SQL> show parameter memory_target
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
memory_target big integer 0
SQL> show parameter target
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
archive_lag_target integer 0
db_big_table_cache_percent_target string 0
db_flashback_retention_target integer 1440
fast_start_io_target integer 0
fast_start_mttr_target integer 0
memory_max_target big integer 0
memory_target big integer 0
parallel_servers_target integer 80
pga_aggregate_target big integer 1573M
sga_target big integer 4720M
target_pdbs integer 9
SQL> alter system set memory_target=1521m scope=spfile;
System altered.
SQL> startup force;
ORA-00838: Specified value of MEMORY_TARGET is too small, needs to be at least 6304M
ORA-01078: failure in processing system parameters
[oracle@dbserver dbs]$ scp initorclcdb.ora oracle@192.168.133.123:/u01/app/oracle/product/19.12.0/db_1/dbs
说明：此处是将之前克隆的服务器上的参数文件传到出现异常的服务器上，其实参数文件是可以通过告警日志文件找到相关参数来重建的。
[oracle@dbserver dbs]$ cat initorclcdb.ora
orclcdb.__data_transfer_cache_size=0
orclcdb.__db_cache_size=3841982464
orclcdb.__inmemory_ext_roarea=0
orclcdb.__inmemory_ext_rwarea=0
orclcdb.__java_pool_size=0
orclcdb.__large_pool_size=16777216
orclcdb.__oracle_base='/u01/app/oracle'#ORACLE_BASE set from environment
orclcdb.__pga_aggregate_target=1660944384
orclcdb.__sga_target=4949278720
orclcdb.__shared_io_pool_size=134217728
orclcdb.__shared_pool_size=905969664
orclcdb.__streams_pool_size=33554432
orclcdb.__unified_pga_pool_size=0
*.audit_file_dest='/u01/app/oracle/admin/orclcdb/adump'
*.audit_trail='db'
*.compatible='19.0.0'
*.control_files='+DATA/ORCLCDB/CONTROLFILE/current.261.1089511797','+FRA/ORCLCDB/CONTROLFILE/current.256.1089511797'
*.db_block_size=8192
*.db_create_file_dest='+DATA'
*.db_name='orclcdb'
*.db_recovery_file_dest='+FRA'
*.db_recovery_file_dest_size=10000m
*.diagnostic_dest='/u01/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=orclcdbXDB)'
*.enable_pluggable_database=true
*.local_listener='LISTENER_ORCLCDB'
*.nls_language='AMERICAN'
*.nls_territory='AMERICA'
*.open_cursors=300
*.pga_aggregate_target=1573m
*.processes=320
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_target=4716m
*.undo_tablespace='UNDOTBS1'
SQL> startup nomount pfile='/u01/app/oracle/product/19.12.0/db_1/dbs/initorclcdb.ora';
ORACLE instance started.
Total System Global Area 4949277288 bytes
Fixed Size 9144936 bytes
Variable Size 956301312 bytes
Database Buffers 3976200192 bytes
Redo Buffers 7630848 bytes
SQL> create spfile='/u01/app/oracle/product/19.12.0/db_1/dbs/spfileorclcdb.ora' from pfile='/u01/app/oracle/product/19.12.0/db_1/dbs/initorclcdb.ora';
File created.
SQL> alter database mount;
Database altered.
SQL> alter database open;
Database altered.
说明：在创建spfile时，如果不指定路径，那么每次启动数据库都要指定pfile路径。
