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Implement RANGE bounded window frame #561

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Implement RANGE bounded window frame #561

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5ec243c
Implement RANGE bounded PRECEDING window frame
Jun 2, 2017
671c16d
Implement RANGE bounded FOLLOWING window frame
Jun 6, 2017
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77 changes: 71 additions & 6 deletions presto-main/src/main/java/com/facebook/presto/operator/window/WindowPartition.java
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,7 @@
import com.facebook.presto.sql.tree.FrameBound;
import com.google.common.collect.ImmutableList;

import java.util.ArrayList;
import java.util.List;

import static com.facebook.presto.spi.StandardErrorCode.INVALID_WINDOW_FRAME;
Expand All @@ -28,6 +29,7 @@
import static com.facebook.presto.sql.tree.FrameBound.Type.UNBOUNDED_FOLLOWING;
import static com.facebook.presto.sql.tree.FrameBound.Type.UNBOUNDED_PRECEDING;
import static com.facebook.presto.sql.tree.WindowFrame.Type.RANGE;
import static com.facebook.presto.sql.tree.WindowFrame.Type.ROWS;
import static com.facebook.presto.util.Failures.checkCondition;
import static com.google.common.base.Preconditions.checkState;
import static java.lang.Math.toIntExact;
Expand All @@ -46,6 +48,8 @@ public final class WindowPartition
private int peerGroupEnd;

private int currentPosition;
private List<Integer> peerGroupStartIndices = new ArrayList<>();
private List<Integer> peerGroupEndIndices = new ArrayList<>();

public WindowPartition(PagesIndex pagesIndex,
int partitionStart,
Expand Down Expand Up @@ -142,6 +146,8 @@ private void updatePeerGroup()
while ((peerGroupEnd < partitionEnd) && pagesIndex.positionEqualsPosition(peerGroupHashStrategy, peerGroupStart, peerGroupEnd)) {
peerGroupEnd++;
}
peerGroupStartIndices.add(peerGroupStart);
peerGroupEndIndices.add(peerGroupEnd);
}

private Range getFrameRange(FrameInfo frameInfo)
Expand All @@ -150,7 +156,11 @@ private Range getFrameRange(FrameInfo frameInfo)
int endPosition = partitionEnd - partitionStart - 1;

// handle empty frame
if (emptyFrame(frameInfo, rowPosition, endPosition)) {
if (frameInfo.getType() == ROWS && emptyFrame(frameInfo, rowPosition, endPosition - rowPosition)) {
return new Range(-1, -1);
}

if (frameInfo.getType() == RANGE && emptyFrame(frameInfo, peerGroupStart, endPosition - (peerGroupEnd - 1))) {
return new Range(-1, -1);
}

Expand All @@ -161,6 +171,12 @@ private Range getFrameRange(FrameInfo frameInfo)
if (frameInfo.getStartType() == UNBOUNDED_PRECEDING) {
frameStart = 0;
}
else if (frameInfo.getType() == RANGE && frameInfo.getStartType() == PRECEDING) {
frameStart = precedingStartRange(getStartValue(frameInfo));
}
else if (frameInfo.getType() == RANGE && frameInfo.getStartType() == FOLLOWING) {
frameStart = followingRange(rowPosition, endPosition, getStartValue(frameInfo));
}
else if (frameInfo.getStartType() == PRECEDING) {
frameStart = preceding(rowPosition, getStartValue(frameInfo));
}
Expand All @@ -178,6 +194,12 @@ else if (frameInfo.getType() == RANGE) {
if (frameInfo.getEndType() == UNBOUNDED_FOLLOWING) {
frameEnd = endPosition;
}
else if (frameInfo.getType() == RANGE && frameInfo.getEndType() == PRECEDING) {
frameEnd = precedingEndRange(getEndValue(frameInfo));
}
else if (frameInfo.getType() == RANGE && frameInfo.getEndType() == FOLLOWING) {
frameEnd = followingRange(peerGroupEnd, endPosition + 1, getEndValue(frameInfo)) - 1;
}
else if (frameInfo.getEndType() == PRECEDING) {
frameEnd = preceding(rowPosition, getEndValue(frameInfo));
}
Expand All @@ -194,19 +216,62 @@ else if (frameInfo.getType() == RANGE) {
return new Range(frameStart, frameEnd);
}

private boolean emptyFrame(FrameInfo frameInfo, int rowPosition, int endPosition)
private int precedingEndRange(long endValue)
{
int peerGroupEndIndex = peerGroupEndIndices.indexOf(peerGroupEnd);
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I'd use Map<Integer, Integer> (peer group -> position) instead of ArrayList<Integer>, to avoid slowness when there are many tiny groups in a large partition.
Imagine billions of rows with ~1 row / peer group.
Then indexOf will be O(billions). But if you use a Map, it's gonna be O(log(billions)).

