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What is Pig ???

What is Pig ???. Why Pig ???. MapReduce is difficult to program. It only has two phases. Put the logic at the phase. Too many lines of code even for simple logic. Need Jobchain for long dataflow. Pig Features???. High level processing layer on top of MapReduce .

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What is Pig ???

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  1. What is Pig ???

  2. Why Pig ??? • MapReduce is difficult to program. • It only has two phases. • Put the logic at the phase. • Too many lines of code even for simple logic. • Need Jobchain for long dataflow.

  3. Pig Features??? • High level processing layer on top of MapReduce. • Pig has a high-level data processing data-flow language. Provides a sequence of steps where each step is single high level data transformation. • No metadata or schema required for data. • Simplifies joining data and chaining jobs together. • Pig latin includes operators for many of the traditional data operations. • Supports UDF

  4. Comparing MapReduce and Pig

  5. Running Pig • Three ways to run pig • Grunt Interactive Shell • Through a script file • Embedded queries inside java program • Pig Data Types • Int, long, float, double, chararray, bytearray • Tuple , Bag, Map

  6. Pig Latin(1/4) grunt> log = LOAD 'tutorial/data/excite-small.log' ➥ AS (user:chararray, time:long, query:chararray); grunt> grpd = GROUP log BY user; grunt> cntd = FOREACH grpd GENERATE group, COUNT(log); grunt> STORE cntd INTO 'output';

  7. Pig Latin(2/4) grunt> DESCRIBE log; log: {user: chararray,time: long,query: chararray} grunt> DESCRIBE grpd; grpd: {group: chararray,log: {user: chararray,time: long,query: chararray}} grunt> DESCRIBE cntd; cntd: {group: chararray,long}

  8. Pig Latin(3/4) grunt> ILLUSTRATE cntd; | log | user: bytearray | time: bytearray | query: bytearray | | | 0567639EB8F3751C | 970916161410 | "conano'brien" | | | |0567639EB8F3751C | 970916161413 | "conano'brien" | | | |972F13CE9A8E2FA3 | 970916063540 | finger AND download | | ------------------------------------------------------------------------------------- | log | user: chararray | time: long | query: chararray | | | 0567639EB8F3751C | 970916161410 | "conano'brien" | | | |0567639EB8F3751C | 970916161413 | "conano'brien" | | | 972F13CE9A8E2FA3 | 970916063540 | finger AND download | | -------------------------------------------------------------------------------------- | grpd | group: chararray | log: bag({user: chararray,time: long, query: chararray}) | | | 0567639EB8F3751C | {(0567639EB8F3751C, 970916161410, "conano'brien"), (0567639EB8F3751C,970916161413, "conano'brien")} || | | 972F13CE9A8E2FA3 | {(972F13CE9A8E2FA3, 970916063540, finger AND download)} || --------------------------------------------------------------------------------------------------------------------- | cntd | group: chararray | long | | | 0567639EB8F3751C | 2 | | | | 972F13CE9A8E2FA3 | 1 | |

  9. Pig Latin(4/4) Built-in function in Pig Latin AVG, CONCAT, COUNT, DIFF, MAX, MIN, SIZE, SUM, TOKENIZE, IsEmpty Relational Operators in Pig Latin SPLIT, UNION, FILTER, DISTINCT, SAMPLE, FOREACH, JOIN, GROUP, COGROUP

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