How to perform joins in Apache hive

Question

Hey,

Can anyone explain join operation in hive. I am new to hive so not familiar with this.

Answer 1

Hey,

Join operation will work always with two tables.There are some following joins to perform in hive, which are as follows:

1. INNER JOIN – Select records that have matching values in both tables.
2. LEFT JOIN (LEFT OUTER JOIN) – Returns all the values from the left table, plus the matched values from the right table, or NULL in case of no matching join predicate.
3. RIGHT JOIN (RIGHT OUTER JOIN) A RIGHT JOIN returns all the values from the right table, plus the matched values from the left table, or NULL in case of no matching join predicate
4. FULL JOIN (FULL OUTER JOIN) – Selects all records that match either left or right table records.
5. LEFT SEMI JOIN: Only returns the records from the left-hand table.