UDF execution procedure in hive

Question

I have created a UDF for hive named as Zodiac then added the JAR file and created as temporary function in hive.

I have a table named Student with 50 rows in Hive database

When I give the following command in hive command prompt,

Select Zodiac(Dateofbirth) from Student;

It returns the proper output. My question is, when I'm giving the above command, Will it pass the 50 records as arguments at the same time or will it executes the above SELECT statement for each row of the table.

thanks in advance.

Answer 1

In your case Hive will call Zodiac UDF's evaluate method exactly 50 times.

You can add logging to the evaluate method and check it by yourself.