AFAIK functions (scalar in particular) are generated.
On Jul 16, 2016 00:19, "Vignesh Raghunathan" <
[email protected]> wrote:
> Hi,
>
> I am trying to step through some of the function descriptor code. For
> instance, I launched an AsterixDB instance via
> AsterixHyracksIntegrationUtil, placed a breakpoint in
>
> org.apache.asterix.runtime.evaluators.constructors.ATimeConstructorDescriptor.createEvaluatorFactory(...).new
> IScalarEvaluatorFactory() {...}.createScalarEvaluator(...).new
> IScalarEvaluator() {...}.evaluate(IFrameTupleReference, IPointable)
>
> and ran the query
>
> let $v := time(“12:23:23”)
> return $v
>
> However, execution doesn’t stop at the breakpoint. My questions are as
> follows:
>
> 1. http://sigmod.github.io/papers/socc15-final153.pdf <
> http://sigmod.github.io/papers/socc15-final153.pdf> mentions runtime
> artifacts called evaluators for function expressions. Is the evaluate
> function mentioned above part of an evaluator for the time constructor?
>
> 2. Is a separate JVM launched for each virtual node controller?
>
> 3. How can I debug a task that is scheduled to run in a particular node
> controller?
>
> As an aside, http://sigmod.github.io/papers/socc15-final153.pdf <
> http://sigmod.github.io/papers/socc15-final153.pdf> mentions that
> translation between logical functions and evaluators happen during the job
> generation phase. Does that mean the rule based physical optimization phase
> is skipped for functions?
>
> I am also not able to figure out where the function evaluators are
> actually called in code. Where can I find them?
>
> Thanks,
> Vignesh
>
>
> > On Jul 7, 2016, at 2:23 AM, Mike Carey <[email protected]> wrote:
> >
> > Vignesh,
> >
> > Count would actually be a particularly bad example to start with. :-)
> Aggregate functions (count, min, max, sum, avg) are not like other
> functions - they are special and more complicated / very different.
> Instead, you should look at simple(r) functions like almost anything else
> described at
> https://asterixdb.apache.org/docs/0.8.8-incubating/aql/functions.html.
> >
> >
> > Cheers,
> >
> > Mike
> >
> > On 7/6/16 11:29 AM, Xikui Wang wrote:
> >> Hi Vignesh,
> >>
> >> There is an entrance class called: AsterixHyracksIntegrationUtil. You
> can
> >> find it under: org.apache.asterix.api.common. The main method in this
> class
> >> enables you to launch a local instance for debugging. From my own
> >> experience, QueryTranslator will be a good start point to trace the
> process.
> >>
> >> Best,
> >> Xikui
> >>
> >> On Wed, Jul 6, 2016 at 11:16 AM, Vignesh Raghunathan <
> >> [email protected]> wrote:
> >>
> >>> Hi,
> >>>
> >>> I've been trying to figure out how functions are implemented under the
> hood
> >>> in AsterixDB. For example, I would like to know what happens when the
> aql
> >>> statement count([1,2,3]) is executed.
> >>>
> >>> I tried to set up remote debugging in eclipse to step through the code.
> >>> However, I'm not sure what to change to launch an asterixdb instance in
> >>> debug mode. Is there a way to do it?
> >>>
> >>> Thanks,
> >>> Vignesh
> >>>
> >
>
>
