Restore spfile
Beforehand:
create pfile='/opt/oracle/admin/XE/pfile/init.ora.bkp' from spfile;
After incorrect parameters settings:
startup PFILE=/opt/oracle/admin/XE/pfile/init.ora.bkp create spfile from pfile='/opt/oracle/admin/XE/pfile/init.ora.bkp';
sdmrnv, 2019-07-09 [1.087ms, s]