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Posted to dev@drill.apache.org by Ted Dunning <te...@gmail.com> on 2015/04/09 03:20:36 UTC
limit and count do odd things
Am I missing something? It seems that count should return 3 in the second
query.
This happens with the 0.8.0 release running in embedded mode.
0: jdbc:drill:zk=local> select count(1) from
dfs.`/Users/tdunning/tmp/apache-drill-0.8.0/foo/*`;
+------------+
| EXPR$0 |
+------------+
| 20000 |
+------------+
1 row selected (1.311 seconds)
0: jdbc:drill:zk=local> select count(*) from
dfs.`/Users/tdunning/tmp/apache-drill-0.8.0/foo/*` limit 3;
+------------+
| EXPR$0 |
+------------+
| 20000 |
+------------+
Re: limit and count do odd things
Posted by Ted Dunning <te...@gmail.com>.
On Thu, Apr 9, 2015 at 12:25 AM, Julian Hyde <ju...@gmail.com> wrote:
> 'll forgive you (and anyone) the occasional intellectual lapse. I came
> across your wonderful t-digest paper earlier today.
>
Well, there is another example. But thanks to my new co-author, that paper
is getting significantly better in the near future.
Re: limit and count do odd things
Posted by Julian Hyde <ju...@gmail.com>.
Ted,
I'll forgive you (and anyone) the occasional intellectual lapse. I came across your wonderful t-digest paper earlier today.
https://github.com/tdunning/t-digest/raw/master/docs/t-digest-paper/histo.pdf
Julian
> On Apr 8, 2015, at 20:20, Ted Dunning <te...@gmail.com> wrote:
>
> Thanks.
>
> Brain fart.
>
>> On Wed, Apr 8, 2015 at 8:26 PM, Aman Sinha <as...@maprtech.com> wrote:
>>
>> Why ? limit is applied to the final result set of the query. If you did
>> select count(*) from (select * from T limit 3) you will get 3.
>>
>>> On Wed, Apr 8, 2015 at 6:20 PM, Ted Dunning <te...@gmail.com> wrote:
>>>
>>> Am I missing something? It seems that count should return 3 in the
>> second
>>> query.
>>>
>>> This happens with the 0.8.0 release running in embedded mode.
>>>
>>>
>>> 0: jdbc:drill:zk=local> select count(1) from
>>> dfs.`/Users/tdunning/tmp/apache-drill-0.8.0/foo/*`;
>>> +------------+
>>> | EXPR$0 |
>>> +------------+
>>> | 20000 |
>>> +------------+
>>> 1 row selected (1.311 seconds)
>>> 0: jdbc:drill:zk=local> select count(*) from
>>> dfs.`/Users/tdunning/tmp/apache-drill-0.8.0/foo/*` limit 3;
>>> +------------+
>>> | EXPR$0 |
>>> +------------+
>>> | 20000 |
>>> +------------+
>>
Re: limit and count do odd things
Posted by Ted Dunning <te...@gmail.com>.
Thanks.
Brain fart.
On Wed, Apr 8, 2015 at 8:26 PM, Aman Sinha <as...@maprtech.com> wrote:
> Why ? limit is applied to the final result set of the query. If you did
> select count(*) from (select * from T limit 3) you will get 3.
>
> On Wed, Apr 8, 2015 at 6:20 PM, Ted Dunning <te...@gmail.com> wrote:
>
> > Am I missing something? It seems that count should return 3 in the
> second
> > query.
> >
> > This happens with the 0.8.0 release running in embedded mode.
> >
> >
> > 0: jdbc:drill:zk=local> select count(1) from
> > dfs.`/Users/tdunning/tmp/apache-drill-0.8.0/foo/*`;
> > +------------+
> > | EXPR$0 |
> > +------------+
> > | 20000 |
> > +------------+
> > 1 row selected (1.311 seconds)
> > 0: jdbc:drill:zk=local> select count(*) from
> > dfs.`/Users/tdunning/tmp/apache-drill-0.8.0/foo/*` limit 3;
> > +------------+
> > | EXPR$0 |
> > +------------+
> > | 20000 |
> > +------------+
> >
>
Re: limit and count do odd things
Posted by Aman Sinha <as...@maprtech.com>.
Why ? limit is applied to the final result set of the query. If you did
select count(*) from (select * from T limit 3) you will get 3.
On Wed, Apr 8, 2015 at 6:20 PM, Ted Dunning <te...@gmail.com> wrote:
> Am I missing something? It seems that count should return 3 in the second
> query.
>
> This happens with the 0.8.0 release running in embedded mode.
>
>
> 0: jdbc:drill:zk=local> select count(1) from
> dfs.`/Users/tdunning/tmp/apache-drill-0.8.0/foo/*`;
> +------------+
> | EXPR$0 |
> +------------+
> | 20000 |
> +------------+
> 1 row selected (1.311 seconds)
> 0: jdbc:drill:zk=local> select count(*) from
> dfs.`/Users/tdunning/tmp/apache-drill-0.8.0/foo/*` limit 3;
> +------------+
> | EXPR$0 |
> +------------+
> | 20000 |
> +------------+
>