#tns

Oracle "ORA-12514: listener does not currently know of service": check the name, then the registration

Fix Oracle ORA-12514: list the services the listener knows, use the right service name, open the PDB, register the database with the listener, and fix LOCAL_LISTENER.

Intermediate · 3 min read

ORA-12541

Databases

Oracle "ORA-12541: no listener": start it, or connect to the address it really uses

Fix Oracle ORA-12541 "TNS:no listener" (or "Cannot connect. No listener at host"): start it with lsnrctl, check the host and port, listener.ora, firewalls and Docker.

Beginner · 4 min read