ORCL = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = dbhost.example.com)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = orcl.example.com) ) ) Connect with SQL*Plus:

| Variable | Description | Example | |----------|-------------|---------| | ORACLE_HOME | Instant Client directory | /opt/oracle/instantclient_19c | | PATH or LD_LIBRARY_PATH | Library search path | Include the Instant Client folder | | TNS_ADMIN | Location of tnsnames.ora | /etc/oracle | | NLS_LANG | Character set/language | AMERICAN_AMERICA.AL32UTF8 | Using TNS Alias (tnsnames.ora) Create a tnsnames.ora file in $TNS_ADMIN :

What is Oracle Instant Client? Oracle Instant Client is a free, easy-to-install, and lightweight set of libraries and tools that enables applications to connect to local or remote Oracle Databases. It provides the necessary network connectivity and data access without requiring a full Oracle Database installation.