Comparing Oracle Database Appliance and Exadata

Posted in: Technical Track

Oracle Database Appliance (ODA) is in many ways similar to an Exadata quarter rack: they both use two similar compute servers in an engineered system configuration, with shared storage and flash storage. But in other ways, especially networking and storage, they differ significantly. In particular:

  • Storage connectivity: ODA uses SAS direct attachment, while Exadata uses an InfiniBand backbone connected to dedicated storage servers
  • Flash memory: Exadata has significantly more flash memory than ODA does. While both can store ASM diskgroups in flash, Exadata also has flash cache capability. ODA’s default configuration uses flash to store redo logs; this helps compensate for ODA’s lack of
    battery-backed disk write cache in the latency-sensitive redo write workload.
  • Expandability: ODA currently comes in a single 2-server, 12TB configuration. An Exadata quarter-rack configuration has
    2 compute servers and a minimum of 21TB raw storage. Both compute capacity and storage are expandable virtually without limit, given sufficient number of racks and network backbone.

The chart below summarizes the similarities and differences:

ODAExadata X2-2
Number of compute servers22
Server typeX4370 M2X4170 M2
Compute node expansionNoneExadata half rack
OSOEL 5.5OEL 5.5
Flash size292G1152G
Flash typeMLCSLC
Flash usageASM diskgroupFlash cache or ASM diskgroup
Database version11gR211gR2
Cluster interconnect2xGigE using Oracle Redundant InterconnectInfiniBand, active-passive
Raw speed2gbps40gbps
External connectivity (per server)2x10GigE, 4xGigE2x10GigE, 4xGigE
Drive type600G SAS600G or 2TB SAS
Number of drives2036
Raw shared disk capacity12TB21.6TB (high speed) or 72TB (high capacity)
Storage expansionNoneExadata half rack or additional storage servers
Local storage2x500G SATA4x300G SAS
RAM96 GB/server96 GB/server
CPU2xX5675 3.06Ghz/server2xX5675 3.06Ghz/server
Storage accessSASOracle IDB over InfiniBand
Battery-backed write cacheNone512m/storage server

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About the Author

Marc is a passionate and creative problem solver, drawing on deep understanding of the full enterprise application stack to identify the root cause of problems and to deploy sustainable solutions. Marc has a strong background in performance tuning and high availability, developing many of the tools and processes used to monitor and manage critical production databases at Pythian. He is proud to be the very first DataStax Platinum Certified Administrator for Apache Cassandra.

5 Comments. Leave new

Exadata X2-2 has 3,06 Ghz Cpu for some weeks, look at the updatet spec sheets. That was a silent update :)


Keeping up with the Joneses I guess. Good catch and specs are updated.

Pythian & Oracle Database Appliance in the news | The Pythian Blog
September 23, 2011 7:26 pm

[…] Comparing Oracle Database Appliance and Exadata […]

Roger Eisentrager
November 1, 2011 12:10 pm

Does anyone know if ODA will require ZFS on the filesystem ? I have been researching this for awhile, and can locate the answer to this question. I would appreciate if anyone could answer this. Thanks.


ODA does not use ZFS. So not only it doesn’t require ZFS, it does not have capabilities.

If you are looking to mount strorage from a ZFS appliance to ODA and network attached storage (NFS) then it can be done.


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