What Do You Mean By Database Anomalies? Explain Briefly With Suitable Example.

A database anomaly is a record in the database that contains data not quite conforming to the intent of the database design. Data can be missing, inconsistent with itself or other data records, ambiguous, or just wrong (incorrect by the measure of objective truth).

An example of a database containing many anomalies is the BlurtIt question database. The idea is that it contain well-formed questions stated in a clear way, with associated answers stated in a clear way. It should be searchable, which means the questions and answers need to be spelled and punctuated correctly. The questions should be sensible (have some grounding in some sort of reality), as should the answers.

An example of a record of questionable quality is this one. The ambiguous word in the question gives rise to one interpretation. Another interpretation would disambiguate the word "starts" as "states", rather than "stars". Either way, the "union" is also ambiguous. Someone searching for an answer as to the number of stars or states might have difficulty locating this record.

You can read through the list of questions asked each day and find many that have questionable spelling and punctuation and word usage, or are sufficiently incomplete that they cannot be answered sensibly.