Oracle Exadata is a highly integrated, scale-out engineered system designed specifically for extreme database performance.
Exadata Smart Scan: Offloads SQL processing (e.g., row filtering, column projection, and AI/ML vector search) directly to the storage servers. Only the required result sets are sent to the database servers, drastically reducing network traffic and compute bottlenecks.
Public IP: The public IP address is for the server. This is the same as any server IP address, a unique address with exists in /etc/hosts.
Private IP: Oracle RAC requires “private IP” addresses to manage the CRS, the clusterware heartbeat process and the cache fusion layer.
Virtual IP: Oracle uses a Virtual IP (VIP) for database access. The VIP must be on the same subnet as the public IP address. The VIP is used for RAC failover (TAF).
Networking Files:
The "/etc/sysconfig/network" file holds top-level networking configuration, including the hostname and gateway settings.
The "/etc/sysconfig/network-scripts/ifcfg-eth0" file holds the network configuration for the "eth0" adapter. If you have multiple network adapters, you would expect additional configuration files (eth1, eth2 etc.). The following example contains the configuration for a DHCP adapter.
The "/etc/hosts" file contains information for local name resolution.
The "/etc/resolv.conf" file is used to configure the location of the DNS servers to be used for name resolution. There can be multiple "nameserver" lines, one for each nameserver.
The "/etc/sysconfig/network-scripts" directory contains a number of network related scripts and commands. The ifdown and ifup commands are used to stop and start the specified network adapters.
The current network settings are displayed using the ifconfig command.
https://serhatcelik.wordpress.com/2021/02/15/step-by-step-oracle-19c-rac-installation-on-oracle-linux-7-9/
https://serhatcelik.wordpress.com/2021/02/18/step-by-step-oracle-19c-rac-installation-on-oracle-linux-7-9-part-2/
https://serhatcelik.wordpress.com/2021/02/20/step-by-step-oracle-19c-rac-installation-on-oracle-linux-7-9-part-3-database/
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/networking_guide/sec-configuring_ip_networking_with_ifcg_files
https://oracle-base.com/articles/linux/linux-network-configuration#:~:text=The%20%22%2Fetc%2Fsysconfig%2Fnetwork%2Dscripts%2Fifcfg,configuration%20for%20a%20DHCP%20adapter.
In short: SID = the unique name of your DB, ServiceName = the alias used when connecting.
SERVICE_NAMES specifies one or more names by which clients can connect to the instance. The instance registers its service names with the listener. When a client requests a service, the listener determines which instances offer the requested service and routes the client to the appropriate instance.
SID = identifies the database instance (database name + instance number). So if your database name is somedb and your instance number is 3, then your SID is somedb3.
DB Name = Name of the database (database can be shared b/t multiple instances)
DB Domain = Usually the same as your company domain (somecompany.com)
Global Database Name = Database name + database domain (somedb.somecompany.com)
Service Name = A "connector" to one or more instances. It is often useful to create additional service names in a RAC environment since the service can be modified to use particular SIDs as primary or secondary connections, or to not use certain SIDs at all.
Service Alias = An alias to the service name (just like a CNAME, etc). Say you make your service name something meaningful to the dba, but perhaps it's a bit esoteric. Create a service alias and name it something that will be meaningful to the user.
Instance name = same as SID
