Oracle spfile damaged during online modification

Oracle spfile is damaged when it is modified online. A few days ago, I was just getting started with ORACLE and knew that the database must be running in archive mode: I had to change it to archive mode: first query SQL> select name, log_mode from v $ database; NAME LOG_MODE --------- ------------ iptvbms archivelogsql> archive log listDatabase log mode Archive Mode -- indicates that the Automatic archival EnabledArchive destination has been archived online log sequence 7517 Next log sequence to archive 7523 Current log sequence 75231. SQL> al Ter system set log_archive_dest_1 = 'location =/oracle/oracle10g/log/archive_log '; this statement determines the path of the archived log. In fact, Oracle 10g can generate multiple identical logs, store multiple locations to prevent unexpected events. For example, you can use the following statement to add another log location: SQL> alter system set log_archive_dest_2 = 'location =/oracle/oracle10g/log2/archive_log '; 2. shut down Database SQL> shutdown immediate 3. start the data mount status: SQL> startup mount; 4. Change the database to archive mode: SQL> alter database archivelog; 5. open the database and query: SQL> alter database open; how can I learn parameter files one day? You can also back up SQL> create pfile = '/opt/oracle // app/oracle/product/11.1/db/dbs/orabak/initiptvbms. ora 'from spfile; today to SGA_TARGET SGA_MAX_SIZE when the wrong order, no M and other units, the startup times the error of SQL> shutdown immediate consistency close, the error is reported as follows ORA-00851: SGA_MAX_SIZE 1577058304 cannot be set to more than MEMORY_TARGET cannot be solved by using the online method? To enable database startup, use pfile to start: SQL code 1. SQL> startup pfile =/opt/oracle/app/oracle/admin/iptvbms/pfile/init. ora.4272011104615 SQL> startup pfile = '/opt/oracle/app/oracle/admin/iptvbms/pfile/init. ora.4272011104615 'create spfile through pfile: SQL code 1. create spfile = '/opt/oracle/app/oracle/product/11.1/db/dbs/spfileiptvbms. ora 'from pfile = '/opt/oracle/app/oracle/admin/iptvbms/pfile/init. ora.4272011104615 '; can't it be solved ?? After thinking about it for half a day, I found a backup Summary after half a day: ORACLE must be running in archive mode and regularly back up relevant files, including parameter files and control files, and data files; 1. because my library has N multiple libraries, so you need to set the environment variable export ORACLE_SID = iptvbmsRefer to the SQL * Plus User's Guide and Reference for more information.2. login oracle @ iptv-app2: ~> Sqlplus/as sysdbaSQL * Plus: Release 11.1.0.6.0-Production on Fri Apr 12 11:38:57 2013 Copyright (c) 1982,200 7, Oracle. all rights reserved. connected to an idle instance.3. use the backup to start the database to the NOMOUNT status SQL> startup pfile = '/opt/oracle // app/oracle/product/11.1/db/dbs/orabak/initiptvbms. ora 'nomount; ORACLE instance started. total System Global Area 559534080 bytesFixed Size 2146312 bytesVariable Size 339742712 BytesDatabase Buffers 209715200 bytesRedo Buffers 7929856 bytes4. Remember to restore SPFILE back to SQL> create spfile from pfile = '/opt/oracle // app/oracle/product/11.1/db/dbs/orabak/initiptvbms. ora '; File created.5. start to the MOUNT status SQL> alter database mount; Database altered.6. Open database SQL> alter Database open; database altered. SQL> create spfile from pfile = '/opt/oracle // app/oracle/product/11.1/db/dbs/orabak/initiptvbms. ora '; File created.7. Verify that SPFILE has been OKSQL> ho ls/opt/oracle/app/oracle/product/11.1/db/dbs/spfileiptvbms */opt/oracle/app/oracle/product/11.1/ db/dbs/spfileiptvbms. ora 8. Restart the Database SQL> shutdown immediateDatabase closed. Database dismounted. ORACLE instance shut down. You may be experienced