Hi,
I had come across the reduce function in the docs but
I have a hard time getting it to work; I haven't found any documentation on it
or its parameters, and the source code of the GroupOperation doesn't explain it
either ...
For example, what is the "n" parameter about?
I constructed a source stream to produce the input from my second example:
merge(
sort(cartesianProduct(tuple(k1="1", k2=array(a)), k2, productSort="k1
asc"), by="k1 asc"),
sort(cartesianProduct(tuple(k1="2", k2=array(b,c)), k2, productSort="k1
asc"), by="k1 asc"),
on="k1 asc"
)
--->
{
"result-set": {
"docs": [
{
"k1": "1",
"k2": "a"
},
{
"k1": "2",
"k2": "b"
},
{
"k1": "2",
"k2": "c"
},
{
"EOF": true,
"RESPONSE_TIME": 0
}
]
}
}
Then wrapped in a reduce function:
reduce(
merge(
sort(cartesianProduct(tuple(k1="1", k2=array(a)), k2, productSort="k1
asc"), by="k1 asc"),
sort(cartesianProduct(tuple(k1="2", k2=array(b,c)), k2, productSort="k1
asc"), by="k1 asc"),
on="k1 asc"
),
by="k1",
group(sort="k1 asc", n="10")
)
--->
{
"result-set": {
"docs": [
{
"k1": "1",
"k2": "a",
"group": [
{
"k1": "1",
"k2": "a"
}
]
},
{
"k1": "2",
"k2": "c",
"group": [
{
"k1": "2",
"k2": "c"
},
{
"k1": "2",
"k2": "b"
}
]
},
{
"EOF": true,
"RESPONSE_TIME": 0
}
]
}
}
It adds a field "group" that contains an array of the unchanged input documents
with the same "by" value,
not grouped values.
{
"result-set": {
"docs": [
{
"k1": "1",
"k2": "a",
"group": [
{
"k1": "1",
"k2": "a"
}
]
},
{
"k1": "2",
"k2": "c",
"group": [
{
"k1": "2",
"k2": "c"
},
{
"k1": "2",
"k2": "b"
}
]
},
{
"EOF": true,
"RESPONSE_TIME": 0
}
]
}
}
Or am I doing it wrong?
Christian Spitzlay
> Am 15.06.2018 um 01:48 schrieb Joel Bernstein <joels...@gmail.com>:
>
> Actually you're second example is probably a straight forward:
>
> reduce(select(...), group(...), by="k1")
>
> Joel Bernstein
> http://joelsolr.blogspot.com/
>
> On Thu, Jun 14, 2018 at 7:33 PM, Joel Bernstein <joels...@gmail.com> wrote:
>
>> Take a look at the reduce() function. You'll have to write a custom reduce
>> operation but you can follow the example here:
>>
>> https://github.com/apache/lucene-solr/blob/master/solr/
>> solrj/src/java/org/apache/solr/client/solrj/io/ops/GroupOperation.java
>>
>> You can plug in your custom reduce operation in the solrconfig.xml and use
>> it like any other function. If you're interested in working on this you
>> could create a ticket and I can provide guidance.
>>
>>
>> Joel Bernstein
>> http://joelsolr.blogspot.com/
>>
>> 2018-06-14 13:13 GMT-04:00 Christian Spitzlay <
>> christian.spitz...@biologis.com>:
>>
>>> Hi,
>>>
>>> is there a way to merge array values?
>>>
>>> Something that transforms
>>>
>>> {
>>> "k1": "1",
>>> "k2": ["a", "b"]
>>> },
>>> {
>>> "k1": "2",
>>> "k2": ["c", "d"]
>>> },
>>> {
>>> "k1": "2",
>>> "k2": ["e", "f"]
>>> }
>>>
>>> into
>>>
>>> {
>>> "k1": "1",
>>> "k2": ["a", "b"]
>>> },
>>> {
>>> "k1": "2",
>>> "k2": ["c", "d", "e", "f"]
>>> }
>>>
>>>
>>> And an inverse of cartesianProduct() that transforms
>>>
>>> {
>>> "k1": "1",
>>> "k2": "a"
>>> },
>>> {
>>> "k1": "2",
>>> "k2": "b"
>>> },
>>> {
>>> "k1": "2",
>>> "k2": "c"
>>> }
>>>
>>> into
>>>
>>> {
>>> "k1": "1",
>>> "k2": ["a"]
>>> },
>>> {
>>> "k1": "2",
>>> "k2": ["b", "c"]
>>> }
>>>
>>>
>>> Christian
>>>
>>>
>>>
>>
