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From Joel Bernstein <joels...@gmail.com>
Subject Re: Joining more than 2 collections
Date Wed, 03 May 2017 12:59:17 GMT
Sorry, it's just called hashJoin

Joel Bernstein
http://joelsolr.blogspot.com/

On Wed, May 3, 2017 at 2:45 AM, Zheng Lin Edwin Yeo <edwinyeozl@gmail.com>
wrote:

> Hi Joel,
>
> I am getting this error when I used the innerHashJoin.
>
>  "EXCEPTION":"Invalid stream expression innerHashJoin(parallel(innerJoin
>
> I also can't find the documentation on innerHashJoin for the Streaming
> Expressions.
>
> Are you referring to hashJoin?
>
> Regards,
> Edwin
>
>
> On 3 May 2017 at 13:20, Zheng Lin Edwin Yeo <edwinyeozl@gmail.com> wrote:
>
> > Hi Joel,
> >
> > Thanks for the info.
> >
> > Regards,
> > Edwin
> >
> >
> > On 3 May 2017 at 02:04, Joel Bernstein <joelsolr@gmail.com> wrote:
> >
> >> Also take a look at the documentation for the "fetch" streaming
> >> expression.
> >>
> >> Joel Bernstein
> >> http://joelsolr.blogspot.com/
> >>
> >> On Tue, May 2, 2017 at 2:03 PM, Joel Bernstein <joelsolr@gmail.com>
> >> wrote:
> >>
> >> > Yes you join more then one collection with Streaming Expressions. Here
> >> are
> >> > a few things to keep in mind.
> >> >
> >> > * You'll likely want to use the parallel function around the largest
> >> join.
> >> > You'll need to use the join keys as the partitionKeys.
> >> > * innerJoin: requires that the streams be sorted on the join keys.
> >> > * innerHashJoin: has no sorting requirement.
> >> >
> >> > So a strategy for a three collection join might look like this:
> >> >
> >> > innerHashJoin(parallel(innerJoin(bigStream, bigStream)),
> smallerStream)
> >> >
> >> > The largest join can be done in parallel using an innerJoin. You can
> >> then
> >> > wrap the stream coming out of the parallel function in an
> innerHashJoin
> >> to
> >> > join it to another stream.
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > Joel Bernstein
> >> > http://joelsolr.blogspot.com/
> >> >
> >> > On Mon, May 1, 2017 at 9:42 PM, Zheng Lin Edwin Yeo <
> >> edwinyeozl@gmail.com>
> >> > wrote:
> >> >
> >> >> Hi,
> >> >>
> >> >> Is it possible to join more than 2 collections using one of the
> >> streaming
> >> >> expressions (Eg: innerJoin)? If not, is there other ways we can do
> it?
> >> >>
> >> >> Currently, I may need to join 3 or 4 collections together, and to
> >> output
> >> >> selected fields from all these collections together.
> >> >>
> >> >> I'm using Solr 6.4.2.
> >> >>
> >> >> Regards,
> >> >> Edwin
> >> >>
> >> >
> >> >
> >>
> >
> >
>

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