Can't you mimic dynamic key support with static keys by making your
map have two static keys 'key' and 'value'?
Alan.
On May 24, 2011, at 3:05 AM, Jameson Li wrote:
OK.OK.I know that just write UDFs.
I have to write UDFs, and see you......
And I still think there should be grammar support for map operation
both
static key and dynamic key.............
Thanks.
2011/5/24 Daniel Dai <[email protected]>
GetKey(m) already get the key, so you can filter the key. For
value, you
may need to put into UDF.
Grammar support for map is based on static key, eg: m#'key1'. Your
use case
is mostly dealing dynamic keys, which you may rely on yourself
currently.
Daniel
-----Original Message----- From: Jameson Li
Sent: Monday, May 23, 2011 7:07 PM
To: Daniel Dai
Cc: [email protected]
Subject: Re: how to operate a map type
And how to filter a map key or a map value? And also only UDF?
b = foreach ruls generate com.company.pig.GetURLContent($0,3,0.1)
as m;
c = filter b by m.key == 'aaa' or m.value> 0.2;
How could I write the code?
Any other way without writing UDF?
And I have a doubt since only writing UDF can operate a map type,
why not
have the official functions about the map type?
Thanks.
2011/5/24 Daniel Dai <[email protected]>
I cannot think of a way without writing UDF. You can write two UDF:
* GetKey, input a map, output the key of the map
* GetValues, input a bag of map, output a bag of map values
The script is like:
b = foreach ruls generate com.company.pig.GetURLContent($0,3,0.1)
as m;
c = foreach b generate GetKey(m) as key, m;
d = group c by key;
e = foreach c generate group, SUM(GetValues(c.m));
Daniel
On 05/23/2011 07:06 AM, Jameson Li wrote:
Hi all,
I have the below pig code:
register /home/uu/project/lib/pigudfs.jar
ruls = load 'testurl' as (url:chararray);
b = foreach ruls generate com.company.pig.GetURLContent($0,3,0.1);
here when dump b, it will return:
([4#0.1677963])
([193#0.16985779,81#0.10994483])
([418#0.14138427,9#0.1107544,282#0.18699136])
I just want group by the map key and sum the map value just like:
c = group b by $0#key;
d = foreach c generate group,SUM(b.$0#value);
How could I write the code?
Thanks,
Jameson Li.
