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
>>>
>
