Examples with VariableReferenceExpression org.apache.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression used on opensource projects

Example 81 with VariableReferenceExpression

use of org.apache.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression in project asterixdb by apache.

the class RemoveLeftOuterUnnestForLeftOuterJoinRule method removeGroupByAndOuterUnnest.

// Performs the actual rewrite.
private void removeGroupByAndOuterUnnest(Mutable<ILogicalOperator> opRef, IOptimizationContext context, LeftOuterUnnestOperator outerUnnest, GroupByOperator gbyOperator, LeftOuterJoinOperator lojOperator, LogicalVariable listifyVar) throws AlgebricksException {
    List<LogicalVariable> lhs = new ArrayList<>();
    List<Mutable<ILogicalExpression>> rhs = new ArrayList<>();
    lhs.add(outerUnnest.getVariable());
    rhs.add(new MutableObject<ILogicalExpression>(new VariableReferenceExpression(listifyVar)));
    List<Pair<LogicalVariable, Mutable<ILogicalExpression>>> gbyList = gbyOperator.getGroupByList();
    for (Pair<LogicalVariable, Mutable<ILogicalExpression>> gbyPair : gbyList) {
        lhs.add(gbyPair.first);
        rhs.add(gbyPair.second);
    }
    AssignOperator assignOp = new AssignOperator(lhs, rhs);
    assignOp.getInputs().add(new MutableObject<ILogicalOperator>(lojOperator));
    context.computeAndSetTypeEnvironmentForOperator(assignOp);
    opRef.setValue(assignOp);
}

Example 82 with VariableReferenceExpression

use of org.apache.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression in project asterixdb by apache.

the class RemoveRedundantListifyRule method appliesForReverseCase.

private boolean appliesForReverseCase(Mutable<ILogicalOperator> opRef, Set<LogicalVariable> varUsedAbove, IOptimizationContext context) throws AlgebricksException {
    AbstractLogicalOperator op1 = (AbstractLogicalOperator) opRef.getValue();
    if (op1.getOperatorTag() != LogicalOperatorTag.AGGREGATE) {
        return false;
    }
    AggregateOperator agg = (AggregateOperator) op1;
    if (agg.getVariables().size() > 1 || agg.getVariables().size() <= 0) {
        return false;
    }
    LogicalVariable aggVar = agg.getVariables().get(0);
    ILogicalExpression aggFun = agg.getExpressions().get(0).getValue();
    AbstractFunctionCallExpression f = (AbstractFunctionCallExpression) aggFun;
    if (!BuiltinFunctions.LISTIFY.equals(f.getFunctionIdentifier())) {
        return false;
    }
    if (f.getArguments().size() != 1) {
        return false;
    }
    ILogicalExpression arg0 = f.getArguments().get(0).getValue();
    if (((AbstractLogicalExpression) arg0).getExpressionTag() != LogicalExpressionTag.VARIABLE) {
        return false;
    }
    LogicalVariable aggInputVar = ((VariableReferenceExpression) arg0).getVariableReference();
    if (varUsedAbove.contains(aggInputVar)) {
        return false;
    }
    if (agg.getInputs().size() == 0) {
        return false;
    }
    AbstractLogicalOperator op2 = (AbstractLogicalOperator) agg.getInputs().get(0).getValue();
    if (op2.getOperatorTag() != LogicalOperatorTag.UNNEST) {
        return false;
    }
    UnnestOperator unnest = (UnnestOperator) op2;
    if (unnest.getPositionalVariable() != null) {
        return false;
    }
    if (!unnest.getVariable().equals(aggInputVar)) {
        return false;
    }
    ILogicalExpression unnestArg = unnest.getExpressionRef().getValue();
    if (unnestArg.getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) {
        return false;
    }
    AbstractFunctionCallExpression scanFunc = (AbstractFunctionCallExpression) unnestArg;
    if (scanFunc.getFunctionIdentifier() != BuiltinFunctions.SCAN_COLLECTION) {
        return false;
    }
    if (scanFunc.getArguments().size() != 1) {
        return false;
    }
    List<LogicalVariable> assgnVars = new ArrayList<>(1);
    assgnVars.add(aggVar);
    AssignOperator assign = new AssignOperator(assgnVars, scanFunc.getArguments());
    assign.getInputs().add(unnest.getInputs().get(0));
    context.computeAndSetTypeEnvironmentForOperator(assign);
    opRef.setValue(assign);
    return true;
}

