Today I was not able to connect to 10g Oracle database from SQL*Plus on a client PC.
I tried to connect to the database by running sqlplus apps/apps@oracle
Error message:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
SVR4 Error: 2: No such file or directory
From the db server itself, I was able to connect to the database using OS authentication.
When I run ps -ef, I found that the background process are all using ORACLE instead of “oracle”
oracledb 22187 1 0 10:22:16 ? 0:02 ora_smon_ORACLE
oracledb 22189 1 0 10:22:16 ? 0:00 ora_reco_ORACLE
oracledb 22191 1 0 10:22:16 ? 0:01 ora_cjq0_ORACLE
oracledb 22199 1 0 10:22:17 ? 0:00 ora_p000_ORACLE
oracledb 22181 1 0 10:22:16 ? 0:00 ora_dbw0_ORACLE
oracledb 22179 1 0 10:22:16 ? 0:00 ora_mman_ORACLE
oracledb 22203 1 0 10:22:17 ? 0:00 ora_p002_ORACLE
oracledb 22185 1 0 10:22:16 ? 0:01 ora_ckpt_ORACLE
The listener name was “oracle”. To fix the connection problem, shutdown the listener, edit listener.ora and change occurrence of “oracle” to “ORACLE”. Restart the listener.
Test connection from SQL*Plus on PC client again.
