网站二级菜单模板,湖南电子科技网站建设,做php网站前端价格,网站开发需求网DB_RECOVERY_FILE_DEST参数是默认的flashrecovery area的路径#xff0c;里面存放有归档日志、闪回日志以及rman的备份文件等文件。LOG_ARCHIVE_DEST_n参数是存放归档日志的路径#xff0c;n表示1~10的一个整数#xff0c;由于归档日志在recovery的时候担当了重要的角色里面存放有归档日志、闪回日志以及rman的备份文件等文件。LOG_ARCHIVE_DEST_n参数是存放归档日志的路径n表示1~10的一个整数由于归档日志在recovery的时候担当了重要的角色所以我们可以设置多个归档目录(最多可以设置10个)。这种情况下联机日志在归档时会在不同的目录下都会生成有一个相同的归档文件通过冗余的来保证归档日志的安全。系统默认的情况是以DB_RECOVERY_FILE_DEST定义的目录来存放归档日志。但是课上演示的时候老师已经设置了log_archive_dest_1、log_archive_dest_2和log_archive_dest_3三个参数。我现在将这三个参数修改回去让系统使用默认的DB_RECOVERY_FILE_DEST目录来存放归档日志。经过下面的操作发现提示找不到归档的目录。SQL alter system set log_archive_dest_1;SQL alter system set log_archive_dest_2;SQL alter system set log_archive_dest_3;SQL alter system archive log current;alter system archive log current*ERROR at line 1:ORA-16014: log 2 sequence# 50 not archived, noavailable destinationsORA-00312: online log 2 thread 1:/opt/ora10g/oradata/orcl/redo02.logSQL archive log list;Database log modeArchive ModeAutomatic archivalEnabledArchive destination?/dbs/archOldest online log sequence49Next log sequence to archive50Current log sequence51解决办法我们暂时先指定一个目录来存放归档日志。然后再修改三个log_archive_dest_n的系统参数时指定好scope为spfile重启实例即可。SQL alter system set log_archive_dest_1location/logs/log_1;SQL alter system archive log current;System altered.SQL alter system set log_archive_dest_1 scopespfile;SQL alter system set log_archive_dest_2 scopespfile;SQL alter system set log_archive_dest_3 scopespfile;SQL startup forceORACLE instance started.Total System Global Area285212672 bytesFixed Size1218992 bytesVariable Size104859216 bytesDatabase Buffers176160768 bytesRedo Buffers2973696 bytesDatabase mounted.Database opened.查看一下现在使用的归档的目录已经成功改回为了DB_RECOVERY_FILE_DEST。SQL archive log list;Database log modeArchive ModeAutomatic archivalEnabledArchive destinationUSE_DB_RECOVERY_FILE_DESTOldest online log sequence51Next log sequence to archive53Current log sequence53最后再查看一下log_archive_dest_n参数这些参数都没有被设置了均为空SQL show parameter log_archive_destNAMETYPEVALUE------------------------------------ -----------------------------------------log_archive_deststringlog_archive_dest_1stringlog_archive_dest_10stringlog_archive_dest_2stringlog_archive_dest_3stringlog_archive_dest_4stringlog_archive_dest_5stringlog_archive_dest_6stringlog_archive_dest_7stringlog_archive_dest_8stringlog_archive_dest_9string小结log_archive_dest_n与DB_RECOVERY_FILE_DEST参数都可以用来存放归档日志但二者的关系是不设置log_archive_dest_n时使用DB_RECOVERY_FILE_DEST来存文件当设置了log_archive_dest_n时则使用log_archive_dest_n来存放归档日志。下面我们再对log_archive_dest_n进行设置让DB_RECOVERY_FILE_DEST“失效”。SQLaltersystem set log_archive_dest_1location/logs/log_1 scopespfile;SQLaltersystem set log_archive_dest_2location/logs/log_2 scopespfile;SQLaltersystem set log_archive_dest_3location/logs/log_3 scopespfile;SQLstartup forceORACLE instancestarted.Total SystemGlobal Area 285212672 bytesFixed Size1218992 bytesVariableSize109053520 bytesDatabaseBuffers171966464 bytesRedoBuffers2973696 bytesDatabasemounted.Database opened.我们进行下手动归档SQLalter system archive log current;查看下系统时间发现三个目录下都已经有了最新的归档日志[rootlocalhostlogs]$ dateWed Sep1 10:48:39 CST 2010[rootlocalhostlogs]# ll -t log_1-rw-r----- 1oracle oinstall280576 Sep1 10:48 1_54_723037014.dbf[rootlocalhostlogs]# ll -t log_2-rw-r----- 1oracle oinstall280576 Sep1 10:48 1_54_723037014.dbf[rootlocalhostlogs]# ll -t log_3-rw-r----- 1oracle oinstall280576 Sep1 10:48 1_54_723037014.dbf而DB_RECOVERY_FILE_DEST目录下已经不再会存放新的归档日志了[oraclelocalhostarchivelog]$ ll 2010_09_01/-rw-r----- 1oracle oinstall 20992 Sep1 10:07o1_mf_1_52_67vfc7q5_.arc