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Big Data - Apache Pig

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Lesson Description


Lession - #464 Apache pig UDF(User Defined Function)


Pig provides extensive help for user defined functions (UDFs>
as a method for indicating custom handling. Pig UDFs can at present be executed in six dialects: Java, Jython, Python, JavaScript, Ruby and Groovy. The most broad help is accommodated Java functions.

In Apache Pig, we likewise have a Java repository for UDF's named Piggybank. Utilizing Piggybank, we can get to Java UDF's written by different users, and contribute our own Udf's.

Types of UDF's in Java

While writing UDF's utilizing Java, we can make and utilize the following three types of functions −

Channel Functions − The channel functions are utilized as conditions in channel statements. These capacities acknowledge a Pig esteem as info and return a Boolean value.

Eval Functions − The Eval functions are utilized in FOREACH-GENERATE statements. These functions accept a Pig esteem as info and return a Pig result.

Mathematical Functions − The Algebraic functions follow up on internal packs in a FOREACHGENERATE statements. These capacities are utilized to perform full MapReduce procedure on an inward bag.