In Database Management System (DBMS), data is represented in a tabular form through attributes and tuples i.e., columns and rows. There are various operations (insert, delete, update, modify, etc.) that we can perform on tables. One such operation is JOIN. When we combine two tables into one, we call it a join and it is denoted by ⨝. Spurious Tuples: Spurious Tuples are those rows in a table, which occur as a result of joining two tables in the wrong manner. They are extra tuples (rows) that might not be required. If a relation is denoted by R, and its decomposed relations are denoted by R1, R2, R3…Rn, then, the condition for not getting any Spurious Tuple is denoted by,
R1 ⨝ R2 ⨝ R3 .... ⨝ Rn = R
Whereas the condition for getting Spurious Tuples is denoted by,
R ⊂ R1 ⨝ R2 ⨝ R3 .... ⨝ Rn
Example-1: Example to check if the given relation contains Spurious Tuples. Let R be a Relation, and R1 and R2 be relations that we get after decomposing R.