Editing Data integrity (section)

=== Logical integrity ===
{{See also|Mutex|Copy-on-write}}

This type of integrity is concerned with the [[correctness (computer science)|correctness]] or [[rationality]] of a piece of data, given a particular context. This includes topics such as [[referential integrity]] and [[entity integrity]] in a [[relational database]] or correctly ignoring impossible sensor data in robotic systems. These concerns involve ensuring that the data "makes sense" given its environment. Challenges include [[software bugs]], design flaws, and human errors. Common methods of ensuring logical integrity include things such as [[check constraint]]s, [[foreign key constraint]]s, program [[assertion (computing)|assertion]]s, and other run-time sanity checks.

Physical and logical integrity often share many challenges such as human errors and design flaws, and both must appropriately deal with concurrent requests to record and retrieve data, the latter of which is entirely a subject on its own.

If a data sector only has a logical error, it can be reused by overwriting it with new data. In case of a physical error, the affected data sector is permanently unusable.