5 Oracle Database High Availability Solutions for Planned Downtime

Planned downtime can be just as disruptive to operations as unplanned downtime. This is especially true for global enterprises that must support users in multiple time zones, or for those that must provide Internet access to customers 24 hours a day, 7 days a week.

See the following topics to learn about keeping your database highly available during planned downtime.

Oracle High Availability Solutions for Planned Maintenance

Oracle provides high availability solutions for all planned maintenance.

The following table describes the various Oracle high availability solutions and their projected downtime for various maintenance activities.

Table 5-1 Oracle High Availability Solutions for Planned Maintenance

Maintenance Event High Availability Solutions with Target Outage Time

Dynamic and Online Resource Provisioning, or

Online reorganization and redefinition

Zero application and database downtime for

See the Oracle Database Administrator Guide, Oracle Database Reference (to evaluate which parameters to use on dynamic), and Online Data Reorganization and Redefinition

Operating system software or hardware updates and patches

Zero database downtime with Oracle RAC and Oracle RAC One Node Rolling

Seconds to minutes database downtime with Standby-First Patch Apply and subsequent Data Guard Switchover

Oracle Database or Grid Infrastructure interim or diagnostic patches

Zero downtime with Database Online Patching or Zero-Downtime Oracle Grid Infrastructure Patching

Zero database downtime with Oracle RAC and Oracle RAC One Node Rolling

Zero application downtime with Application Checklist for Continuous Service for MAA Solutions

Seconds to minutes database downtime with Standby-First Patch Apply and subsequent Data Guard Switchover

Oracle Database or Grid Infrastructure quarterly updates under the Critical Patch Update (CPU) program, or Oracle Grid Infrastructure release upgrades

Zero database downtime with Oracle RAC and Oracle RAC One Node Rolling.

Zero application downtime with Application Checklist for Continuous Service for MAA Solutions

Seconds to minutes downtime with Standby-First Patch Apply and subsequent Data Guard Switchover

Oracle Database Release Upgrade (for example, Oracle Database 11g to 12.2 or 12.2 to 19c)

Seconds to minutes downtime with Data Guard transient logical or DBMS_ROLLING solution

Zero downtime with Oracle GoldenGate

See Automated Database Upgrades using Oracle Active Data Guard and DBMS_ROLLING for 12.2 and higher database releases or Database Rolling Upgrade using Data Guard for older releases.

Exadata database server software updates

Zero database downtime with Oracle RAC Rolling

Zero application downtime with Application Checklist for Continuous Service for MAA Solutions

Seconds to minutes downtime with Standby-First Patch Apply and subsequent Data Guard Switchover

See Updating Exadata Software

Exadata storage server or Exadata switch software updates

Zero downtime using Exadata patchmgr

See Updating Exadata Software

Database Server or Oracle RAC cluster changes (add node, drop node, adjust CPU or memory size of the database server)

Some hardware changes like adjusting CPU can be done online without restarting the database server. Refer to the hardware specific documentation.

If the change is not online, then

Zero database downtime with Oracle RAC and Oracle RAC One Node Rolling.

Zero application downtime with Application Checklist for Continuous Service for MAA Solutions

Seconds to minutes downtime with Standby-First Patch Apply and subsequent Data Guard Switchover

Application upgrades

Zero downtime with Edition Based Redefinition

Zero downtime with Oracle GoldenGate

See Edition Based Redefinition and Oracle GoldenGate documentation

Fleet-wide software maintenance events

  • Oracle Database or Grid Infrastructure interim or diagnostic patches
  • Oracle Database or Grid Infrastructure quarterly updates under the Critical Patch Update (CPU) program, or Oracle Grid Infrastructure release upgrades
  • Exadata database server software updates
  • Exadata storage server or Exadata switch software updates

Use Fleet Patching and Provisioning, which leverages the following high availability solutions to achieve the target outage times for fleet-wide software maintenance events:

Zero database downtime with Oracle RAC and Oracle RAC One Node Rolling

Zero application downtime with Application Checklist for Continuous Service for MAA Solutions for

  • Oracle Database or Grid Infrastructure interim or diagnostic patches
  • Oracle Database or Grid Infrastructure quarterly updates under the Critical Patch Update (CPU) program, or Oracle Grid Infrastructure release upgrades
  • Exadata database server software updates

Zero downtime using Exadata patchmgr for Exadata storage server or Exadata switch software updates

High Availability Solutions for Migration

Oracle MAA recommends several solutions for reducing downtime due to database migration.

The following table describes the high availability solutions for migration at a high level.

Table 5-2 High Availability Solutions for Migration

Maintenance Event High Availability Solutions with Target Outage Time

Migrate to Oracle Cloud or any on-premises or cloud Oracle Exadata Database Machine system

(Oracle Cloud includes Exadata Cloud Service (ExaCS), Exadata Cloud@Customer (ExaCC) ,Autonomous Database (ADB) or Database Cloud Service (DBCS)

To migrate to an Oracle Exadata Database Machine on-premises or any Oracle Cloud service, use the Zero Downtime Migration tool, which provides

  • Physical migration with RMAN backup and restore, with an optional low downtime option using Oracle Data Guard. This is the simplest turnkey migration solution, which is ideal when the source and target system platform (for example, Linux to Linux) and database versions (Oracle Database 19c to 19c) are the same.

  • Logical migration with Oracle Data Pump, with an optional low downtime option using Oracle GoldenGate. This is the only option for migrating a database when the source and target system platform (For example, AIX to Linux) or major database versions (Oracle Database 12c to 19c) are different.

To migrate to Oracle Autonomous Database, use the Oracle Cloud Infrastructure Database Migration service (or the Zero Downtime Migration tool), which provide

  • Offline migration with Data Pump
  • Online migration with Data Pump and Oracle GoldenGate

Migrate the database to a different server or platform

Seconds to minutes downtime with Oracle Data Guard for certain platform combinations

Zero downtime with Oracle GoldenGate

Data Guard always supports primary and standby combinations on the same platform. For heterogeneous platforms, Refer to Data Guard Support for Heterogeneous Primary and Physical Standbys in Same Data Guard Configuration (Doc ID 413484.1)

Migrate database to an incompatible character set

Zero downtime with Oracle GoldenGate

See Character Set Migration

Migrate to pluggable databases to another container database

Seconds to minutes downtime with Pluggable Database Relocate (PDB Relocate)

See Relocating a PDB

Migrate to new storage

Zero Downtime with Oracle Automatic Storage Management if storage is compatible

with Oracle Data Guard for certain platform combinations

Zero Downtime with Oracle GoldenGate

Migrate database from a single-instance system to an Oracle RAC cluster

Zero Downtime with Oracle RAC when applicable. See Adding Oracle RAC to Nodes with Oracle Clusterware Installed

Seconds to minutes downtime with Oracle Data Guard for certain platform combinations

Zero Downtime with Oracle GoldenGate