/**
* Replace old POLocalRearrange with new pre-combine LR, add new map foreach, new
* map-local-rearrange, and connect them
*
* @param mapPlan
* @param preCombinerLR
* @param mfe
* @param mapAgg
* @param mlr
* @throws PlanException
*/
private static void patchUpMap(
PhysicalPlan mapPlan,
POPreCombinerLocalRearrange preCombinerLR,
POForEach mfe,
POPartialAgg mapAgg,
POLocalRearrange mlr)
throws PlanException {
POLocalRearrange oldLR = (POLocalRearrange) mapPlan.getLeaves().get(0);
mapPlan.replace(oldLR, preCombinerLR);
mapPlan.add(mfe);
mapPlan.connect(preCombinerLR, mfe);
// the operator before local rearrange
PhysicalOperator opBeforeLR = mfe;
if (mapAgg != null) {
mapPlan.add(mapAgg);
mapPlan.connect(mfe, mapAgg);
opBeforeLR = mapAgg;
}
mapPlan.add(mlr);
mapPlan.connect(opBeforeLR, mlr);
}
// Tests Single input case for both blocking and non-blocking
// with both map and reduce phases
@Test
public void testSim1() throws Exception {
PhysicalPlan php = new PhysicalPlan();
POLoad ld = GenPhyOp.topLoadOp();
php.add(ld);
PhysicalPlan grpChain1 = GenPhyOp.grpChain();
php.merge(grpChain1);
php.connect(ld, grpChain1.getRoots().get(0));
PhysicalOperator leaf = php.getLeaves().get(0);
PhysicalPlan grpChain2 = GenPhyOp.grpChain();
php.merge(grpChain2);
php.connect(leaf, grpChain2.getRoots().get(0));
leaf = php.getLeaves().get(0);
POFilter fl = GenPhyOp.topFilterOp();
php.add(fl);
php.connect(leaf, fl);
POStore st = GenPhyOp.topStoreOp();
php.add(st);
php.connect(fl, st);
run(php, "test/org/apache/pig/test/data/GoldenFiles/MRC1.gld");
}
/**
* add algebraic functions with appropriate projection to new foreach in combiner
*
* @param cfe - the new foreach in combiner
* @param op2newpos - mapping of physical operator to position in input
* @throws CloneNotSupportedException
* @throws PlanException
*/
private static void addAlgebraicFuncToCombineFE(
POForEach cfe, Map<PhysicalOperator, Integer> op2newpos)
throws CloneNotSupportedException, PlanException {
// an array that we will first populate with physical operators in order
// of their position in input. Used while adding plans to combine
// foreach just so that output of combine foreach same positions as
// input. That means the same operator to position mapping can be used
// by reduce as well
PhysicalOperator[] opsInOrder = new PhysicalOperator[op2newpos.size() + 1];
for (Map.Entry<PhysicalOperator, Integer> op2pos : op2newpos.entrySet()) {
opsInOrder[op2pos.getValue()] = op2pos.getKey();
}
// first position is used by group column and a plan has been added for
// it, so start with 1
for (int i = 1; i < opsInOrder.length; i++) {
// create new inner plan for foreach add cloned copy of given
// physical operator and a new project. Even if the udf in query
// takes multiple input, only one project needs to be added because
// input to this udf will be the INITIAL version of udf evaluated in
// map.
