Apache Pig provides various built-in functions namely eval, load, store, math, string, bag and tuple functions.
Eval Functions
Given below is the list of eval functions provided by Apache Pig.
| S.N. | Function & Description |
|---|---|
| 1 | AVG()To compute the average of the numerical values within a bag. |
| 2 | BagToString()To concatenate the elements of a bag into a string. While concatenating, we can place a delimiter between these values (optional). |
| 3 | CONCAT()To concatenate two or more expressions of same type. |
| 4 | COUNT()To get the number of elements in a bag, while counting the number of tuples in a bag. |
| 5 | COUNT_STAR()It is similar to the COUNT() function. It is used to get the number of elements in a bag. |
| 6 | DIFF()To compare two bags (fields) in a tuple. |
| 7 | IsEmpty()To check if a bag or map is empty. |
| 8 | MAX()To calculate the highest value for a column (numeric values or chararrays) in a single-column bag. |
| 9 | MIN()To get the minimum (lowest) value (numeric or chararray) for a certain column in a single-column bag. |
| 10 | PluckTuple()Using the Pig Latin PluckTuple() function, we can define a string Prefix and filter the columns in a relation that begin with the given prefix. |
| 11 | SIZE()To compute the number of elements based on any Pig data type. |
| 12 | SUBTRACT()To subtract two bags. It takes two bags as inputs and returns a bag which contains the tuples of the first bag that are not in the second bag. |
| 13 | SUM()To get the total of the numeric values of a column in a single-column bag. |
| 14 | TOKENIZE()To split a string (which contains a group of words) in a single tuple and return a bag which contains the output of the split operation. |