logical server

A higher number of logical servers reduces the "per-server" cost.

Scalable multiserver cluster: different physical and logical servers (web, mail, DNS etc.) are managed from one control panel.

Oracle Clusterware is the software which enables the nodes to communicate with each other, allowing them to form the cluster of nodes which behaves as single logical server.

The obvious advantage would be that search load for the large partitioned table can now be split across multiple servers (logical or physical), not just multiple indexes on the same logical server.

A combination of limits in the DNS and certain protocols, namely the practical size of unfragmented User Datagram Protocol (UDP) packets, resulted in a decision to limit the number of root servers to 13 logical servers.