Oracle Exadata Review
The presence of storage indexes along with the Storage Server software, allows us to deliver better performance without indexes.


Valuable Features

The most valuable feature is the integration of the various components that make the performance soar. More specifically the presence of storage indexes along with the Exadata Storage Server software, which delivers process offloading, allows us to deliver better performance without indexes--saving space and CPU. This innovative feature is not something we would be able to replicate with other solutions. In addition, we consider the features smart scan, smart flashcache, smart flash log and hybrid columnar compression very useful.

Improvements to My Organization

Prior to Exadata, we were relying on daily ETLs from multiple source systems to load data into base tables, then we prepared a summary and materialized views from the base to data marts which were eventually exposed to the end users. This process used to take 18 hours. So, the data was always at least 18 hours late, and occasionally later, if the ETLs failed. This caused two issues: first, most managers simply were not able to make quick decisions because the data was stale and second, for most important functions, the users got the data from our OLTP system which taxed that system's capacity.

After Exadata, we observed three immediate benefits:

  • The ETLs finish in 3 hours (down from 18), making the data fresh and enabling the managers to make quick decisions. Campaigns used to take days but take a few hours now
  • Users no longer go to the OLTP system, reducing the impact there and saving us from upgrades
  • There is no need to build summaries; so some of the data is available almost immediately, allowing most decisions to be taken on near-realtime data which was impossible pre-Exadata

Room for Improvement

There are three possible enhancements:

  • Build a stronger, more responsive support team.
  • Add a RAID-5 like storage layout for customers to save space with the full understanding that performance will be less (which could be fine for non-prod systems).
  • Add storage level replication without the use of Data Guard, which is quite useful in case of organizations that rely on that technology for their Disaster Recovery effort.

Use of Solution

I've used it for 4 years

Deployment Issues

Yes; mostly due to the database version being different. We were upgrading from 10g to Exadata which ran 11g; so there were some issues we had to overcome; but those were expected. Quite honestly, our deployment was smooth in Exadata itself due to our deep understanding of the technology. Without it, I am not sure if it would have been that smooth.

Stability Issues

Yes; the initial versions had a lot of firmware issues that caused the cells to reboot, which caused the ASM software to rebalance the diskgroups. It mostly occurred in the X2 system. The X4 system has been quite stable. However, it's important to point out that Oracle generally releases firmware updates quite fast to remove any stability issues. We encountered them because we didn't apply these due to our internal reasons.

Scalability Issues

No; scalability has been pretty awesome.

Customer Service and Technical Support

Customer Service:

It leaves a lot to be desired. It has improved; but still a lot to go. I rate it 6 on a 10 point scale.

Technical Support:

I gave an overall rating of 9 to Exadata X4 due to the quality of support personnel during installation and after sales events. That is going up but still leaves something to be desired.

Previous Solutions

We used Oracle database on HPUX. We switched because it was impossible to deliver performance without additional indexes. Indexes took up space and slowed down data insertion performance. Exadata solved these by enhancing performance without the need for indexes.

Initial Setup

Oracle sends professional installers for installation and deployment. So it was fairly simple. However, as I mentioned earlier, we do have a deep technical expertise base so it worked in our favor. Without that expertise, I can't be sure if would not have been complex.

Implementation Team

We implemented everything with our in house team.

Other Solutions Considered

Yes, we did evaluate Teradata, Netezza and Greenplum.

Other Advice

First and foremost, develop or hire a deep technical talent base inhouse, even if it's just one person. The technical role is called Database Machine Administrator (DMA). Planning is winning half the battle. There are tiny little things that makes a big difference. For instance, how to decide whether to keep the indexes you have--it's not something you can outsource. Second, get the installation checklist (detailed) from Oracle and establish SLAs for each item meticulously along with the hand off details. Third, if you don't have it, consider Oracle Enterprise Manager Grid Control to manage the Exadata system. Fourth, decide to use Oracle Platinum Support (free for Exadata) from day one. Finally, get ready to be wowed.

The innovative use of all the technologies integrated so creatively and functionally that it provides an immense performance boost impossible to attain with do it yourself systems. For instance the secret sauce is Exadata Storage Server (ESS) software, which is unique to Exadata, can't be replicated even with other massively parallel systems.

Disclosure: IT Central Station contacted the reviewer to collect the review and to validate authenticity. The reviewer was referred by the vendor, but the review is not subject to editing or approval by the vendor.

3 Comments

Amin AdatiaConsultantTOP 20POPULAR

Don't go too wild with dropping indexes. You do need those that are for data integrity and for standard OLTP. In our first tests with Exadata X2, we did try dropping all indexes. We did not get any through put for the ETL.
Also to get any benefit from the Index Cell Storage, you do need to have parallel processing.
Sometimes, I found that the index for the partition key needed to be avoided.
Oracle Text Indexes do not follow the rules for improving standard query performance improvements.

22 May 15
Arup NandaReal UserTOP 10

Amin - thank you for the comments. Your "Don't go too wild with dropping indexes" comment applies to any advice, anywhere. Dropping indexes is not the primary objective of Exadata. And I never actually said that. What I said was that Exadata allows us to perform full table scans more effectively, which was not possible earlier. That is not the same thing as dropping existing indexes which may have been created for entirely different reasons, e.g. to enforce integrity constraints.

22 May 15
Amin AdatiaConsultantTOP 20POPULAR

Arup -- I agree don't go too wild applies to anything. However, people read these things about Exadata and go wild OR just do nothing so as to keep everything the same. And not many people talk about Oracle Text Indexes and how different the behaviour.

Also in your "travels on Exadata" have you seen any effect of gathering system statistics with the 'EXADATA' parameter?

22 May 15
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