Configure the network environment to allow connections to multiple databases.
These notes are from "2 Identifying and Accessing the Database".
For "About Dedicated Server Processes" in "Understanding Service Handlers":
In order for remote clients to connect to dedicated servers, the listener and the database instance must be running on the same computer.
Because the listener spawns a new process for a dedicated server, this can only be done on the same server. Whereas, for a shared server, the listener merely provides the location of an already created process. This allows listeners to point to remote shared servers.
"About Database Resident Connection Pooling"
Clients obtaining connections out of the database resident connection pool are persistently connected to a background process, the connection broker, instead of the dedicated servers. The connection broker implements the pool functionality and performs the multiplexing of inbound connections from the clients to a pool of dedicated servers with sessions.
"Entering a Connect String" in "Understanding Naming Methods" says:
On most operating systems, you can define a default connect identifier. When using the default, a connect identifier does not need to be specified in the connect string. To define a default connect identifier, use the TWO_TASK environment variable on Linux and UNIX platforms or the LOCAL environment variable or registry entry on Microsoft Windows.
These notes are from "4 Understanding the Communication Layers".
Two Task Common (TTC) is the presentation layer which manages character set conversions.
Transparent Network Substrate (TNS) is the single common interface for OSI transport and network layer protocols.
JDBC OCI driver (type 2) allows mapping between Java and OCI.
JDBC Thin driver (type 4) uses:
Sockets Direct Protocol (SDP) is for Infiband only. Messaging burden has been moved to network hardware.