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https://issues.apache.org/jira/browse/FLINK-3474?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15179698#comment-15179698
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ASF GitHub Bot commented on FLINK-3474:
---------------------------------------
Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/1746#discussion_r55014256
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/api/table/runtime/aggregate/AvgAggregate.scala
---
@@ -17,115 +17,144 @@
*/
package org.apache.flink.api.table.runtime.aggregate
-import java.math.BigInteger
import com.google.common.math.LongMath
+import org.apache.calcite.sql.`type`.SqlTypeName
+import org.apache.flink.api.table.Row
-// for byte, short, int we return int
-abstract class IntegralAvgAggregate[T: Numeric] extends Aggregate[T] {
+abstract class IntegralAvgAggregate[T] extends Aggregate[T] {
+ private final val intermediateType = Array(SqlTypeName.BIGINT,
SqlTypeName.BIGINT)
- var sum: Long = 0
- var count: Long = 0
+ override def initiate(partial: Row): Unit = {
+ partial.setField(aggOffsetInRow, 0L)
+ partial.setField(aggOffsetInRow + 1, 0L)
+ }
+
+ override def merge(partial: Row, buffer: Row): Unit = {
+ val partialSum =
partial.productElement(aggOffsetInRow).asInstanceOf[Long]
+ val partialCount = partial.productElement(aggOffsetInRow +
1).asInstanceOf[Long]
+ val bufferSum =
buffer.productElement(aggOffsetInRow).asInstanceOf[Long]
+ val bufferCount = buffer.productElement(aggOffsetInRow +
1).asInstanceOf[Long]
+ buffer.setField(aggOffsetInRow, LongMath.checkedAdd(partialSum,
bufferSum))
+ buffer.setField(aggOffsetInRow + 1, LongMath.checkedAdd(partialCount,
bufferCount))
+ }
- override def initiateAggregate: Unit = {
- sum = 0
- count = 0
+ override def intermediateDataType: Array[SqlTypeName] = {
+ intermediateType
}
+ override def supportPartial: Boolean = true
}
class ByteAvgAggregate extends IntegralAvgAggregate[Byte] {
-
- override def aggregate(value: Any): Unit = {
- count += 1
- sum = LongMath.checkedAdd(sum, value.asInstanceOf[Byte])
+ override def prepare(value: Any, partial: Row): Unit = {
+ val input = value.asInstanceOf[Byte]
+ partial.setField(aggOffsetInRow, input.toLong)
+ partial.setField(aggOffsetInRow + 1, 1L)
}
- override def getAggregated(): Byte = {
- (sum / count).toByte
+ override def evaluate(buffer: Row): Byte = {
+ val bufferSum =
buffer.productElement(aggOffsetInRow).asInstanceOf[Long]
+ val bufferCount = buffer.productElement(aggOffsetInRow +
1).asInstanceOf[Long]
+ (bufferSum / bufferCount).toByte
}
}
class ShortAvgAggregate extends IntegralAvgAggregate[Short] {
- override def aggregate(value: Any): Unit = {
- count += 1
- sum = LongMath.checkedAdd(sum, value.asInstanceOf[Short])
+ override def prepare(value: Any, partial: Row): Unit = {
+ val input = value.asInstanceOf[Short]
+ partial.setField(aggOffsetInRow, input.toLong)
+ partial.setField(aggOffsetInRow + 1, 1L)
}
- override def getAggregated(): Short = {
- (sum / count).toShort
+ override def evaluate(buffer: Row): Short = {
+ val bufferSum =
buffer.productElement(aggOffsetInRow).asInstanceOf[Long]
+ val bufferCount = buffer.productElement(aggOffsetInRow +
1).asInstanceOf[Long]
+ (bufferSum / bufferCount).toShort
}
}
class IntAvgAggregate extends IntegralAvgAggregate[Int] {
- override def aggregate(value: Any): Unit = {
- count += 1
- sum = LongMath.checkedAdd(sum, value.asInstanceOf[Int])
+ override def prepare(value: Any, partial: Row): Unit = {
+ val input = value.asInstanceOf[Int]
+ partial.setField(aggOffsetInRow, input.toLong)
--- End diff --
The previous version used a `BigInteger` to compute the sum of a `Long`
average. Can you change it back or explain why you would like to change that?
> Partial aggregate interface design and sort-based implementation
> ----------------------------------------------------------------
>
> Key: FLINK-3474
> URL: https://issues.apache.org/jira/browse/FLINK-3474
> Project: Flink
> Issue Type: Sub-task
> Components: Table API
> Reporter: Chengxiang Li
> Assignee: Chengxiang Li
>
> The scope of this sub task includes:
> # Partial aggregate interface.
> # Simple aggregate function implementation, such as SUM/AVG/COUNT/MIN/MAX.
> # DataSetAggregateRule which translate logical calcite aggregate node to
> Flink user functions. As hash-based combiner is not available yet(see PR
> #1517), we would use sort-based combine as default.
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