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From Denis Magda <dma...@apache.org>
Subject Re: SQLQuery with simple Join return no results
Date Fri, 01 Sep 2017 22:07:29 GMT
If you use Strings as the keys you won’t get affinity collocation set up properly and distributed
joins will return an incomplete result. One of the keys have to comprise a “parent” class
key that will be an affinity key. Look at the example here:
https://apacheignite.readme.io/docs/affinity-collocation#section-collocate-data-with-data
<https://apacheignite.readme.io/docs/affinity-collocation#section-collocate-data-with-data>

As for the NON collocated joins suggested by Roger (qry.setDistributedJoins( true)), I would
use them only if it’s impossible to set up the collocation between 2 entities. That’s
not your case from what I see. NON collocated joins are slower than collocated ones.

—
Denis


> On Sep 1, 2017, at 2:53 PM, Roger Fischer (CW) <rfische@Brocade.com> wrote:
> 
> Hi Matt,
> 
> are the objects to join collocated, ie. do they have the same affinity key? If yes, it
should work (it worked for me).
> 
> If no, you need to enable distributed joins for the query. See the middle line.
> 
>            SqlFieldsQuery qry = new SqlFieldsQuery( stmt);
>            qry.setDistributedJoins( true);
>            queryCursor = aCache.query( qry);
> 
> Roger
> 
> -----Original Message-----
> From: matt [mailto:goodieboy@gmail.com <mailto:goodieboy@gmail.com>] 
> Sent: Friday, September 01, 2017 1:52 PM
> To: user@ignite.apache.org <mailto:user@ignite.apache.org>
> Subject: SQLQuery with simple Join return no results
> 
> I have 2 caches defined, both with String keys, and classes that make use of the Ignite
annotations for indexes and affinity. I've got 3 different nodes running, and the code I'm
using to populate the cache w/test data works, and I can see each node is updated with its
share of the data. My index types are set on the caches as well.
> 
> If I do a ScanQuery, I can see that all of the fields and IDs are correct, Ignite returns
them all. But when doing a SqlQuery, I get nothing back.
> Ignite is not complaining about the query, it's just returning an empty cursor.
> 
> If I remove the Join, results are returned.
> 
> So I'm wondering if this is related to the way I've set up my affinity mapping. It's
basically setup like the code below... and the query looks like this:
> 
> "from B, A WHERE B.id = A.bID"
> 
> Any ideas on what I'm doing wrong here?
> 
> class A implements Serializable {
>  @QuerySqlField(index = true)
>  String id;
> 
>  @QuerySqlField(index = true)
>  String bId;  
> 
>  @AffinityKeyMapped
>  @QuerySqlField(index = true)
>  String group;
> }
> 
> class B implements Serializable {
>  @QuerySqlField(index = true)
>  String id;
> 
>  @AffinityKeyMapped
>  @QuerySqlField(index = true)
>  String group;
> }
> 
> 
> 
> --
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