Thursday, September 12, 2019

Oracle database Recovery Research Paper Example | Topics and Well Written Essays - 1750 words

Oracle database Recovery - Research Paper Example The mounting technique helps a database to read files without opening them. The Oracle tries to initialize each and every control files available in the initORACLE_SID.ora  file, if the files are replicated. The any control file is broken the mounting techniques fails. In order to configure a database, first we need to run svrmgrl, and secondly connect it to the database and finally enter (Preston, 1999): startup mount. â€Å"$  svrmgrl SVRMGR >  connect internal; Connected. SVRMGR >  startup mount; Statement processed† If the above procedure accomplished then the output must seems to be like this (Preston, 1999): â€Å"SVRMGR >  startup mount; ORACLE instance started. Total System Global Area 5130648 bytes Fixed Size 44924 bytes Variable Size 4151836 bytes Database Buffers 409600 bytes Redo Buffers 524288 bytes Database mounted† The mounting of the database if turn successful then step 10 must be performed. On the contrary, if the mounting process fails than the output seems like this (Preston, 1999): â€Å"SVRMGR >  startup mount; Total System Global Area 5130648 bytes Fixed Size 44924 bytes Variable Size 4151836 bytes Database Buffer to s 409600 bytes Redo Buffers 524288 bytes ORACLE instance started. ... Moreover, these files can easily be recreated if required. The core element regarding data and information portrays impact on more than one control files that are missing. This is due to the fact that Oracle abandons the mounting files that come across failure. Hence, the files are missing if the mounting procedure fails. Therefore, before taking any action, first we need to determine the seriousness of the problem. This can be done by researching on the situation. Initial research includes the names of the missing control files by doing configORACLE_SID.ora  file subsequently to the word  control files. It looks somewhat like this (Preston, 1999): â€Å"control_files = (/db/Oracle/a/oradata/crash/control01.ctl, /db/Oracle/b/oradata/crash/control02.ctl, /db/Oracle/c/oradata/crash/control03.ctl)† (Rajan, 2006 ) The control file name that is criticized by Oracle should be found. This can be found by searching for this phrase control file that is maintained in the alert logs. Moreover, the alert log can be found in particular location such as ‘background_dump_dest’ and ‘configinstance.ora’ file. In general, it is present in the file named as ORACLE_BASE/ORACLE_SID/admin/bdump’directory. A file named as ‘alert_ORACLE_SID.log’ must be present in directory. The error looks like this (Preston, 1999): alter database mount exclusive ORA-00202: controlfile: '/db/a/oradata/crash/control01.ctl' ORA-27037: unable to obtain file status SVR4 Error: 2: No such file or directory† The name of all the control files along with crashed file names, it is relatively easier to analyze the complexity of the issue. This can be achieved by listing control files with their comparison with the size and time of any change and

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