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 Guide (to evaluate which parameters 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 or Fleet Patching and Provisioning Zero application downtime with Application Continuity: MAA Checklist for Preparation Seconds to minutes database downtime with Standby-First Patch Apply and subsequent Data Guard Switchover |
|
Oracle interim or diagnostic software updates or patches |
Zero downtime with Online Patching Zero database downtime with Oracle RAC and Oracle RAC One Node. Zero application downtime with Application Continuity: MAA Checklist for Preparation |
|
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 Continuity: MAA Checklist for Preparation 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 GoldeGate 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 storage or Exadata switch software updates |
Zero downtime using Exadata
|
|
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 Continuity: MAA Checklist for Preparation 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 |
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 Exadata Database Machine systems in the cloud or on-premises |
See Oracle Zero Downtime Migration at https://www.oracle.com/database/technologies/rac/zdm.html for solutions with near zero downtime. |
|
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 |
|
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 |