Pig Latin – Relational Operations
The following table describes the relational operators of Pig Latin.
| Operator | Description |
|---|---|
| Loading and Storing | |
| LOAD | To Load the data from the file system (local/HDFS) into a relation. |
| STORE | To save a relation to the file system (local/HDFS). |
| Filtering | |
| FILTER | To remove unwanted rows from a relation. |
| DISTINCT | To remove duplicate rows from a relation. |
| FOREACH, GENERATE | To generate data transformations based on columns of data. |
| STREAM | To transform a relation using an external program. |
| Grouping and Joining | |
| JOIN | To join two or more relations. |
| COGROUP | To group the data in two or more relations. |
| GROUP | To group the data in a single relation. |
| CROSS | To create the cross product of two or more relations. |
| Sorting | |
| ORDER | To arrange a relation in a sorted order based on one or more fields (ascending or descending). |
| LIMIT | To get a limited number of tuples from a relation. |
| Combining and Splitting | |
| UNION | To combine two or more relations into a single relation. |
| SPLIT | To split a single relation into two or more relations. |
| Diagnostic Operators | |
| DUMP | To print the contents of a relation on the console. |
| DESCRIBE | To describe the schema of a relation. |
| EXPLAIN | To view the logical, physical, or MapReduce execution plans to compute a relation. |
| ILLUSTRATE | To view the step-by-step execution of a series of statements. |