We’ll corrupt a block on a datafile and try to restore it via RMAN. First let’s create a sample tablespace:

Then let’s create a table in this tablespace and insert a sample row:

Now we need to find the block number of this record (so we can corrupt it):

Before we corrupt the datablock, we’ll take a full backup.

After the backup completed, we’ll fill this block with zeros at the OS level.

I know thar BLOCK_SIZE of my database is 8K but let’s check it to be sure:

Now let’s corrupt the block:

Now we’ll query the table after flushing buffer cache:

Ok now let’s fix it! First we need to list corrupted blocks:

Let’s test it: