Oracle Exadata Database Machine v2 vs x2-2 vs x2-8 Deathmatch

This post has bee updated live from the Oracle OpenWorld as I’m learning what’s new. Last update done on 28-Sep-2010. X2-2 and X2-8 configurations have evolved over time so if you are reading this post now — beware of its age. The referenced data-sheets seems to be up to date though.

Oracle Exadata v2 has been transformed into x2-2 and x2-8. x2-2 is just slightly updated while x2-8 is a much more high-end platform. Please note that Exadata x2-2 is not just an old Exadata v2 — it’s a fully refreshed model. This is a huge confusion here at the OOW and even at the Oracle web site.

The new Exadata pricing list is released and Exadata x2-2 costs exactly the same as old Exadata v2. Exadata x2-8 Full Rack (that’s the only x2-8 configuration — see below why) is priced 50% higher then Full Rack x2-2. This is hardware price only to clarify the confusion (updated 18-Oct-2010).

Exadata Storage Server Software pricing is the same and licensing costs per storage server and per full rack is the same as for Exadata v2 because number of disks didn’t change. Note that storage cells got upgraded but priced the same when it comes to Exadata Server software and hardware. Nice touch but see implications on databases licensing below.

This comparison is for Full-Rack models Exadata x2-2 and x2-8 and existing v2 model.

Finally, data-sheets are available for both x2-2 (Thx Dan Norris for the pointers):
https://www.oracle.com/technetwork/database/exadata/dbmachine-x2-2-datasheet-175280.pdf

and x2-8:
https://www.oracle.com/technetwork/database/exadata/dbmachine-x2-8-datasheet-173705.pdf

It means that live update of this post is probably over (27-Sep-2010).

x2-8 has fewer but way bigger database servers. That means that x2-8 will scale better with the less RAC overhead for the databases. The bad news is that if one database server fails or down for maintenance, 50% of capacity is gone. What does that mean? It means that Exadata x2-8 is designed more for multi-rack deployments so that you can go beyond “simple” 2 node RAC. Some folks argue that two node RAC is less reliable for evictions and etc but you probably don’t know that Exadata has special IO fencing mechanism that makes it much more reliable.

Because there is 4 times more RAM in Exadata x2-8, more and more operations can be done fully in memory without even going to storage cells. This is why boost in number of cores / CPU performance is important — since InfniBand bandwidth stays the same, you need some other way to access more data so having more data on buffer cache will keep more CPU cores busy.

With Exadata x2-2, processing capacity on database servers increased and RAM increase is insignificant. So how does it impact “well-balanced” Exadata v2? Well, if more and more operations are offloaded to storage cells then database servers could have more “useful” data pumped in over InfniBand and actually spend CPU cycles processing the data rather then filtering it. With Exadata v2, depending on the compression level, CPU was often a bottleneck on data loads so having some more CPU capacity on database tiers won’t harm.

Old configuration v2 will not be available so be ready to spend more on Oracle database licenses unless you are licensed under ULA or something.

Both Exadata x2-8 and x2-2 will run updated Oracle Linux 5.5 with Oracle Enterprise Kernel. x2-8 can also run Solaris x86 on database servers as expected. This confirms my assumption that if Oracle adds Solaris x86 into Exadata, it will prove that Oracle is fully committed to Solaris Operating System. A rather pleasant news to me! However, Solaris 11 Express is not available right now and probably will be available towards the end of this calendar year.

If you look at x2-2 and x2-8 side by side physically, you will see that four 1U databases servers of x2-2 basically replaced by one 5U database server in x2-8 in terms of space capacity. There are also more internal disks in those bigger servers and more power supplies so they are more redundant.

More processing power on storage servers in x2-8 and x2-2 (not dramatically more but definitely noticeable) will speed up smart scans accessing data compressed with high level. As more and more operations can be uploaded to the storage cells, boost in CPU capacity there is quite handy. Note that this doesn’t impact licensing in any way — Exadata Storage Server Software is using number of physical disk spindles as the licensing metric.

Regarding claims of the full database encryption — need to understand how it works and what are the improvements. Oracle Transparent Data Encryption was available on Exadata v2 but had many limitations when using with other Exadata features. I assume that Exadata x2-x addresses those but need to follow up on details so stay tuned. I believe that customers of Exadata v2 will be able to take advantage of all new Exadata software features – the platform architecture hasn’t changed.