Example 83 with VariableReferenceExpression

use of org.apache.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression in project asterixdb by apache.

the class SimilarityCheckRule method replaceWithVariableArg.

private boolean replaceWithVariableArg(Mutable<ILogicalExpression> expRef, FunctionIdentifier normFuncIdent, AsterixConstantValue constVal, VariableReferenceExpression varRefExpr, List<AssignOperator> assigns, IOptimizationContext context) throws AlgebricksException {
    // Find variable in assigns to determine its originating function.
    LogicalVariable var = varRefExpr.getVariableReference();
    Mutable<ILogicalExpression> simFuncExprRef = null;
    ScalarFunctionCallExpression simCheckFuncExpr = null;
    AssignOperator matchingAssign = null;
    for (int i = 0; i < assigns.size(); i++) {
        AssignOperator assign = assigns.get(i);
        for (int j = 0; j < assign.getVariables().size(); j++) {
            // Check if variables match.
            if (var != assign.getVariables().get(j)) {
                continue;
            }
            // Check if corresponding expr is a function call.
            if (assign.getExpressions().get(j).getValue().getExpressionTag() != LogicalExpressionTag.FUNCTION_CALL) {
                continue;
            }
            simFuncExprRef = assign.getExpressions().get(j);
            // Analyze function expression and get equivalent similarity check function.
            simCheckFuncExpr = getSimilarityCheckExpr(normFuncIdent, constVal, (AbstractFunctionCallExpression) simFuncExprRef.getValue());
            matchingAssign = assign;
            break;
        }
        if (simCheckFuncExpr != null) {
            break;
        }
    }
    // Only non-null if we found that varRefExpr refers to an optimizable similarity function call.
    if (simCheckFuncExpr != null) {
        // Create a new assign under matchingAssign which assigns the result of our similarity-check function to a variable.
        LogicalVariable newVar = context.newVar();
        AssignOperator newAssign = new AssignOperator(newVar, new MutableObject<ILogicalExpression>(simCheckFuncExpr));
        // Hook up inputs.
        newAssign.getInputs().add(new MutableObject<ILogicalOperator>(matchingAssign.getInputs().get(0).getValue()));
        matchingAssign.getInputs().get(0).setValue(newAssign);
        // Replace select condition with a get-item on newVarFromExpression.
        List<Mutable<ILogicalExpression>> selectGetItemArgs = new ArrayList<Mutable<ILogicalExpression>>();
        // First arg is a variable reference expr on newVarFromExpression.
        selectGetItemArgs.add(new MutableObject<ILogicalExpression>(new VariableReferenceExpression(newVar)));
        // Second arg is the item index to be accessed, here 0.
        selectGetItemArgs.add(new MutableObject<ILogicalExpression>(new ConstantExpression(new AsterixConstantValue(new AInt32(0)))));
        ILogicalExpression selectGetItemExpr = new ScalarFunctionCallExpression(FunctionUtil.getFunctionInfo(BuiltinFunctions.GET_ITEM), selectGetItemArgs);
        // Replace the old similarity function call with the new getItemExpr.
        expRef.setValue(selectGetItemExpr);
        // Replace expr corresponding to original variable in the original assign with a get-item on
        // newVarFromExpression.
        List<Mutable<ILogicalExpression>> assignGetItemArgs = new ArrayList<Mutable<ILogicalExpression>>();
        // First arg is a variable reference expr on newVarFromExpression.
        assignGetItemArgs.add(new MutableObject<ILogicalExpression>(new VariableReferenceExpression(newVar)));
        // Second arg is the item index to be accessed, here 1.
        assignGetItemArgs.add(new MutableObject<ILogicalExpression>(new ConstantExpression(new AsterixConstantValue(new AInt32(1)))));
        ILogicalExpression assignGetItemExpr = new ScalarFunctionCallExpression(FunctionUtil.getFunctionInfo(BuiltinFunctions.GET_ITEM), assignGetItemArgs);
        // Replace the original assign expr with the get-item expr.
        simFuncExprRef.setValue(assignGetItemExpr);
        context.computeAndSetTypeEnvironmentForOperator(newAssign);
        context.computeAndSetTypeEnvironmentForOperator(matchingAssign);
        return true;
    }
    return false;
}

