Symptoms
Database cannot be opened, because a datafile checkpoint is lagging behind from the rest of the datafiles.
Cause A datafile was restored from a previous backup, but archivelogs required to recover the said datafile are missing.
Solution There are 3 options available, as shown below:
Option#1: Restore the database from the same backupset, and then recover it by applying up to the last available archivelog to roll it forward, but any updates to the database after the point-in-time of recovery will be lost.
Option#2: Force open the database by setting the _ALLOW_RESETLOGS_CORRUPTION=TRUE in the init.ora. But there is no 100% guarantee that we can open the database. However, once the database is opened, then you must immediately rebuild the database. Database rebuild means doing the following, namely: (1) perform a full-database export, (2) create a new and separate database, and finally (3) import the recent export dump. Note: When exporting after opening the database with the allow corruption parameters, you should set the Event 10231 before export to extract data from all non-corrupt > blocks in order to be able to import the data successfully. For additional information about Event 10231, please review Note 21205.1 : EVENT: 10231 “skip corrupted blocks on _table_scans_”.
Option#3: Manually extract the data using the Oracle’s Data Unloader (DUL),
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