a database from Object Storage, you can use the Console, API, or by using RMAN.^[2]

For backup and restore, OCI Database Service supports:

Managed Backup

Exadata backup process requires creating a backup config file. See Backing Up an Exadata Database for more information.
For BM/VM backups, see "Backup Destinations" below.

Private Networking

The resources in the DS can be in a private subnet and use only private IP addresses.
Even with an internet gateway, network traffic between the DS and Object Storage does not leave the cloud and never reaches the public internet.

Backup Destinations

Object Storage (recommended) or Local Storage

For Exadata backups, read Backing Up an Exadata Database for information
For BM / VM backups, read:

Backing Up to Oracle Cloud Infrastructure Object Storage
Backing Up to Local Storage Using the Database CLI (only applicable to BM databases)

Backup Options

Automatic incremental―Runs once a day; repeats the cycle every week; retained for 30 days after you terminate the DS^[11]
Full backups―On-demand, standalone^[10]

Restore Options

To the latest
To the timestamp
To System Change Number (SCN)

Manged Backups vs. Unmanaged Backups

Managed backups

See Backing Up to Oracle Cloud Infrastructure Object

Unmanaged backups

The list of backups you see in the Console does not include any unmanaged backups (backups created directly by using RMAN or dbcli).

Automatic Backups (Incremental)

Default Policy

Not changeable at this time
Are written to Oracle owned object storage (not visible to customers)
Backup window is defined by Oracle

New backup window time will be between midnight and 6 AM in the time zone of the DS's region

To migrate yours to the new behavior, contact Oracle Support

All backups are encrypted with the same master key used for Transparent Data Encryption (TDE) wallet encryption.

Automatically retried

Oracle will get notified if the job is stuck

High Availability (HA)

Cloud Infrastructure HA

Region with 3 Availability Domain architecture

While the availability domains provide the facility for high availability, regions provide the basis for disaster recovery.

Fully redundant and non-blocking Networking Fabric

Database HA

Disk Redundancy

Normal (2-way mirroring) vs High (3-way mirroring―recommended for production)

Database RAC option
Automated Data Guard within and across ADs

Read Oracle's whitepaper on HA for more information.

Scalability

Exadata

Two kinds of scaling operations are supported for an Exadata DB system:

Scaling within an Exadata DS lets you modify compute node processing power within the system.
Scaling across Exadata DS configurations lets you move to a different configuration, for example, from a ¼ to a ½ rack.