Shulou(Shulou.com)06/01 Report--

If the data file of a tablespace is corrupted, in the case of a backup, you can restore the backup of the data file, but you also need to restore the archive file to make the data file reach an up-to-date consistency state. to open the database. If the required archive file is not available, such as being deleted, how do you open the database in this case?

In this case, the database cannot be recovered due to the lack of archiving, but if the data related to the tablespace changes little or no change, you can change the SCN number of the data file header to make it consistent with the System Checkpoint SCN and Datafile Checkpoint SCN numbers, so that Oracle can avoid checking the file, and Oracle will not do media recovery, but only do instance recovery, so that complete recovery can be achieved. Open the database in time.

Generally speaking, there are two ways to promote the SCN number of the data file header: first, use BBED (Block Brower and Editor) to modify the data file header and promote the SCN number to open the database. Second, set the implicit parameter "_ ALLOW_RESETLOGS_CORRUPTION" to TRUE to open the database. This parameter defaults to FALSE. After the database is opened, the parameter should be removed from the parameter file. The command is as follows:

ALTER SYSTEM SET "_ ALLOW_RESETLOGS_CORRUPTION" = TRUE SCOPE=SPFILE;-- skips database consistency check

ALTER SYSTEM RESET "_ ALLOW_RESETLOGS_CORRUPTION" SCOPE=SPFILE SID='*';-- cancels this parameter

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.