DB version : 19c
OS : RHEL 7.9
DB Type: Creating a stand alone CDB (not RAC)
I manually created a CDB using scripts generated by dbca.
I specified the database name as db_abcd in the following files
1. In the CREATE DATABASE command (in **CreateDB.sq**l)
2. db_name parameter in init.ora file (spfile was created later out of this init.ora pfile)
When the DB got created (after all the scripts got executed), I can see the following as expected.
SQL> show parameter db_name
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_name string db_abcd
SQL>
SQL> show parameter db_unique_name
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_unique_name string db_abcd
SQL> select NAME, DB_UNIQUE_NAME FROM V$DATABASE;
NAME DB_UNIQUE_NAME
--------- ------------------------------
DB_ABCD db_abcd
But, the instance_name shows up as db_wxyz !
SQL> select instance_name from v$instance;
INSTANCE_NAME
----------------
db_wxyz
But, I hadn't set INSTANCE_NAME in the init.ora file which was used to mount the instance. I am not even sure if there is an INSTANCE_NAME parameter.
Similarly, pmon process for this instance is shows up asora_pmon_db_wxyz. Same goes for other background processes like smon
$ ps -ef | grep pmon
oracle 28429 1 0 21:57 ? 00:00:00 ora_pmon_db_wxyz
/etc/oratab file also lists db_wxyz
db_wxyz:/u01/app/oracle/product/19.0.0/db_1:N
This name (db_wxyz) was visible with pmon process right from the beginning of the DB creation. i.e. When the instance was mounted in NOMOUNT state before the CREATE DATABASE command was executed.
But, db_name parameter was clearly specified as db_abcd in the init.ora file used to mount the instance.
Any idea which configuration file used during DB creation would have caused this mismatch ? Is this some 19c specific thing ?