Oracle Database / Connections & Oracle Net
Find a mismatched Oracle client home on Linux
SQL*Plus may connect while the application fails because they load different Oracle clients. Inspect the executable and configuration location in the failing process environment.
Environment and inputs: Oracle Database 19c baseline · SQL*Plus-compatible SQL unless RMAN, DGMGRL, ADRCI or a host shell is specified. Check release, patch level, edition and container first.
Start with this diagnostic
Use the stated SQL, RMAN, DGMGRL or host shell and replace sample names with approved targets. DBA and V$ views need authorized catalog access in the correct container. Do not grant broad privileges for an example.
command -v sqlplus
command -v tnsping
printenv ORACLE_HOME TNS_ADMINRead the result
In a Linux shell, these show the selected utilities and two configuration-related variables. They do not prove which libraries an already-running application loaded.
Resolve and verify
Compare the service's approved startup environment and loaded driver with the tested terminal. Update only the intended service environment, then recycle its connections through the normal change process.
Operational precautions
Do not dump the entire environment because it may contain secrets. Java thin drivers do not necessarily use the same Oracle home as native clients.