手误修改了spfile参数文件
数据库启动使用的是SPFILE，修改参数文件误修改了SPFILEORCL.ora。导致数据库启动失败。
```
SQL> startup
ORA-01078: failure in processing system parameters
LRM-00109: could not open parameter file ‘/u01/app/oracle/product/19.3.0/dbhome_1/dbs/initorcl.ora’
```
解决方案
使用strings命令将spfile参数重定向到initorcl.ora。在启动数据库服务。
$ strings spfileorcl.ora >>initorcl.ora
$ sqlplus / as sysdba
SQL*Plus: Release 19.0.0.0.0 - Production on Wed Apr 17 15:56:38 2024
Version 19.3.0.0.0
Copyright (c) 1982, 2019, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup pfile='/u01/app/oracle/product/19.3.0/dbhome_1/dbs/initorcl.ora'
ORACLE instance started.
Total System Global Area 2147481656 bytes
Fixed Size 8898616 bytes
Variable Size 1426063360 bytes
Database Buffers 704643072 bytes
Redo Buffers 7876608 bytes
Database mounted.
Database opened.
重建SPFILE
SQL> create spfile from pfile;
File created.
重启数据库，使用SPFILE启动，数据库启动参数优先级 SPFILE>initorcl.ora
调整手动修改参数
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 64
pga_aggregate_target big integer 512M
sga_target big integer 1536M
target_pdbs integer 0
SQL> alter system set memory_max_target=1024 scope=spfile;
System altered.
SQL>
SQL> show parameter spfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string /u01/app/oracle/product/19.3.0
/dbhome_1/dbs/spfileorcl.ora
