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From Sean Huo <s...@crunchyroll.com>
Subject Re: counting returns different results
Date Tue, 10 Jun 2014 21:43:44 GMT
The two queries seems to yield the same results for relatively small query
size, but diverge when the query size is really big (30*70 millions rows)


On Tue, Jun 10, 2014 at 2:07 PM, Gabriel Reid <gabriel.reid@gmail.com>
wrote:

> Hi Sean,
>
> That doesn't sound right -- any idea which of the queries (if either)
> is returning the correct results?
>
> Any chance you could try this out on a small test table and then post
> the relevant DDL and literal queries here?
>
> - Gabriel
>
>
> On Tue, Jun 10, 2014 at 10:30 PM, Sean Huo <sean@crunchyroll.com> wrote:
> > These two queries returns vastly different results:
> >
> > query1:
> > select count(1) from t where date > 'certain day' and device ='A';
> >
> > query2:
> >
> > select device, count(1) from t where date >'certain day' and device ='A'
> > group by device;
> >
> > assuming table t has the  composite primary key of
> > date timestamp, and device varchar.
> >
> > What gives?
> >
>

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