Example 84 with VariableReferenceExpression

use of org.apache.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression in project asterixdb by apache.

the class IntroduceSelectAccessMethodRule method connectAll2ndarySearchPlanWithIntersect.

/**
     * Connect each secondary index utilization plan to a common INTERSECT operator.
     */
private ILogicalOperator connectAll2ndarySearchPlanWithIntersect(List<ILogicalOperator> subRoots, IOptimizationContext context) throws AlgebricksException {
    ILogicalOperator lop = subRoots.get(0);
    List<List<LogicalVariable>> inputVars = new ArrayList<>(subRoots.size());
    for (int i = 0; i < subRoots.size(); i++) {
        if (lop.getOperatorTag() != subRoots.get(i).getOperatorTag()) {
            throw new AlgebricksException("The data source root should have the same operator type.");
        }
        if (lop.getInputs().size() != 1) {
            throw new AlgebricksException("The primary search has multiple inputs.");
        }
        ILogicalOperator curRoot = subRoots.get(i);
        OrderOperator order = (OrderOperator) curRoot.getInputs().get(0).getValue();
        List<LogicalVariable> orderedColumn = new ArrayList<>(order.getOrderExpressions().size());
        for (Pair<OrderOperator.IOrder, Mutable<ILogicalExpression>> orderExpression : order.getOrderExpressions()) {
            if (orderExpression.second.getValue().getExpressionTag() != LogicalExpressionTag.VARIABLE) {
                throw new AlgebricksException("The order by expression should be variables, but they aren't variables.");
            }
            VariableReferenceExpression orderedVar = (VariableReferenceExpression) orderExpression.second.getValue();
            orderedColumn.add(orderedVar.getVariableReference());
        }
        inputVars.add(orderedColumn);
    }
    List<LogicalVariable> outputVar = inputVars.get(0);
    IntersectOperator intersect = new IntersectOperator(outputVar, inputVars);
    for (ILogicalOperator secondarySearch : subRoots) {
        intersect.getInputs().add(secondarySearch.getInputs().get(0));
    }
    context.computeAndSetTypeEnvironmentForOperator(intersect);
    lop.getInputs().set(0, new MutableObject<>(intersect));
    return lop;
}

Example 85 with VariableReferenceExpression

use of org.apache.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression in project asterixdb by apache.

the class BTreeAccessMethod method createSecondaryToPrimaryPlan.