PhysicalPlan newPlan = new PhysicalPlan();
PhysicalOperator newOp = opsInOrder[i].clone();
newPlan.add(newOp);
POProject proj = new POProject(createOperatorKey(cfe.getOperatorKey().getScope()), 1, i);
proj.setResultType(DataType.BAG);
newPlan.add(proj);
newPlan.connect(proj, newOp);
cfe.addInputPlan(newPlan, false);
}
}
public void testLimit() throws Exception {
PhysicalPlan php = new PhysicalPlan();
POLoad lC = GenPhyOp.topLoadOp();
php.add(lC);
POLimit op = new POLimit(new OperatorKey("", r.nextLong()), -1, null);
php.add(op);
php.connect(lC, op);
POStore st = GenPhyOp.topStoreOp();
php.addAsLeaf(st);
run(php, "test/org/apache/pig/test/data/GoldenFiles/MRC17.gld");
}
@Test
public void testSim4() throws Exception {
PhysicalPlan php = new PhysicalPlan();
PhysicalPlan ldGrpChain1 = GenPhyOp.loadedGrpChain();
PhysicalPlan ldGrpChain2 = GenPhyOp.loadedGrpChain();
php.merge(ldGrpChain1);
php.merge(ldGrpChain2);
POUnion un = GenPhyOp.topUnionOp();
php.addAsLeaf(un);
PhysicalPlan ldFil1 = GenPhyOp.loadedFilter();
PhysicalPlan ldFil2 = GenPhyOp.loadedFilter();
php.merge(ldFil1);
php.connect(ldFil1.getLeaves().get(0), un);
php.merge(ldFil2);
php.connect(ldFil2.getLeaves().get(0), un);
POStore st = GenPhyOp.topStoreOp();
php.add(st);
php.connect(un, st);
run(php, "test/org/apache/pig/test/data/GoldenFiles/MRC4.gld");
}
@Test
public void testSpl2() throws Exception {
PhysicalPlan php = new PhysicalPlan();
POLoad lA = GenPhyOp.topLoadOp();
POSplit spl = GenPhyOp.topSplitOp();
php.add(lA);
php.add(spl);
php.connect(lA, spl);
POFilter fl1 = GenPhyOp.topFilterOp();
POFilter fl2 = GenPhyOp.topFilterOp();
php.add(fl1);
php.add(fl2);
php.connect(spl, fl1);
php.connect(spl, fl2);
POLocalRearrange lr1 = GenPhyOp.topLocalRearrangeOp();
POLocalRearrange lr2 = GenPhyOp.topLocalRearrangeOp();
php.add(lr1);
php.add(lr2);
php.connect(fl1, lr1);
php.connect(fl2, lr2);
POGlobalRearrange gr = GenPhyOp.topGlobalRearrangeOp();
php.addAsLeaf(gr);
POPackage pk = GenPhyOp.topPackageOp();
php.addAsLeaf(pk);
POSplit sp2 = GenPhyOp.topSplitOp();
php.addAsLeaf(sp2);
POFilter fl3 = GenPhyOp.topFilterOp();
POFilter fl4 = GenPhyOp.topFilterOp();
php.add(fl3);
php.add(fl4);
php.connect(sp2, fl3);
php.connect(sp2, fl4);
POUnion un = GenPhyOp.topUnionOp();
php.addAsLeaf(un);
POStore st = GenPhyOp.topStoreOp();
php.addAsLeaf(st);
run(php, "test/org/apache/pig/test/data/GoldenFiles/MRC13.gld");
}
/**
* Recursively clone op and its predecessors from pplan and add them to newplan
*
* @param op
* @param pplan
* @param newplan
* @return
* @throws CloneNotSupportedException
* @throws PlanException
*/
private static PhysicalOperator addPredecessorsToPlan(
PhysicalOperator op, PhysicalPlan pplan, PhysicalPlan newplan)
throws CloneNotSupportedException, PlanException {
PhysicalOperator newOp = op.clone();
newplan.add(newOp);
if (pplan.getPredecessors(op) == null || pplan.getPredecessors(op).size() == 0) {
return newOp;
}
for (PhysicalOperator pred : pplan.getPredecessors(op)) {
PhysicalOperator newPred = addPredecessorsToPlan(pred, pplan, newplan);
newplan.connect(newPred, newOp);
}
return newOp;
}
/**
* Create a new foreach with same scope,alias as given foreach add an inner plan that projects the
