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[SPARK-15764][SQL] Replace N^2 loop in BindReferences #13505

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[SPARK-15764][SQL] Replace N^2 loop in BindReferences #13505

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6216e94
Replace N^2 loop in BindReferences.
JoshRosen Jun 4, 2016
b1a7646
Fix Java 7 compilation issue.
JoshRosen Jun 4, 2016
38e8a99
Whoops, getOrDefault is also new in Java 8.
JoshRosen Jun 4, 2016
0b412b0
Amortize map construction.
JoshRosen Jun 4, 2016
bc17587
Merge remote-tracking branch 'origin/master' into bind-references-imp…
JoshRosen Jun 4, 2016
e7c4150
Fix similar loop in InMemoryTableScanExec.
JoshRosen Jun 4, 2016
210dbd3
Rename getOrdinal to getOrdinalWithExprId
JoshRosen Jun 4, 2016
dd94e29
Delete some related yet dead code in AttributeMap.
JoshRosen Jun 4, 2016
b933fe0
Code style and readability improvements.
JoshRosen Jun 4, 2016
4efd3ee
Comments.
JoshRosen Jun 4, 2016
5504b6c
Address Eric's comments.
JoshRosen Jun 5, 2016
bdb68ad
Merge remote-tracking branch 'origin/master' into bind-references-imp…
JoshRosen Jun 6, 2016
99197b7
Add missing `@transient` annotations.
JoshRosen Jun 6, 2016
5e9c258
Also extend Serializable.
JoshRosen Jun 6, 2016
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Code style and readability improvements.
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@JoshRosen
JoshRosen committed Jun 4, 2016
commit b933fe08e61b529e77c0923d5b559102463a1ff4
16 changes: 10 additions & 6 deletions sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/package.scala
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Expand Up @@ -17,6 +17,8 @@

package org.apache.spark.sql.catalyst

import com.google.common.collect.Maps

import org.apache.spark.sql.catalyst.expressions._
import org.apache.spark.sql.types.{StructField, StructType}

Expand Down Expand Up @@ -94,12 +96,14 @@ package object expressions {

private lazy val inputArr = attrs.toArray

private lazy val inputToOrdinal = {
val map = new java.util.HashMap[ExprId, Int](inputArr.length * 2)
private lazy val exprIdToOrdinal = {
val arr = inputArr
val map = Maps.newHashMapWithExpectedSize[ExprId, Int](arr.length)
var index = 0
attrs.foreach { attr =>
if (!map.containsKey(attr.exprId)) {
map.put(attr.exprId, index)
while (index < arr.length) {
val exprId = arr(index).exprId
if (!map.containsKey(exprId)) {
map.put(exprId, index)
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@ericl ericl Jun 5, 2016

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Is it necessary to check containsKey before the put?

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@JoshRosen JoshRosen Jun 5, 2016 •
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I was being conservative here in order to match the behavior of the old linear scan, which stopped upon finding the first entry with a matching expression id. However, we can remove the need for this check if we iterate over arr in reverse-order.

}
index += 1
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@kiszk kiszk Jun 4, 2016

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Which style is better, this style or a style to use zipWithIndex?

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@JoshRosen JoshRosen Jun 4, 2016

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This was just a minor perf. optimization since this method was in a hot path.

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@JoshRosen JoshRosen Jun 4, 2016

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On the other hand, accessing a variable that's outside of the inner closure is likely to be expensive, too. It's probably fastest to just iterate over the elements of inputArr.

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@kiszk kiszk Jun 5, 2016

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Got it. I did not have no preference. Good to hear a reason for this decision.

}
Expand All @@ -109,7 +113,7 @@ package object expressions {
def apply(ordinal: Int): Attribute = inputArr(ordinal)

def getOrdinalWithExprId(exprId: ExprId): Int = {
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@ericl ericl Jun 5, 2016

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Would indexOf be more clear?

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@JoshRosen JoshRosen Jun 5, 2016

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I had this originally and then moved to this name in anticipation of a future change which would add more "get index with property" methods, but a lot of those methods aren't cachable (e.g. semanticEquals), so I'll revert this back to my first name choice.

Option(inputToOrdinal.get(exprId)).getOrElse(-1)
Option(exprIdToOrdinal.get(exprId)).getOrElse(-1)
}
}

Expand Down