@Override
public ILogicalOperator createSecondaryToPrimaryPlan(Mutable<ILogicalExpression> conditionRef, OptimizableOperatorSubTree indexSubTree, OptimizableOperatorSubTree probeSubTree, Index chosenIndex, AccessMethodAnalysisContext analysisCtx, boolean retainInput, boolean retainNull, boolean requiresBroadcast, IOptimizationContext context) throws AlgebricksException {
    Dataset dataset = indexSubTree.getDataset();
    ARecordType recordType = indexSubTree.getRecordType();
    ARecordType metaRecordType = indexSubTree.getMetaRecordType();
    // we made sure indexSubTree has datasource scan
    AbstractDataSourceOperator dataSourceOp = (AbstractDataSourceOperator) indexSubTree.getDataSourceRef().getValue();
    List<Pair<Integer, Integer>> exprAndVarList = analysisCtx.getIndexExprsFromIndexExprsAndVars(chosenIndex);
    int numSecondaryKeys = analysisCtx.getNumberOfMatchedKeys(chosenIndex);
    // List of function expressions that will be replaced by the secondary-index search.
    // These func exprs will be removed from the select condition at the very end of this method.
    Set<ILogicalExpression> replacedFuncExprs = new HashSet<>();
    // Info on high and low keys for the BTree search predicate.
    ILogicalExpression[] lowKeyExprs = new ILogicalExpression[numSecondaryKeys];
    ILogicalExpression[] highKeyExprs = new ILogicalExpression[numSecondaryKeys];
    LimitType[] lowKeyLimits = new LimitType[numSecondaryKeys];
    LimitType[] highKeyLimits = new LimitType[numSecondaryKeys];
    boolean[] lowKeyInclusive = new boolean[numSecondaryKeys];
    boolean[] highKeyInclusive = new boolean[numSecondaryKeys];
    ILogicalExpression[] constantAtRuntimeExpressions = new ILogicalExpression[numSecondaryKeys];
    LogicalVariable[] constAtRuntimeExprVars = new LogicalVariable[numSecondaryKeys];
    /* TODO: For now we don't do any sophisticated analysis of the func exprs to come up with "the best" range
         * predicate. If we can't figure out how to integrate a certain funcExpr into the current predicate,
         * we just bail by setting this flag.*/
    boolean couldntFigureOut = false;
    boolean doneWithExprs = false;
    boolean isEqCondition = false;
    BitSet setLowKeys = new BitSet(numSecondaryKeys);
    BitSet setHighKeys = new BitSet(numSecondaryKeys);
    // Go through the func exprs listed as optimizable by the chosen index,
    // and formulate a range predicate on the secondary-index keys.
    // checks whether a type casting happened from a real (FLOAT, DOUBLE) value to an INT value
    // since we have a round issues when dealing with LT(<) OR GT(>) operator.
    boolean realTypeConvertedToIntegerType;
    for (Pair<Integer, Integer> exprIndex : exprAndVarList) {
        // Position of the field of matchedFuncExprs.get(exprIndex) in the chosen index's indexed exprs.
        IOptimizableFuncExpr optFuncExpr = analysisCtx.getMatchedFuncExpr(exprIndex.first);
        int keyPos = indexOf(optFuncExpr.getFieldName(0), chosenIndex.getKeyFieldNames());
        if (keyPos < 0 && optFuncExpr.getNumLogicalVars() > 1) {
            // If we are optimizing a join, the matching field may be the second field name.
            keyPos = indexOf(optFuncExpr.getFieldName(1), chosenIndex.getKeyFieldNames());
        }
        if (keyPos < 0) {
            throw CompilationException.create(ErrorCode.NO_INDEX_FIELD_NAME_FOR_GIVEN_FUNC_EXPR);
        }
        Pair<ILogicalExpression, Boolean> returnedSearchKeyExpr = AccessMethodUtils.createSearchKeyExpr(optFuncExpr, indexSubTree, probeSubTree);
        ILogicalExpression searchKeyExpr = returnedSearchKeyExpr.first;
        if (searchKeyExpr.getExpressionTag() == LogicalExpressionTag.FUNCTION_CALL) {
            constantAtRuntimeExpressions[keyPos] = searchKeyExpr;
            constAtRuntimeExprVars[keyPos] = context.newVar();
            searchKeyExpr = new VariableReferenceExpression(constAtRuntimeExprVars[keyPos]);
        }
        realTypeConvertedToIntegerType = returnedSearchKeyExpr.second;
        LimitType limit = getLimitType(optFuncExpr, probeSubTree);
        //
        if (realTypeConvertedToIntegerType) {
            if (limit == LimitType.HIGH_EXCLUSIVE) {
                limit = LimitType.HIGH_INCLUSIVE;
