Unofficial Oracle Database Appliance FAQ
Sep 21, 2011 / By Marc Fielding
I’ve started putting together some information about the Oracle Database Appliance in question-and-answer form. If you have an unanswered question, ask away in the comment section below.
(Update: Oracle has come out with their official FAQ as well)
ODA offers the benefits of engineered, pre-configured systems for environments too small for Exadata. These benefits include fast deployment, simple configuration, and a tested and certified combination of hardware and software.
What database versions can I use with ODA?
At this point, only Oracle 188.8.131.52 enterprise edition. I’d expect future Oracle versions to run on the ODA as well.
How is the software licensed?
The Oracle database appliance is licensed on a per-processor basis at the same rate as for other platforms. Existing Oracle per-processor licenses can be used with ODA. It’s possible to license a subset of processors, but after the initial sizing, the processor count cannot be decreased, only increased.
What kind of HA (high availability) options exist with ODA?
The ODA hardware is completely redundant internally. ODA can participate in the same HA configurations as other Oracle database servers, including Oracle Data Guard and Oracle GoldenGate.
How is the flash memory used?
ODA comes configured with flash storage in a REDO diskgroup, holding database redo logs
Why should I store redo logs in flash memory
Traditional enterprise storage infrastructure uses battery-backed memory caches to buffer writes, significantly improving commit latency for Oracle databases. Since ODA doesn’t have such a cache, it uses flash memory for this purpose instead. (As of version 184.108.40.206.0, Exadata does this too)
Can the flash memory be used as a read cache?
No; the flash storage is optimized for redo caching only. It uses a different ASM block size through an ODA-specific version of ASM.
Can I hook the ODA up to my SAN?
ODA does not have a fiber HBA card so can’t connect directly to fiber channel fabrics. However, ODA can access SAN disks via IP protocols like iSCSI or NFS, though they have higher overhead than ODA’s own direct-attached disk.
Can I connect multiple ODA units together?
Each ODA device is self-contained, and communicates externally with comparatively slow network access, so you would typically want to separate databases between ODA units. If you’re looking at a larger configuration, consider Exadata instead
Can I store regular files on the ODA’s shared storage?
Yes. Since it has direct-attached disk, ODA can use Oracle’s ASM cluster filesystem (ACFS) filesystems to store regular OS files in ASM, accessible to both system controllers in the ODA.
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