Programming Pig

Appendix A. Built-in User Defined Functions and Piggybank

This appendix covers UDFs that come as part of the Pig distribution, including built-in UDFs and user-contributed UDFs in Piggybank.

Built-in UDFs

Pig comes prepackaged with many UDFs that can be used directly in Pig without using register or define. These include load, store, evaluation, and filter functions.

Built-in Load and Store Functions

Pig’s built-in load functions are listed in Table A-1; Table A-2 lists the store functions.

Table A-1. Load functions

Function	Location String indicates	Constructor arguments	Description
HBaseStorage	HBase table	The first argument is a string describing column family and column to Pig field mapping. The second is an option string (optional).	Load data from HBase (see HBase).
PigStorage	HDFS file	The first argument is a field separator (optional; defaults to Tab).	Load text data from HDFS (see Load).
TextLoader	HDFS file	None.	Reads lines of text, each line as a tuple with one chararray field.

Table A-2. Store functions

Function	Location String indicates	Constructor arguments	Description
HBaseStorage	HBase table	The first argument is a string describing Pig field to HBase column family and column mapping. The second is an option string (optional).	Store data to HBase (see HBase).
PigStorage	HDFS file	The first argument is a field separator (optional; defaults to Tab).	Store text to HDFS in text format (see Store).

Built-in Evaluation and Filter Functions

The evaluation functions can be divided into math functions that ...