            } else if (limit == LimitType.LOW_EXCLUSIVE) {
                limit = LimitType.LOW_INCLUSIVE;
            }
        }
        switch(limit) {
            case EQUAL:
                {
                    if (lowKeyLimits[keyPos] == null && highKeyLimits[keyPos] == null) {
                        lowKeyLimits[keyPos] = highKeyLimits[keyPos] = limit;
                        lowKeyInclusive[keyPos] = highKeyInclusive[keyPos] = true;
                        lowKeyExprs[keyPos] = highKeyExprs[keyPos] = searchKeyExpr;
                        setLowKeys.set(keyPos);
                        setHighKeys.set(keyPos);
                        isEqCondition = true;
                    } else {
                        // (once from analyzing each side of the join)
                        if (lowKeyLimits[keyPos] == limit && lowKeyInclusive[keyPos] == true && lowKeyExprs[keyPos].equals(searchKeyExpr) && highKeyLimits[keyPos] == limit && highKeyInclusive[keyPos] == true && highKeyExprs[keyPos].equals(searchKeyExpr)) {
                            isEqCondition = true;
                            break;
                        }
                        couldntFigureOut = true;
                    }
                    // If high and low keys are set, we exit for now.
                    if (setLowKeys.cardinality() == numSecondaryKeys && setHighKeys.cardinality() == numSecondaryKeys) {
                        doneWithExprs = true;
                    }
                    break;
                }
            case HIGH_EXCLUSIVE:
                {
                    if (highKeyLimits[keyPos] == null || (highKeyLimits[keyPos] != null && highKeyInclusive[keyPos])) {
                        highKeyLimits[keyPos] = limit;
                        highKeyExprs[keyPos] = searchKeyExpr;
                        highKeyInclusive[keyPos] = false;
                    } else {
                        // (once from analyzing each side of the join)
                        if (highKeyLimits[keyPos] == limit && highKeyInclusive[keyPos] == false && highKeyExprs[keyPos].equals(searchKeyExpr)) {
                            break;
                        }
                        couldntFigureOut = true;
                        doneWithExprs = true;
                    }
                    break;
                }
            case HIGH_INCLUSIVE:
                {
                    if (highKeyLimits[keyPos] == null) {
                        highKeyLimits[keyPos] = limit;
                        highKeyExprs[keyPos] = searchKeyExpr;
                        highKeyInclusive[keyPos] = true;
                    } else {
                        // (once from analyzing each side of the join)
                        if (highKeyLimits[keyPos] == limit && highKeyInclusive[keyPos] == true && highKeyExprs[keyPos].equals(searchKeyExpr)) {
                            break;
                        }
                        couldntFigureOut = true;
                        doneWithExprs = true;
                    }
                    break;
                }
            case LOW_EXCLUSIVE:
                {
                    if (lowKeyLimits[keyPos] == null || (lowKeyLimits[keyPos] != null && lowKeyInclusive[keyPos])) {
                        lowKeyLimits[keyPos] = limit;
                        lowKeyExprs[keyPos] = searchKeyExpr;
                        lowKeyInclusive[keyPos] = false;
                    } else {
                        // (once from analyzing each side of the join)
                        if (lowKeyLimits[keyPos] == limit && lowKeyInclusive[keyPos] == false && lowKeyExprs[keyPos].equals(searchKeyExpr)) {
                            break;
                        }
                        couldntFigureOut = true;
                        doneWithExprs = true;
                    }
                    break;
                }
            case LOW_INCLUSIVE:
                {
                    if (lowKeyLimits[keyPos] == null) {
                        lowKeyLimits[keyPos] = limit;
                        lowKeyExprs[keyPos] = searchKeyExpr;
                        lowKeyInclusive[keyPos] = true;
                    } else {
                        // (once from analyzing each side of the join)
