In this case iam thinking as giving input to the map class as one table and
using hbase API to extract rows in other table ... but i have one doubt in
this ...
Can a single Map instance emit more than 1 (Key,value) pairs ?
Is the following situation feasible (Inputs to the map are table1 rowkey
and rowresult and i use API to scan table2 and emit table2 rowkeys and
rowresults)
If that works i think we must ensure that the looping takes place for only
one value of table1_rowkey..
*********EXAMPLE**********************
Map(table1_rowkey , table1_rowresult )
{
loop(table2)
{
emit(table2_rowkey,table2_rowresult)
}
emit(table1_rowkey,table1_rowresult)
}
************END******************************
On Wed, Jul 22, 2009 at 8:50 AM, stack <[email protected]> wrote:
> In the past, not knowing any better, I've made dummy imputs. Make a file
> of
> as many lines as you'd like mappers, use TextInputFormat and just ignore
> the
> input or trigger what the particular mapper does off passed input.
>
> St.Ack
>
>
> On Tue, Jul 21, 2009 at 8:13 PM, bharath vissapragada <
> [email protected]> wrote:
>
> > By saying "using API in your job to pull from multiple table" do you mean
> > that in the Map phase itself we use HBase API to fetch table rows ? If
> yes
> > then what should we give as input to the map function , can we leave it
> as
> > a
> > blank?
> >
> > On Wed, Jul 22, 2009 at 12:43 AM, Jonathan Gray <[email protected]>
> wrote:
> >
> > > Currently, there is not.
> > >
> > > You would have multiple MR jobs, or you would directly use the API in
> > your
> > > job to pull from multiple tables.
> > >
> > > I suppose it would be feasible, but as it is now, you are not told
> which
> > > table your Result comes from.
> > >
> > >
> > > bharath vissapragada wrote:
> > >
> > >> Hi all,
> > >>
> > >>
> > >> Generally TableMap.initJob() method takes a "table name" as input
> to
> > >> the
> > >> map while using map-reduce in HBase .
> > >>
> > >> Is there a way so that i can use more than 1 table , i.e., input to
> the
> > >> map
> > >> contains more than 1 table ,
> > >>
> > >> Thanks
> > >>
> > >>
> >
>
