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Avoid caching full query result for queries with generic sort and LIM… #121

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Avoid caching full query result for queries with generic sort and LIM…
markoszah Jun 4, 2024
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markoszah Jun 5, 2024
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10 changes: 5 additions & 5 deletions driver/src/main/java/oracle/nosql/driver/http/Client.java
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Original file line number Diff line number Diff line change
Expand Up @@ -630,7 +630,7 @@ public Result execute(Request kvRequest) {
*/
kvRequest.setTimeoutInternal(thisIterationTimeoutMs);
serialVersionUsed = writeContent(buffer, kvRequest,
queryVersionUsed);
queryVersionUsed);
kvRequest.setTimeoutInternal(timeoutMs);

/*
Expand Down Expand Up @@ -1616,11 +1616,11 @@ private synchronized boolean decrementQueryVersion(short versionUsed) {
if (queryVersion != versionUsed) {
return true;
}
if (queryVersion == QueryDriver.QUERY_V4) {
queryVersion = QueryDriver.QUERY_V3;
return true;
if (queryVersion == QueryDriver.QUERY_V3) {
return false;
}
return false;
--queryVersion;
return true;
}

/**
Expand Down
6 changes: 3 additions & 3 deletions driver/src/main/java/oracle/nosql/driver/ops/serde/nson/NsonSerializerFactory.java
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Original file line number Diff line number Diff line change
Expand Up @@ -1008,7 +1008,7 @@ private static void deserializePrepareOrQuery(

} else if (name.equals(DRIVER_QUERY_PLAN)) {
dpi = getDriverPlanInfo(Nson.readNsonBinary(in),
serialVersion);
queryVersion);

} else if (name.equals(REACHED_LIMIT) && qres != null) {
qres.setReachedLimit(Nson.readNsonBoolean(in));
Expand Down Expand Up @@ -1179,15 +1179,15 @@ private static void readPhase1Results(byte[] arr, QueryResult result)
}

private static DriverPlanInfo getDriverPlanInfo(byte[] arr,
short serialVersion)
short queryVersion)
throws IOException {
if (arr == null || arr.length == 0) {
return null;
}
ByteBuf buf = Unpooled.wrappedBuffer(arr);
ByteInputStream bis = new NettyByteInputStream(buf);
DriverPlanInfo dpi = new DriverPlanInfo();
dpi.driverQueryPlan = PlanIter.deserializeIter(bis, serialVersion);
dpi.driverQueryPlan = PlanIter.deserializeIter(bis, queryVersion);
if (dpi.driverQueryPlan == null) {
return null;
}
Expand Down
3 changes: 3 additions & 0 deletions driver/src/main/java/oracle/nosql/driver/query/PlanIter.java
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Original file line number Diff line number Diff line change
Expand Up @@ -306,6 +306,9 @@ protected abstract void displayContent(
StringBuilder sb,
QueryFormatter formatter);

/*
* Note: the serialVersion param is actually the queryVersion.
*/
public static PlanIter deserializeIter(
ByteInputStream in,
short serialVersion) throws IOException {
Expand Down
5 changes: 4 additions & 1 deletion driver/src/main/java/oracle/nosql/driver/query/QueryDriver.java
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Original file line number Diff line number Diff line change
Expand Up @@ -35,7 +35,10 @@ public class QueryDriver {
/* added query name in QueryRequest */
public static short QUERY_V4 = 4;

public static short QUERY_VERSION = QUERY_V4;
/* added limit iter field in SortIter */
public static short QUERY_V5 = 5;

public static short QUERY_VERSION = QUERY_V5;

private static final int BATCH_SIZE = 100;

Expand Down
193 changes: 169 additions & 24 deletions driver/src/main/java/oracle/nosql/driver/query/SortIter.java
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Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@
import java.io.IOException;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.PriorityQueue;

import oracle.nosql.driver.query.PlanIterState.StateEnum;
import oracle.nosql.driver.util.ByteInputStream;
Expand All @@ -25,35 +26,94 @@
*/
public class SortIter extends PlanIter {

private class CompareFunction implements Comparator<MapValue> {

RuntimeControlBlock theRCB;

CompareFunction(RuntimeControlBlock rcb) {
theRCB = rcb;
}

@Override
public int compare(MapValue v1, MapValue v2) {

return Compare.sortResults(theRCB,
v1,
v2,
theSortFields,
theSortSpecs);
}
}

private static class ReverseCompareFunction implements Comparator<MapValue> {

CompareFunction theComparator;

ReverseCompareFunction(CompareFunction comparator) {
theComparator = comparator;
}

@Override
public int compare(MapValue v1, MapValue v2) {
return -theComparator.compare(v1, v2);
}
}

private static class SortIterState extends PlanIterState {

final ArrayList<MapValue> theResults;
CompareFunction theComparator;

int theLimit = -1;

ArrayList<MapValue> theResults;
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Please add some comments here that explain why there are three collections (list, queue, array) and when/how each are used.

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Done.


