Hi Ruslan,
Thanks for the response.I think I have made a mistake.Actually I
just want the top 5 records each time.I don't have any sorting
requirements.
Regards,
Mohammad Tariq
On Mon, May 21, 2012 at 9:31 PM, Ruslan Al-fakikh
<ruslan.al-fak...@jalent.ru> wrote:
> Hey Mohammad,
>
> Here
> c = TOP(5,3,a);
> you say: take 5 records out of a that have the biggest values in the third
> column. Do you really need that sorting by the third column?
>
> -----Original Message-----
> From: Mohammad Tariq [mailto:donta...@gmail.com]
> Sent: Monday, May 21, 2012 3:54 PM
> To: user@pig.apache.org
> Subject: How to use TOP?
>
> Hello list,
>
> I have an Hdfs file that has 6 columns that contain some data stored in an
> Hbase table.the data looks like this -
>
> 18.98 2000 1.21 193.46 2.64 58.17
> 52.49 2000.5 4.32 947.11 2.74 64.45
> 115.24 2001 16.8 878.58 2.66 94.49
> 55.55 2001.5 33.03 656.56 2.82 60.76
> 156.14 2002 35.52 83.75 2.6 59.57
> 138.77 2002.5 21.51 105.76 2.62 85.89
> 71.89 2003 27.79 709.01 2.63 85.44
> 59.84 2003.5 32.1 444.82 2.72 70.8
> 103.18 2004 4.09 413.15 2.8 54.37
>
> Now I have to take each record along with its next 4 records and do some
> processing(for example, in the first shot I have to take records 1-5, in the
> next shot I have to take 2-6 and so on)..I am trying to use TOP for this,
> but getting the following error -
>
> 2012-05-21 17:04:30,328 [main] ERROR org.apache.pig.tools.grunt.Grunt
> - ERROR 1200: Pig script failed to parse:
> <line 6, column 37> Invalid scalar projection: parameters : A column needs
> to be projected from a relation for it to be used as a scalar Details at
> logfile: /home/mohammad/pig-0.9.2/logs/pig_1337599211281.log
>
> I am using following commands -
>
> grunt> a = load 'hbase://logdata'
>>> using org.apache.pig.backend.hadoop.hbase.HBaseStorage(
>>> 'cf:DGR cf:HD cf:POR cf:RES cf:RHOB cf:SON', '-loadKey true') as (id,
>>> DGR, HD, POR, RES, RHOB, SON);
> grunt> b = foreach a { c = TOP(5,3,a);
>>> generate flatten(c);
>>> }
>
> Could anyone tell me how to achieve that????Many thanks.
>
> Regards,
> Mohammad Tariq
>
