Hi, If you look at the source code of REPLACE, what it does is basically:
String source = "[02/Aug/2012:05:01:17"; > String target ="["; > String replaceWith = ""; > return source.replaceAll(source, target, replaceWith); Note that Java String.replaceAll() takes a regular expression for the 2nd parameter (i.e. target), and "[" is a special character. To use it as is, you have to escape it, so in your Pig script, you should do: REPLACE(date,'\\[','') Now regarding the result that you're seeing, it looks like whatever exception is thrown inside REPLACE is swallowed rather than makes the job fail, and null is returned: try{ > ... > }catch(Exception e){ > warn("Failed to process input; error - " + e.getMessage(), > PigWarning.*UDF_WARNING_1*); > return null; > } But I do see the following message at the end of the job status: 2012-08-17 16:51:25,061 [main] WARN org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - Encountered *Warning UDF_WARNING_1* 1 time(s) I must admit that this is not very visible though. Thanks, Cheolsoo On Mon, Aug 13, 2012 at 10:03 PM, MiaoMiao <liy...@gmail.com> wrote: > I used pig to do some ETL job, but met with a strange bug of the > built-in REPLACE function. > > After I replace '[' with '' in '[02/Aug/2012:05:01:17' , the whole > string just went blank. > > Here I posted some info that may help debug. > > My pig version is: Apache Pig version 0.11.0-SNAPSHOT (r1364475) > compiled Jul 23 2012, 10:30:53 > > The original text file: > ip.ip.ip.ip - - [02/Aug/2012:05:01:17 -0600] "GET > /player.php/sid/XNDM0Njk3MjEy/v.swf HTTP/1.1" 302 26 > > The whole pig script is : > read = load '/home/test/apacheLog' > using PigStorage(' ') > as ( > ip:chararray > , indentity:chararray > , name:chararray > , date:chararray > , timezone:chararray > , method:chararray > , path:chararray > , protocol:chararray > , status:chararray > , size:chararray > ); > dump read; > > --(ip.ip.ip.ip,-,-,[02/Aug/2012:05:01:17,-0600],"GET,/player.php/sid/XNDM0Njk3MjEy/v.swf,HTTP/1.1",302,26) > data = foreach read generate > ip > , REPLACE(date,'[','') > , REPLACE(timezone,']','') > , REPLACE(method,'"','') > , path > , REPLACE(protocol,'"','') > , status > , size; > describe data; > --data: {ip: chararray,date: chararray,timezone: chararray,method: > chararray,path: chararray,protocol: chararray,status: chararray,size: > chararray} > dump data; > > --(ip.ip.ip.ip,,-0600,GET,/player.php/sid/XNDM0Njk3MjEy/v.swf,HTTP/1.1,302,26) >