(1) So all these hardware is used to run only one DB (which indeed may be requiring high end configuration
A quarter rack gives you two database servers. You can run a single database, or more than one, at your choice. The main factor governing the maximum umber of databases is typically the amount of memory in the servers, so I wouldn't suggest running thousands of databases on a single server.
(2) whats the actual meaning of 2 DB servers ? you can use it for setting up two node RAC system [Assuming 1 DB server for one node] ?
You get two physical servers that run Oracle database software. You can indeed set up a two node RAC system, and this is the most common configuration.
(3) can these DB servers can be accessed individually to run heterogeneous environment of Databases like using 1 DB server for 1 database ..
Absolutely. Or just run multiple databases on your two-node RAC system.
The Oracle RAC documentation has more information about the differences between databases, clusters, instances, and servers.
Thanks for your reply. Can you please answer me one more doubt please.
Assuming there are two dB servers in a quarter rack can we install Oracle VM on top of each dB server and then run multiple databases on top of it.(like we do in a virtualize environment) ?
I heard that exadata is very much closed system. So does this kind of customization possible in exadata machine?
No Oracle Vm is not supported on Exadata .
Yo can of course run multiple instanes on the same db nodes which is generally what people do. Virtualization especially becuase of io overheads is not good for extreme performance, and hence Oracle has stayed away from it in this case.So if you want perfromance avaoid OS level virtualization
With the new PDB/CDB concept coming up the better choice is to virtualize your database and not your operating system.
Exadata x4-2 with Cell Software 18.104.22.168.0 will support Oracle Database 12c and Oracle Database 11g R2. You can create multiple Oracle RAC Databases (11g R2) / Multiple Pluggable Databases (12c).
Exadata will comes with RAC by default. ASM is Storage Volume Management. RMAN is default database backup tool. All three are mandatory skills and mandatory technologies for Oracle Exadata.
Example : We have created 4 RAC Database Instances in Exadata Half Rack Configuration (x2-2). Past one year it is working without any outages and without any performance bottlenecks.
Hi again user12054962,
Rather than virtualizing (and having the overhead of maintaining several copies of the operating system), I'd suggest simply running multiple databases on a single database server.
What types of customization do you have in mind for your database servers?