What is our primary use case?
Most recent involvement was the migration of a large database from a non-relational legacy database requiring redundancy with aggressive recovery time objectives (RTO) and recovery point objectives (RPO) for the disaster recovery (DR) environment. We also had a requirement to have the migration completed and the data validated within a single long weekend.
Significant assistance in tuning both the migration process and the production database was provided by Oracle Consulting Services, which provided excellent and very professional advice.
How has it helped my organization?
Switching to Oracle significantly increased stability of the application, and enabled ongoing growth of the application's data. It also provided better insight and diagnostics when data problems were encountered by the application.
What is most valuable?
RAC clustering allowed us to improve performance and provided additional redundancy. In general, the enterprise-grade features of Oracle are second to none.
What needs improvement?
In the case noted above, the converted legacy data was stored as XML. The 11gR2 version we converted to stored it as a Character Large OBject (CLOB). The next version of Oracle has a native XML data type, which provides better support for indexing the XML data.
For how long have I used the solution?
More than five years.
What do I think about the scalability of the solution?
Because of the way the application used the database, we found that two data servers increased performance, but a third one decreased it. This was a limitation based on the way the legacy application configured and used their data and how they did their own locking, which made their lock table a hotspot for the clustering, among other issues.
How are customer service and technical support?
There was a bit of a learning experience on how to escalate an issue, but once we got through that, the vendor support was really very good.
Which solution did I use previously and why did I switch?
The previous solution was a non-relational multi-valued database called jBASE. The database size was exceeding the application vendor's recommended maximum for that database, but their application had the ability to use a number of relational databases with their enterprise features as an alternate data store allowing continued growth.
How was the initial setup?
Initial setup was complex because of the odd way the application used the database, the application vendor's conversion tools, and our stringent requirements.
What about the implementation team?
Implementation was done by a combination of the vendor, the application vendor, and in-house. The vendor teams were exceptionally good.
What was our ROI?
The ability to continue growing and increased stability were our non-negotiable points.
What's my experience with pricing, setup cost, and licensing?
Be prepared to pay for consulting services, and do not underestimate the time required to find and hire good quality database administrators. Also, carefully evaluate your sizing and performance requirements, involving if you can, both the application vendor and Oracle consultants.
Which other solutions did I evaluate?
In addition to Oracle, we evaluated SQL Server and DB2.
What other advice do I have?
Do a couple dry runs do thorough testing to ensure that everything will work as expected.