In evaluating the basics of data validation, generalizations can be made regarding the different types of validation, according to the scope, complexity, and purpose of the various validation operations to be carried out.
For example: Data type validation is customarily carried out on one or more simple data fields.
If the backup validation discovers corrupt blocks, then RMAN updates the .
After a corrupt block is repaired, the row identifying this block is deleted from the view.
Check constraints are used to make certain that a statement about the data is true for all rows in a table.
In computer science, data validation is the process of ensuring that a program operates on clean, correct and useful data.
It uses routines, often called "validation rules" "validation constraints" or "check routines", that check for correctness, meaningfulness, and security of data that are input to the system.
When the database reads the block from disk later, it recomputes the checksum and compares it to the stored value.
If the values do not match, then the block is corrupt.