Fixing block corruptions within a Database is always a messy thing. Not because it is not do-able, but it always means some service disruptions combined with a recovery activity of parts of your database.

Regardless you have to analyse and fix the real issue e.q. a dying controller or harddisk, or perhaps a messy memory modul first, in some cases you can speed up time for fixing the issue by just reading out your corrupted table and recreating it.

Connect as a SYSDBA user you can mark the table as needing to skip corrupt blocks with the following command:

This will tell the Oracle Kernel to just read over all corrupted blocks and go on with serving your query until the end.

After you have issued the command about you should be able to issue a CREATE TABLE AS SELECT operation against the corrupt table to extract data from all non-corrupt blocks and/or EXPORT the remaining healty content of the table.

But be aware about you will for sure loose data, which is stored within those corrupt blocks!!!

Once you salvaged the date you should now drop the corrupt table and recreate it from scratch. If for any reason you should wish to keep the damaged table though, you can clear the attribute for a table with this command:

But you will end up with some no longer query able table again!!!

To get a feeling about how much data and blocks you have lost, you can have a look into your trace files. Whenever a session skips a corrupt block due to SKIP_CORRUPT being set then a message is written to the trace file (not the alert log) for each block skipped in the form like this: