Oh, I get it.
Thank you very much.

Haochao Zhuang






------------------ ???????? ------------------
??????: "Haisheng Yuan"<[email protected]>;
????????: 2018??11??14??(??????) ????11:29
??????: "????"<[email protected]>;"dev"<[email protected]>;

????:  Re: ?????? count(distinct col) can't recognize distinct



The plan is correct for the following query:

select channel, count(distinct version) from daming group by channel
76:SolrAggregate(group=[{0}], EXPR$1=[COUNT($1)])
  74:SolrAggregate(group=[{4, 7}])
    0:SolrTableScan(table=[[test03.loc:2181/dmsolr, daming]])

It will first get group by channel and version, then group by channel. the 
count will be the number of distinct versions. It is an optimization for single 
aggregation with count distinct.


Thanks ~
Haisheng Yuan
------------------------------------------------------------------
????????????<[email protected]>
????????2018??11??14?? 11:20:41
????????dev<[email protected]>
?????????????? count(distinct col) can't recognize distinct

Maybe I need to show more detail about this.
I printed the explaination using `input.explain(pw)`.


select channel, count(distinct version), sum(amount) from daming group by 
channel
500:SolrAggregate(group=[{4}], EXPR$1=[COUNT(DISTINCT $7)], EXPR$2=[SUM($0)])
  0:SolrTableScan(table=[[test03.loc:2181/dmsolr, daming]])


select channel, count(distinct version) from daming group by channel
76:SolrAggregate(group=[{0}], EXPR$1=[COUNT($1)])
  74:SolrAggregate(group=[{4, 7}])
    0:SolrTableScan(table=[[test03.loc:2181/dmsolr, daming]])



Thanks!


Best Regards
haochao.zhuang


------------------ ???????? ------------------
??????: "????"<[email protected]>;
????????: 2018??11??13??(??????) ????10:43
??????: "dev"<[email protected]>;

????: ?????? count(distinct col) can't recognize distinct







Dears


i catch it in the solr adaptor. it is implemented by solr as elasticsearch 
adaptor.


case a: correct
select a, count(distinct b) from tbl group by a;  


case b: incorrect
1. select a, count(distinct b) from tbl where c = 'c' group by a;

2. select a, count(distinct b), max(c)  from tbl group by a; 




attached solr's code


public void implement(Implementor implementor) {
    implementor.visitChild(0, getInput());


    final List<String> inNames = 
SolrRules.solrFieldNames(getInput().getRowType());
    for(Pair<AggregateCall, String> namedAggCall : getNamedAggCalls()) {


      AggregateCall aggCall = namedAggCall.getKey();


      Pair<String, String> metric = toSolrMetric(implementor, aggCall, inNames);
      implementor.addReverseAggMapping(namedAggCall.getValue(), 
metric.getKey().toLowerCase(Locale.ROOT)+"("+metric.getValue()+")");
      implementor.addMetricPair(namedAggCall.getValue(), metric.getKey(), 
metric.getValue());
    }
    ...
}


Best Regards
Haochao Zhuang






------------------ ???????? ------------------
??????: "Michael Mior"<[email protected]>;
????????: 2018??11??13??(??????) ????9:35
??????: "dev"<[email protected]>;

????: Re: count(distinct col) can't recognize distinct



Can you give a specific example of a query that doesn't do what you expect
it to do?

--
Michael Mior
[email protected]


Le mar. 13 nov. 2018 ?? 07:56, ???? <[email protected]> a ??crit :

> Hi Guys:
>
>
> I got a question why it can't recognize DISTINCT tag on COUNT(DISTINCT
> col) aggregation function sometimes.
>
>
> but it is not problem when my sql query statement have WHEN clause or one
> more aggregation functions.
>
>
> Best Regards
> Haochao Zhuang

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