* group column, which is going to be the first input
*
* @param foreach source foreach
* @param keyType type for group-by key
* @return new POForeach
*/
private static POForEach createForEachWithGrpProj(POForEach foreach, byte keyType) {
String scope = foreach.getOperatorKey().scope;
POForEach newFE = new POForEach(createOperatorKey(scope), new ArrayList<PhysicalPlan>());
newFE.addOriginalLocation(foreach.getAlias(), foreach.getOriginalLocations());
newFE.setResultType(foreach.getResultType());
// create plan that projects the group column
PhysicalPlan grpProjPlan = new PhysicalPlan();
// group by column is the first column
POProject proj = new POProject(createOperatorKey(scope), 1, 0);
proj.setResultType(keyType);
grpProjPlan.add(proj);
newFE.addInputPlan(grpProjPlan, false);
return newFE;
}
/**
* @param op
* @param index
* @param plan
* @throws PlanException
*/
private static void setProjectInput(PhysicalOperator op, PhysicalPlan plan, int index)
throws PlanException {
String scope = op.getOperatorKey().scope;
POProject proj =
new POProject(
new OperatorKey(scope, NodeIdGenerator.getGenerator().getNextNodeId(scope)),
op.getRequestedParallelism(),
index);
proj.setResultType(DataType.BAG);
// Remove old connections and elements from the plan
plan.trimAbove(op);
plan.add(proj);
plan.connect(proj, op);
List<PhysicalOperator> inputs = Lists.newArrayList();
inputs.add(proj);
op.setInputs(inputs);
}
/**
* create new Local rearrange by cloning existing rearrange and add plan for projecting the key
*
* @param rearrange
* @return
* @throws PlanException
* @throws CloneNotSupportedException
*/
private static POLocalRearrange getNewRearrange(POLocalRearrange rearrange)
throws PlanException, CloneNotSupportedException {
POLocalRearrange newRearrange = rearrange.clone();
// Set the projection to be the key
PhysicalPlan newPlan = new PhysicalPlan();
String scope = newRearrange.getOperatorKey().scope;
POProject proj =
new POProject(
new OperatorKey(scope, NodeIdGenerator.getGenerator().getNextNodeId(scope)), -1, 0);
proj.setResultType(newRearrange.getKeyType());
newPlan.add(proj);
List<PhysicalPlan> plans = new ArrayList<PhysicalPlan>(1);
plans.add(newPlan);
newRearrange.setPlansFromCombiner(plans);
return newRearrange;
}
public void testSpl1() throws Exception {
PhysicalPlan php = new PhysicalPlan();
POLoad lA = GenPhyOp.topLoadOp();
POSplit spl = GenPhyOp.topSplitOp();
php.add(lA);
php.add(spl);
php.connect(lA, spl);
POFilter fl1 = GenPhyOp.topFilterOp();
POFilter fl2 = GenPhyOp.topFilterOp();
php.add(fl1);
php.add(fl2);
php.connect(spl, fl1);
php.connect(spl, fl2);
POLocalRearrange lr1 = GenPhyOp.topLocalRearrangeOp();
POLocalRearrange lr2 = GenPhyOp.topLocalRearrangeOp();
php.add(lr1);
php.add(lr2);
php.connect(fl1, lr1);
php.connect(fl2, lr2);
POGlobalRearrange gr = GenPhyOp.topGlobalRearrangeOp();
php.add(gr);
php.connect(lr1, gr);
php.connect(lr2, gr);
POPackage pk = GenPhyOp.topPackageOp();
php.add(pk);
php.connect(gr, pk);
POStore st = GenPhyOp.topStoreOp();
php.add(st);
php.connect(pk, st);
run(php, "test/org/apache/pig/test/data/GoldenFiles/MRC12.gld");
}
@Test
public void testSortUDF1() throws Exception {
PhysicalPlan php = new PhysicalPlan();
PhysicalPlan ldFil1 = GenPhyOp.loadedFilter();