PriorityQueue<MapValue> theResultsQueue;

MapValue[] theResultsArray;

int theNumResults;

int theCurrResult;

public SortIterState() {
public SortIterState(RuntimeControlBlock rcb, SortIter iter, int limit) {
super();
theResults = new ArrayList<MapValue>(128);
theLimit = limit;
if (theLimit > 0) {
theResults = new ArrayList<MapValue>(theLimit);
} else {
theResults = new ArrayList<MapValue>(4096);
}
theComparator = iter.new CompareFunction(rcb);
}

@Override
public void done() {
super.done();
theCurrResult = 0;
theResults.clear();
theResults = null;
theResultsQueue = null;
theResultsArray = null;
}

@Override
public void reset(PlanIter iter) {
super.reset(iter);
theCurrResult = 0;
theResults.clear();
theNumResults = 0;
if (theLimit > 0) {
theResults = new ArrayList<MapValue>(theLimit);
} else {
theResults = new ArrayList<MapValue>(4096);
}
theResultsQueue = null;
theResultsArray = null;
}

@Override
public void close() {
super.close();
theResults.clear();
theResults = null;
theResultsQueue = null;
theResultsArray = null;
}
}

Expand All @@ -63,13 +123,15 @@ public void close() {

private final SortSpec[] theSortSpecs;

private final PlanIter theLimit;

private final boolean theCountMemory;

public SortIter(ByteInputStream in, PlanIterKind kind, short serialVersion)
public SortIter(ByteInputStream in, PlanIterKind kind, short queryVersion)
throws IOException {

super(in, serialVersion);
theInput = deserializeIter(in, serialVersion);
super(in, queryVersion);
theInput = deserializeIter(in, queryVersion);

theSortFields = SerializationUtil.readStringArray(in);
theSortSpecs = readSortSpecs(in);
Expand All @@ -79,6 +141,12 @@ public SortIter(ByteInputStream in, PlanIterKind kind, short serialVersion)
} else {
theCountMemory = true;
}

if (queryVersion >= QueryDriver.QUERY_V5) {
theLimit = deserializeIter(in, queryVersion);
} else {
theLimit = null;
}
}

@Override
Expand All @@ -93,7 +161,19 @@ PlanIter getInputIter() {

@Override
public void open(RuntimeControlBlock rcb) {
SortIterState state = new SortIterState();

rcb.trace("Opening SortIter");

int limit = - 1;

if (theLimit != null) {
theLimit.open(rcb);
theLimit.next(rcb);
FieldValue val = rcb.getRegVal(theLimit.getResultReg());
limit = val.getInt();
}

SortIterState state = new SortIterState(rcb, this, limit);
rcb.setState(theStatePos, state);
theInput.open(rcb);
}
Expand Down Expand Up @@ -143,11 +223,55 @@ public boolean next(RuntimeControlBlock rcb) {
}
}

state.theResults.add(v);
if (state.theLimit < 0) {
state.theResults.add(v);

if (theCountMemory) {
long sz = v.sizeof() + SizeOf.OBJECT_REF_OVERHEAD;
rcb.incMemoryConsumption(sz);
}
} else if (state.theResults != null &&
state.theResults.size() < state.theLimit) {

state.theResults.add(v);

if (theCountMemory) {
long sz = v.sizeof() + SizeOf.OBJECT_REF_OVERHEAD;
rcb.incMemoryConsumption(sz);
}

if (state.theResults.size() == state.theLimit) {

if (theCountMemory) {
long sz = v.sizeof() + SizeOf.OBJECT_REF_OVERHEAD;
rcb.incMemoryConsumption(sz);
ReverseCompareFunction comparator =
new ReverseCompareFunction(state.theComparator);

state.theResultsQueue = new PriorityQueue<>(comparator);

for (MapValue result : state.theResults) {
state.theResultsQueue.add(result);
}
state.theResults = null;
}
} else {
MapValue lastResult = state.theResultsQueue.peek();

if (state.theComparator.compare(lastResult, v) > 0) {

state.theResultsQueue.remove();
state.theResultsQueue.add(v);

if (rcb.getTraceLevel() >= 4) {
rcb.trace("SortIter: added top result: " + v +
"\nin place of " + lastResult);
}

if (theCountMemory) {
long sz = v.sizeof();
rcb.incMemoryConsumption(sz);
sz = lastResult.sizeof();
rcb.decMemoryConsumption(sz);
}
}
}

more = theInput.next(rcb);
Expand All @@ -157,22 +281,43 @@ public boolean next(RuntimeControlBlock rcb) {
return false;
}

state.theResults.sort(
(v1, v2) -> Compare.sortResults(rcb,
v1,
v2,
theSortFields,
theSortSpecs));
if (state.theResultsQueue != null) {
/* Move the results from the queue to an array, maintaining their
* sort order. This is needed because iterating over the queue
* using an Iterator does not guarantee that the results will be
* retrieved in their sorted order. */
state.theResultsArray = new MapValue[state.theLimit];

int i = state.theLimit - 1;
while (!state.theResultsQueue.isEmpty()) {
MapValue result = state.theResultsQueue.remove();
state.theResultsArray[i] = result;
--i;
}

state.theResultsQueue = null;
state.theNumResults = state.theLimit;
} else {
state.theResults.sort(state.theComparator);
state.theNumResults = state.theResults.size();
}

state.setState(StateEnum.RUNNING);
}

if (state.theCurrResult < state.theResults.size()) {
if (state.theCurrResult < state.theNumResults) {

MapValue v;
if (state.theResultsArray == null) {
v = state.theResults.get(state.theCurrResult);
state.theResults.set(state.theCurrResult, null);
} else {
v = state.theResultsArray[state.theCurrResult];
state.theResultsArray[state.theCurrResult] = null;
}

MapValue v = state.theResults.get(state.theCurrResult);
v.convertEmptyToNull();
rcb.setRegVal(theResultReg, v);
state.theResults.set(state.theCurrResult, null);
++state.theCurrResult;
return true;
}
Expand Down