If you JUST want a1, then you would do A = LOAD 'data' AS (a1:int,a2:int,a3:int); B = DISTINCT (foreach A generate a1);
basically you project the column you want, and distinct on it. 2012/6/26 Haitao Yao <yao.e...@gmail.com> > I want a subset of A with a1 value distinct. > the current distinct will compare all the fields in A, which is not what I > want. > > > > Haitao Yao > yao.e...@gmail.com > weibo: @haitao_yao > Skype: haitao.yao.final > > 在 2012-6-27，上午11:18， Jonathan Coveney 写道： > > > What is your desired output? Sounds like you want a group. > > > > 2012/6/26 Haitao Yao <yao.e...@gmail.com> > > > >> hi, > >> How can I distinct only one field of a relation? > >> here's the demo: > >> > >> A = LOAD 'data' AS (a1:int,a2:int,a3:int); > >> B = distinct A by a1; > >> > >> > >> how can I do this? > >> > >> > >> > >> Haitao Yao > >> yao.e...@gmail.com > >> weibo: @haitao_yao > >> Skype: haitao.yao.final > >> > >> > >