php.merge(ldFil1);
// set up order by *
String funcName = WeirdComparator.class.getName();
POUserComparisonFunc comparator =
new POUserComparisonFunc(
new OperatorKey("", r.nextLong()), -1, null, new FuncSpec(funcName));
POSort sort =
new POSort(
new OperatorKey("", r.nextLong()),
-1,
ldFil1.getLeaves(),
null,
new ArrayList<Boolean>(),
comparator);
sort.setRequestedParallelism(20);
PhysicalPlan nesSortPlan = new PhysicalPlan();
POProject topPrj = new POProject(new OperatorKey("", r.nextLong()));
topPrj.setColumn(1);
topPrj.setOverloaded(true);
topPrj.setResultType(DataType.TUPLE);
nesSortPlan.add(topPrj);
POProject prjStar2 = new POProject(new OperatorKey("", r.nextLong()));
prjStar2.setResultType(DataType.TUPLE);
prjStar2.setStar(true);
nesSortPlan.add(prjStar2);
nesSortPlan.connect(topPrj, prjStar2);
List<PhysicalPlan> nesSortPlanLst = new ArrayList<PhysicalPlan>();
nesSortPlanLst.add(nesSortPlan);
sort.setSortPlans(nesSortPlanLst);
php.add(sort);
php.connect(ldFil1.getLeaves().get(0), sort);
// have a foreach which takes the sort output
// and send it two two udfs
List<String> udfs = new ArrayList<String>();
udfs.add(COUNT.class.getName());
udfs.add(SUM.class.getName());
POForEach fe3 = GenPhyOp.topForEachOPWithUDF(udfs);
php.add(fe3);
php.connect(sort, fe3);
// add a group above the foreach
PhysicalPlan grpChain1 = GenPhyOp.grpChain();
php.merge(grpChain1);
php.connect(fe3, grpChain1.getRoots().get(0));
udfs.clear();
udfs.add(AVG.class.getName());
POForEach fe4 = GenPhyOp.topForEachOPWithUDF(udfs);
php.addAsLeaf(fe4);
PhysicalPlan grpChain2 = GenPhyOp.grpChain();
php.merge(grpChain2);
php.connect(fe4, grpChain2.getRoots().get(0));
udfs.clear();
udfs.add(GFCross.class.getName() + "('1')");
POForEach fe5 = GenPhyOp.topForEachOPWithUDF(udfs);
php.addAsLeaf(fe5);
POStore st = GenPhyOp.topStoreOp();
php.addAsLeaf(st);
run(php, "test/org/apache/pig/test/data/GoldenFiles/MRC15.gld");
}
@Test
public void testSpl3() throws Exception {
PhysicalPlan php = new PhysicalPlan();
POLoad lA = GenPhyOp.topLoadOp();
POSplit spl = GenPhyOp.topSplitOp();
php.add(lA);
php.add(spl);
php.connect(lA, spl);
POFilter fl1 = GenPhyOp.topFilterOp();
fl1.setRequestedParallelism(10);
POFilter fl2 = GenPhyOp.topFilterOp();
fl2.setRequestedParallelism(20);
php.add(fl1);
php.add(fl2);
php.connect(spl, fl1);
php.connect(spl, fl2);
POSplit sp11 = GenPhyOp.topSplitOp();
POSplit sp21 = GenPhyOp.topSplitOp();
php.add(sp11);
php.add(sp21);
php.connect(fl1, sp11);
php.connect(fl2, sp21);
POFilter fl11 = GenPhyOp.topFilterOp();
fl11.setRequestedParallelism(10);
POFilter fl21 = GenPhyOp.topFilterOp();
fl21.setRequestedParallelism(20);
POFilter fl22 = GenPhyOp.topFilterOp();
fl22.setRequestedParallelism(30);
php.add(fl11);
php.add(fl21);
php.add(fl22);
php.connect(sp11, fl11);
php.connect(sp21, fl21);
php.connect(sp21, fl22);
POLocalRearrange lr1 = GenPhyOp.topLocalRearrangeOp();
lr1.setRequestedParallelism(40);
POLocalRearrange lr21 = GenPhyOp.topLocalRearrangeOp();
lr21.setRequestedParallelism(15);
POLocalRearrange lr22 = GenPhyOp.topLocalRearrangeOp();
lr22.setRequestedParallelism(35);
php.add(lr1);
php.add(lr21);
php.add(lr22);
php.connect(fl11, lr1);
php.connect(fl21, lr21);
