· Joins are used to join two or more tables to extract the data
· Joins are used to retrieve the relational based data from the tables
· Joins mainly used to filter the records from the multiple tables
· Joins can be used to retrieve the matching and non-matching data
· There are different types of joins available in the RDBMS like equi, non-equi, cartitian/cross join, left outer, right outer.
· Joins are used to join the table columns with specific values or other table columns.
· Join allows duplicates
· Union is a set function
· Union is used to combine 2 or more select query result set outputs
· Union removes the duplicate rows from the result set
· Number and names of columns should match in all the select queries
· Union operator cannot be used in create view statement.