if (peerGroupEndIndex < endValue) {
return peerGroupEnd - 1;
}
return peerGroupEndIndices.get(toIntExact(peerGroupEndIndex - endValue)) - 1;
}

private int precedingStartRange(long startValue)
{
int peerGroupStartIndex = peerGroupStartIndices.indexOf(peerGroupStart);
if (peerGroupStartIndex < startValue) {
return 0;
}
return peerGroupStartIndices.get(toIntExact(peerGroupStartIndex - startValue));
}

private int followingRange(int followingPeerGroupStart, int endPosition, long value)
{
if (value == 0) {
return followingPeerGroupStart;
}
// TODO: Optimize this to *not* look for peers often, probably have pageIndex keep the peer groups
int followingPeerGroupEnd = 0;
int currentValue = 0;
while (currentValue < value) {
boolean peerFound = false;
followingPeerGroupEnd = followingPeerGroupStart + 1;
while ((followingPeerGroupEnd < partitionEnd) && pagesIndex.positionEqualsPosition(peerGroupHashStrategy, followingPeerGroupStart, followingPeerGroupEnd)) {
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What if there are no peers, just each row is a distinct value within the partition?
You'd never set peerFound = true, IIUC so this loop would never end?
Can you explain this to me?

followingPeerGroupEnd++;
peerFound = true;
}
if (followingPeerGroupEnd >= partitionEnd) {
return endPosition;
}

if (!peerFound) {
currentValue++;
}
followingPeerGroupStart++;
}
return followingPeerGroupEnd;
}

private boolean emptyFrame(FrameInfo frameInfo, int rowPosition, int position)
{
FrameBound.Type startType = frameInfo.getStartType();
FrameBound.Type endType = frameInfo.getEndType();

int positions = endPosition - rowPosition;

if ((startType == UNBOUNDED_PRECEDING) && (endType == PRECEDING)) {
return getEndValue(frameInfo) > rowPosition;
}

if ((startType == FOLLOWING) && (endType == UNBOUNDED_FOLLOWING)) {
return getStartValue(frameInfo) > positions;
return getStartValue(frameInfo) > position;
}

if (startType != endType) {
Expand All @@ -225,7 +290,7 @@ private boolean emptyFrame(FrameInfo frameInfo, int rowPosition, int endPosition
return (start < end) || ((start > rowPosition) && (end > rowPosition));
}

return (start > end) || ((start > positions) && (end > positions));
return (start > end) || ((start > position) && (end > position));
}

private static int preceding(int rowPosition, long value)
Expand Down
7 changes: 0 additions & 7 deletions presto-main/src/main/java/com/facebook/presto/sql/analyzer/StatementAnalyzer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -187,7 +187,6 @@
import static com.facebook.presto.sql.tree.FrameBound.Type.PRECEDING;
import static com.facebook.presto.sql.tree.FrameBound.Type.UNBOUNDED_FOLLOWING;
import static com.facebook.presto.sql.tree.FrameBound.Type.UNBOUNDED_PRECEDING;
import static com.facebook.presto.sql.tree.WindowFrame.Type.RANGE;
import static com.facebook.presto.type.UnknownType.UNKNOWN;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkState;
Expand Down Expand Up @@ -1260,12 +1259,6 @@ private void analyzeWindowFrame(WindowFrame frame)
if ((startType == FOLLOWING) && (endType == CURRENT_ROW)) {
throw new SemanticException(INVALID_WINDOW_FRAME, frame, "Window frame starting from FOLLOWING cannot end with CURRENT ROW");
}
if ((frame.getType() == RANGE) && ((startType == PRECEDING) || (endType == PRECEDING))) {
throw new SemanticException(INVALID_WINDOW_FRAME, frame, "Window frame RANGE PRECEDING is only supported with UNBOUNDED");
}
if ((frame.getType() == RANGE) && ((startType == FOLLOWING) || (endType == FOLLOWING))) {
throw new SemanticException(INVALID_WINDOW_FRAME, frame, "Window frame RANGE FOLLOWING is only supported with UNBOUNDED");
}
}

private void analyzeHaving(QuerySpecification node, Scope scope)
Expand Down
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