php.connect(fl22, lr22);
POGlobalRearrange gr = GenPhyOp.topGlobalRearrangeOp();
php.addAsLeaf(gr);
POPackage pk = GenPhyOp.topPackageOp();
pk.setRequestedParallelism(25);
php.addAsLeaf(pk);
POSplit sp2 = GenPhyOp.topSplitOp();
php.addAsLeaf(sp2);
POFilter fl3 = GenPhyOp.topFilterOp();
fl3.setRequestedParallelism(100);
POFilter fl4 = GenPhyOp.topFilterOp();
fl4.setRequestedParallelism(80);
php.add(fl3);
php.add(fl4);
php.connect(sp2, fl3);
php.connect(sp2, fl4);
POUnion un = GenPhyOp.topUnionOp();
php.addAsLeaf(un);
POStore st = GenPhyOp.topStoreOp();
php.addAsLeaf(st);
run(php, "test/org/apache/pig/test/data/GoldenFiles/MRC14.gld");
}
@Test
public void testRun2() throws Exception {
PhysicalPlan php = new PhysicalPlan();
PhysicalPlan part1 = new PhysicalPlan();
POLoad lC = GenPhyOp.topLoadOp();
POFilter fC = GenPhyOp.topFilterOp();
POLocalRearrange lrC = GenPhyOp.topLocalRearrangeOp();
POGlobalRearrange grC = GenPhyOp.topGlobalRearrangeOp();
POPackage pkC = GenPhyOp.topPackageOp();
part1.add(lC);
part1.add(fC);
part1.connect(lC, fC);
part1.add(lrC);
part1.connect(fC, lrC);
part1.add(grC);
part1.connect(lrC, grC);
part1.add(pkC);
part1.connect(grC, pkC);
POPackage pkD = GenPhyOp.topPackageOp();
POLocalRearrange lrD = GenPhyOp.topLocalRearrangeOp();
POGlobalRearrange grD = GenPhyOp.topGlobalRearrangeOp();
POLoad lD = GenPhyOp.topLoadOp();
part1.add(lD);
part1.add(lrD);
part1.connect(lD, lrD);
part1.add(grD);
part1.connect(lrD, grD);
part1.add(pkD);
part1.connect(grD, pkD);
part1.connect(pkD, grC);
POLoad lA = GenPhyOp.topLoadOp();
POLoad lB = GenPhyOp.topLoadOp();
// POLoad lC = lA;
POFilter fA = GenPhyOp.topFilterOp();
POLocalRearrange lrA = GenPhyOp.topLocalRearrangeOp();
POLocalRearrange lrB = GenPhyOp.topLocalRearrangeOp();
POGlobalRearrange grAB = GenPhyOp.topGlobalRearrangeOp();
POPackage pkAB = GenPhyOp.topPackageOp();
POFilter fAB = GenPhyOp.topFilterOp();
POUnion unABC = GenPhyOp.topUnionOp();
php.add(lA);
php.add(lB);
php.add(fA);
php.connect(lA, fA);
php.add(lrA);
php.add(lrB);
php.connect(fA, lrA);
php.connect(lB, lrB);
php.add(grAB);
php.connect(lrA, grAB);
php.connect(lrB, grAB);
php.add(pkAB);
php.connect(grAB, pkAB);
php.add(fAB);
php.connect(pkAB, fAB);
php.merge(part1);
List<PhysicalOperator> leaves = new ArrayList<PhysicalOperator>();
for (PhysicalOperator phyOp : php.getLeaves()) {
leaves.add(phyOp);
}
php.add(unABC);
for (PhysicalOperator physicalOperator : leaves) {
php.connect(physicalOperator, unABC);
}
POStore st = GenPhyOp.topStoreOp();
php.add(st);
php.connect(unABC, st);
run(php, "test/org/apache/pig/test/data/GoldenFiles/MRC11.gld");
}
/**
* Algebraic functions and distinct in nested plan of a foreach are partially computed in the map
* and combine phase. A new foreach statement with initial and intermediate forms of algebraic
* functions are added to map and combine plans respectively.
*
* <p>If bag portion of group-by result is projected or a non algebraic expression/udf has bag as
* input, combiner will not be used. This is because the use of combiner in such case is likely to
* degrade performance as there will not be much reduction in data size in combine stage to offset
* the cost of the additional number of times (de)serialization is done.
