数据库运行环境oracle19c，安装后，启动数据库时报错，如下，经排查解决方法记录如下
SQL> startup mount
ORACLE instance started.
Total System Global Area 2415917880 bytes
Fixed Size 8899384 bytes
Variable Size 520093696 bytes
Database Buffers 1879048192 bytes
Redo Buffers 7876608 bytes
ORA-01102: cannot mount database in EXCLUSIVE mode
SQL> exit
Disconnected from Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0
[oracle@oraclelinux db_home]$ cd $ORACLE_HOME/dbs
[oracle@oraclelinux dbs]$ ls sgadef*
ls: 无法访问'sgadef*': 没有那个文件或目录
[oracle@oraclelinux dbs]$ ls
hc_orcl.dat init.ora lkORCL orapworcl spfileorcl.ora
[oracle@oraclelinux dbs]$ ls lk*
lkORCL
[oracle@oraclelinux dbs]$ rm lk*
[oracle@oraclelinux dbs]$ ls lk*
ls: 无法访问'lk*': 没有那个文件或目录
[oracle@oraclelinux dbs]$ ls
hc_orcl.dat init.ora orapworcl spfileorcl.ora
