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From Julian Hyde <jul...@hydromatic.net>
Subject Re: JdbcSort not used in plan.
Date Wed, 11 Mar 2015 23:16:29 GMT
Everything I know I've already said in this thread.

On Wed, Mar 11, 2015 at 4:02 PM, Jiunn Jye Ng <jiunnjye@gmail.com> wrote:
> Hi
> Jira case 616 raised for this
> https://issues.apache.org/jira/browse/CALCITE-616
>
> Can you suggest if there are any workaround to force the JdbcSort into
> action ?
>
> Thank you.
>
> Rgds,
> jay
>
> On Thu, Mar 12, 2015 at 3:30 AM, Vladimir Sitnikov <
> sitnikov.vladimir@gmail.com> wrote:
>
>> >Every extra variable (e.g. column count) you add is a new
>> opportunity for something to go wrong.
>>
>> I see that, however you need something to make project that reduces
>> columns cheaper, don't you?
>> On the other hand, if you use (rows, cpu) costing tuple, what would
>> you consider cheaper (2 rows, 3 cpu) or (3 rows, 2 cpu)?
>> The easiest way to compare costs is to use "rows + X*cpu" formula,
>> that basically requires some coefficient.
>>
>> > query failed to use JdbcSort
>> Well, I just picked a first JdbcTest test that did instantiate JdbcSort.
>> Of course we need a separate issue for sorting (i.e. simplest case for it).
>>
>> Vladimir
>>

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