*
* <p>Major areas for enhancement: 1. use of combiner in cogroup 2. queries with order-by, limit
* or sort in a nested foreach after group-by 3. case where group-by is followed by filter that
* has algebraic expression
*/
public static void addCombiner(
PhysicalPlan mapPlan,
PhysicalPlan reducePlan,
PhysicalPlan combinePlan,
CompilationMessageCollector messageCollector,
boolean doMapAgg)
throws VisitorException {
// part one - check if this MR job represents a group-by + foreach. Find
// the POLocalRearrange in the map. I'll need it later.
List<PhysicalOperator> mapLeaves = mapPlan.getLeaves();
if (mapLeaves == null || mapLeaves.size() != 1) {
messageCollector.collect(
"Expected map to have single leaf", MessageType.Warning, PigWarning.MULTI_LEAF_MAP);
return;
}
PhysicalOperator mapLeaf = mapLeaves.get(0);
if (!(mapLeaf instanceof POLocalRearrange)) {
return;
}
POLocalRearrange rearrange = (POLocalRearrange) mapLeaf;
List<PhysicalOperator> reduceRoots = reducePlan.getRoots();
if (reduceRoots.size() != 1) {
messageCollector.collect(
"Expected reduce to have single root", MessageType.Warning, PigWarning.MULTI_ROOT_REDUCE);
return;
}
// I expect that the first root should always be a POPackage. If not, I
// don't know what's going on, so I'm out of here.
PhysicalOperator root = reduceRoots.get(0);
if (!(root instanceof POPackage)) {
messageCollector.collect(
"Expected reduce root to be a POPackage",
MessageType.Warning,
PigWarning.NON_PACKAGE_REDUCE_PLAN_ROOT);
return;
}
POPackage pack = (POPackage) root;
List<PhysicalOperator> packSuccessors = reducePlan.getSuccessors(root);
if (packSuccessors == null || packSuccessors.size() != 1) {
return;
}
PhysicalOperator successor = packSuccessors.get(0);
if (successor instanceof POLimit) {
// POLimit is acceptable, as long has it has a single foreach as
// successor
List<PhysicalOperator> limitSucs = reducePlan.getSuccessors(successor);
if (limitSucs != null && limitSucs.size() == 1 && limitSucs.get(0) instanceof POForEach) {
// the code below will now further examine the foreach
successor = limitSucs.get(0);
}
}
if (successor instanceof POForEach) {
POForEach foreach = (POForEach) successor;
List<PhysicalPlan> feInners = foreach.getInputPlans();
// find algebraic operators and also check if the foreach statement
// is suitable for combiner use
List<Pair<PhysicalOperator, PhysicalPlan>> algebraicOps = findAlgebraicOps(feInners);
if (algebraicOps == null || algebraicOps.size() == 0) {
// the plan is not combinable or there is nothing to combine
// we're done
return;
}
if (combinePlan != null && combinePlan.getRoots().size() != 0) {
messageCollector.collect(
"Wasn't expecting to find anything already " + "in the combiner!",
MessageType.Warning,
PigWarning.NON_EMPTY_COMBINE_PLAN);
return;
}
LOG.info("Choosing to move algebraic foreach to combiner");
try {
// replace PODistinct->Project[*] with distinct udf (which is Algebraic)
for (Pair<PhysicalOperator, PhysicalPlan> op2plan : algebraicOps) {
if (!(op2plan.first instanceof PODistinct)) {
continue;
}
DistinctPatcher distinctPatcher = new DistinctPatcher(op2plan.second);
distinctPatcher.visit();
if (distinctPatcher.getDistinct() == null) {
int errCode = 2073;
String msg =
"Problem with replacing distinct operator with distinct built-in function.";
throw new PlanException(msg, errCode, PigException.BUG);
}
op2plan.first = distinctPatcher.getDistinct();
}
// create new map foreach
POForEach mfe = createForEachWithGrpProj(foreach, rearrange.getKeyType());
Map<PhysicalOperator, Integer> op2newpos = Maps.newHashMap();
Integer pos = 1;
// create plan for each algebraic udf and add as inner plan in map-foreach
for (Pair<PhysicalOperator, PhysicalPlan> op2plan : algebraicOps) {
PhysicalPlan udfPlan = createPlanWithPredecessors(op2plan.first, op2plan.second);
mfe.addInputPlan(udfPlan, false);
op2newpos.put(op2plan.first, pos++);
}
changeFunc(mfe, POUserFunc.INITIAL);
// since we will only be creating SingleTupleBag as input to
