4 votes 4 votes Does out put of conditional join contains duplicates?I know that it gives distinct in natural join as the projection operator removes duplicate rows. But in conditional join does this thing holds true? Databases databases relational-algebra + – rahul sharma 5 asked Jul 5, 2017 rahul sharma 5 1.7k views answer comment Share Follow See all 3 Comments See all 3 3 Comments reply Shaik Masthan commented Aug 17, 2018 reply Follow Share yes it contains duplicates... https://www.tutorialspoint.com/dbms/database_joins.htm https://www.studytonight.com/dbms/joining-in-sql.php 1 votes 1 votes sachin486 commented Dec 14, 2020 reply Follow Share relation or table is just a set of tuples and as we know from set theory a set doesn’t allow duplicate values 0 votes 0 votes Mohitdas commented Jul 14, 2021 reply Follow Share Set — A set is a mutable unordered collection with no duplicate elements. Tuple — A tuple is an immutable ordered collection that allows duplicate elements. It’s obvious after a cross-product you will get duplicates, conditional joints are performed if we are given a condition both Natural and Conditional joint use Cartesian products and selection, but in the case of natural joint tables with equal to and logical and is used for removing duplicates 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes As we know the conditional join is just an extension of natural join....in conditional join even we perform cross product and apply condition but at last we have to project the attributes which will definitely removes the duplicates.... vamp_vaibhav answered Sep 12, 2017 vamp_vaibhav comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes From Korth book The theta join operation is a variant of the natural-join operation that allows us to combine a selection and a Cartesian product into a single operation So theta join is just a generalized version of natural join, so duplicates will be removed. smsubham answered Sep 24, 2017 smsubham comment Share Follow See all 0 reply Please log in or register to add a comment.