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https://issues.apache.org/jira/browse/FLINK-6888?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jark Wu updated FLINK-6888:
---------------------------
Description:
Currently the {{ACC}} TypeInformation of
{{org.apache.flink.table.functions.AggregateFunction[T, ACC]}} is extracted
using {{TypeInformation.of(Class)}}. When {{ACC}} is a Scala case class or
tuple class, the TypeInformation will fall back to {{GenericType}} which result
in bad performance when state de/serialization.
I suggest to extract the ACC TypeInformation when called
{{TableEnvironment.registerFunction()}}.
Here is an example:
{code}
case class Accumulator(sum: Long, count: Long)
class MyAgg extends AggregateFunction[Long, Accumulator] {
//Overloaded accumulate method
def accumulate(acc: Accumulator, value: Long): Unit = {
}
override def createAccumulator(): Accumulator = Accumulator(0, 0)
override def getValue(accumulator: Accumulator): Long = 1
}
{code}
The {{Accumulator}} will be recognized as {{GenericType<Accumulator>}}.
was:
Currently the {{ACC}} TypeInformation of
{{org.apache.flink.table.functions.AggregateFunction[T, ACC]}} is extracted
using {{TypeInformation.of(Class)}}. When {{ACC}} is a Scala case class or
tuple class, the TypeInformation will fall back to {{GenericType}} which result
in bad performance when state de/serialization.
I suggest to extract the ACC TypeInformation when called
{{TableEnvironment.registerFunction()}}.
> Can not determine TypeInformation of ACC type of AggregateFunction when ACC
> is a Scala case/tuple class
> -------------------------------------------------------------------------------------------------------
>
> Key: FLINK-6888
> URL: https://issues.apache.org/jira/browse/FLINK-6888
> Project: Flink
> Issue Type: Bug
> Components: Table API & SQL
> Reporter: Jark Wu
> Assignee: Jark Wu
> Fix For: 1.4.0
>
>
> Currently the {{ACC}} TypeInformation of
> {{org.apache.flink.table.functions.AggregateFunction[T, ACC]}} is extracted
> using {{TypeInformation.of(Class)}}. When {{ACC}} is a Scala case class or
> tuple class, the TypeInformation will fall back to {{GenericType}} which
> result in bad performance when state de/serialization.
> I suggest to extract the ACC TypeInformation when called
> {{TableEnvironment.registerFunction()}}.
> Here is an example:
> {code}
> case class Accumulator(sum: Long, count: Long)
> class MyAgg extends AggregateFunction[Long, Accumulator] {
> //Overloaded accumulate method
> def accumulate(acc: Accumulator, value: Long): Unit = {
> }
> override def createAccumulator(): Accumulator = Accumulator(0, 0)
> override def getValue(accumulator: Accumulator): Long = 1
> }
> {code}
> The {{Accumulator}} will be recognized as {{GenericType<Accumulator>}}.
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