// the map foreach, we should flag the POProjects in the map
// foreach inner plans to also use SingleTupleBag
for (PhysicalPlan mpl : mfe.getInputPlans()) {
try {
new fixMapProjects(mpl).visit();
} catch (VisitorException e) {
int errCode = 2089;
String msg = "Unable to flag project operator to use single tuple bag.";
throw new PlanException(msg, errCode, PigException.BUG, e);
}
}
// create new combine foreach
POForEach cfe = createForEachWithGrpProj(foreach, rearrange.getKeyType());
// add algebraic functions with appropriate projection
addAlgebraicFuncToCombineFE(cfe, op2newpos);
changeFunc(cfe, POUserFunc.INTERMEDIATE);
// fix projection and function time for algebraic functions in reduce foreach
for (Pair<PhysicalOperator, PhysicalPlan> op2plan : algebraicOps) {
setProjectInput(op2plan.first, op2plan.second, op2newpos.get(op2plan.first));
byte resultType = op2plan.first.getResultType();
((POUserFunc) op2plan.first).setAlgebraicFunction(POUserFunc.FINAL);
op2plan.first.setResultType(resultType);
}
// we have modified the foreach inner plans - so set them again
// for the foreach so that foreach can do any re-initialization
// around them.
// FIXME - this is a necessary evil right now because the leaves
// are explicitly stored in the POForeach as a list rather than
// computed each time at run time from the plans for
// optimization. Do we want to have the Foreach compute the
// leaves each time and have Java optimize it (will Java
// optimize?)?
mfe.setInputPlans(mfe.getInputPlans());
cfe.setInputPlans(cfe.getInputPlans());
foreach.setInputPlans(foreach.getInputPlans());
// tell POCombinerPackage which fields need projected and which
// placed in bags. First field is simple project rest need to go
// into bags
int numFields = algebraicOps.size() + 1; // algebraic funcs + group key
boolean[] bags = new boolean[numFields];
bags[0] = false;
for (int i = 1; i < numFields; i++) {
bags[i] = true;
}
// Use the POCombiner package in the combine plan
// as it needs to act differently than the regular
// package operator.
CombinerPackager pkgr = new CombinerPackager(pack.getPkgr(), bags);
POPackage combinePack = pack.clone();
combinePack.setPkgr(pkgr);
combinePack.setParentPlan(null);
combinePlan.add(combinePack);
combinePlan.add(cfe);
combinePlan.connect(combinePack, cfe);
// No need to connect projections in cfe to cp, because
// PigCombiner directly attaches output from package to
// root of remaining plan.
POLocalRearrange mlr = getNewRearrange(rearrange);
POPartialAgg mapAgg = null;
if (doMapAgg) {
mapAgg = createPartialAgg(cfe);
}
// A specialized local rearrange operator will replace
// the normal local rearrange in the map plan. This behaves
// like the regular local rearrange in the getNext()
// as far as getting its input and constructing the
// "key" out of the input. It then returns a tuple with
// two fields - the key in the first position and the
// "value" inside a bag in the second position. This output
// format resembles the format out of a Package. This output
// will feed to the map foreach which expects this format.
// If the key field isn't in the project of the combiner or map foreach,
// it is added to the end (This is required so that we can
// set up the inner plan of the new Local Rearrange leaf in the map
// and combine plan to contain just the project of the key).
patchUpMap(mapPlan, getPreCombinerLR(rearrange), mfe, mapAgg, mlr);
POLocalRearrange clr = getNewRearrange(rearrange);
clr.setParentPlan(null);
combinePlan.add(clr);
combinePlan.connect(cfe, clr);
// Change the package operator in the reduce plan to
// be the POCombiner package, as it needs to act
// differently than the regular package operator.
pack.setPkgr(pkgr.clone());
} catch (Exception e) {
int errCode = 2018;
String msg = "Internal error. Unable to introduce the combiner for optimization.";
throw new OptimizerException(msg, errCode, PigException.BUG, e);
}
}
}