Mugeesh,
You can use Streaming Aggregation to provide various types of
cross-collection joins. This is currently available in trunk and will be a
part of Solr 6.
To follow with your example, let's assume the following setup:
Restaurants: avail on machine1:8983 with 3 shards, zk at zk1:2345
Users: avail on machine2:8983 with 2 shards, zk at zk2:2345
Reviews: avail on machine1:8983 with 10 shards, zk at zk1:2345
You could send a streaming query to solr that would return all reviews for
restaurants in NYC and include the user's hometown
hashJoin(
innerJoin(
search(users, q="*:*", fl="userId, full_name, hometown", sort="userId
asc", zkHost="zk2:2345", qt="/export"),
search(reviews, q="*:*", fl="userId, review, score", sort="userId asc",
zkHost="zk1:2345", qt="/export"),
on="userId"
),
hashed=search(restaurants, q="city:nyc", fl="restaurantId,
restaurantName", sort="restaurantId asc", zkHost="zk1:2345", qt="/export"),
on="restaurantId"
)
Note that the # of shards doesn't matter and doesn't need to be considered
as a part of your query. Were you to send this off to a url for result,
it'd look like this
http://machine1:8983/solr/users/stream?stream=
<http://localhost:8983/solr/careers/stream?stream=innerJoin(search(careers>[the
expression above]
Additional information about Streaming API, Streaming Aggregation, and
Streaming Expressions can be found at
https://cwiki.apache.org/confluence/display/solr/Streaming+Expressions,
though this is currently incomplete as a lot of the new features have yet
to be added to the documentation.
For those interested, joins were added under tickets
https://issues.apache.org/jira/browse/SOLR-7584 and
https://issues.apache.org/jira/browse/SOLR-8188.
- Dennis
On Mon, Dec 7, 2015 at 7:42 AM, Mugeesh Husain <muge...@gmail.com> wrote:
> I have create 3 cores on same machine using solrlcoud.
> core: Restaurant,User,Review
> each of core has only 1 shards and 2 replicas.
>
> Question
> 1.) It is possible to use join among 3 of cores on same machine( or
> different machine)
> 2.)I am struggling how to use join among 3 of core in solrlcoud mode.
>
> Client: is not interested to de-normalized data.
>
> Give some suggestion how to solved that problem.
>
> Thanks
> Mugeesh
>
>
>
> --
> View this message in context:
> http://lucene.472066.n3.nabble.com/Joins-with-SolrCloud-tp4243957.html
> Sent from the Solr - User mailing list archive at Nabble.com.
>