                        if (lowKeyLimits[keyPos] == limit && lowKeyInclusive[keyPos] == true && lowKeyExprs[keyPos].equals(searchKeyExpr)) {
                            break;
                        }
                        couldntFigureOut = true;
                        doneWithExprs = true;
                    }
                    break;
                }
            default:
                {
                    throw new IllegalStateException();
                }
        }
        if (!couldntFigureOut) {
            // Remember to remove this funcExpr later.
            replacedFuncExprs.add(analysisCtx.getMatchedFuncExpr(exprIndex.first).getFuncExpr());
        }
        if (doneWithExprs) {
            break;
        }
    }
    if (couldntFigureOut) {
        return null;
    }
    // If the select condition contains mixed open/closed intervals on multiple keys, then we make all intervals
    // closed to obtain a superset of answers and leave the original selection in place.
    boolean primaryIndexPostProccessingIsNeeded = false;
    for (int i = 1; i < numSecondaryKeys; ++i) {
        if (lowKeyInclusive[i] != lowKeyInclusive[0]) {
            Arrays.fill(lowKeyInclusive, true);
            primaryIndexPostProccessingIsNeeded = true;
            break;
        }
    }
    for (int i = 1; i < numSecondaryKeys; ++i) {
        if (highKeyInclusive[i] != highKeyInclusive[0]) {
            Arrays.fill(highKeyInclusive, true);
            primaryIndexPostProccessingIsNeeded = true;
            break;
        }
    }
    // determine cases when prefix search could be applied
    for (int i = 1; i < lowKeyExprs.length; i++) {
        if (lowKeyLimits[0] == null && lowKeyLimits[i] != null || lowKeyLimits[0] != null && lowKeyLimits[i] == null || highKeyLimits[0] == null && highKeyLimits[i] != null || highKeyLimits[0] != null && highKeyLimits[i] == null) {
            numSecondaryKeys--;
            primaryIndexPostProccessingIsNeeded = true;
        }
    }
    if (lowKeyLimits[0] == null) {
        lowKeyInclusive[0] = true;
    }
    if (highKeyLimits[0] == null) {
        highKeyInclusive[0] = true;
    }
    // Here we generate vars and funcs for assigning the secondary-index keys to be fed into the secondary-index
    // search.
    // List of variables for the assign.
    ArrayList<LogicalVariable> keyVarList = new ArrayList<>();
    // List of variables and expressions for the assign.
    ArrayList<LogicalVariable> assignKeyVarList = new ArrayList<>();
    ArrayList<Mutable<ILogicalExpression>> assignKeyExprList = new ArrayList<>();
    int numLowKeys = createKeyVarsAndExprs(numSecondaryKeys, lowKeyLimits, lowKeyExprs, assignKeyVarList, assignKeyExprList, keyVarList, context, constantAtRuntimeExpressions, constAtRuntimeExprVars);
    int numHighKeys = createKeyVarsAndExprs(numSecondaryKeys, highKeyLimits, highKeyExprs, assignKeyVarList, assignKeyExprList, keyVarList, context, constantAtRuntimeExpressions, constAtRuntimeExprVars);
    BTreeJobGenParams jobGenParams = new BTreeJobGenParams(chosenIndex.getIndexName(), IndexType.BTREE, dataset.getDataverseName(), dataset.getDatasetName(), retainInput, requiresBroadcast);
    jobGenParams.setLowKeyInclusive(lowKeyInclusive[0]);
    jobGenParams.setHighKeyInclusive(highKeyInclusive[0]);
    jobGenParams.setIsEqCondition(isEqCondition);
    jobGenParams.setLowKeyVarList(keyVarList, 0, numLowKeys);
    jobGenParams.setHighKeyVarList(keyVarList, numLowKeys, numHighKeys);
    ILogicalOperator inputOp = null;
    if (!assignKeyVarList.isEmpty()) {
        // Assign operator that sets the constant secondary-index search-key fields if necessary.
        AssignOperator assignConstantSearchKeys = new AssignOperator(assignKeyVarList, assignKeyExprList);
        // Input to this assign is the EmptyTupleSource (which the dataSourceScan also must have had as input).
        assignConstantSearchKeys.getInputs().add(new MutableObject<>(OperatorManipulationUtil.deepCopy(dataSourceOp.getInputs().get(0).getValue())));
        assignConstantSearchKeys.setExecutionMode(dataSourceOp.getExecutionMode());
        inputOp = assignConstantSearchKeys;
    } else if (probeSubTree == null) {
        //nonpure case
        //Make sure that the nonpure function is unpartitioned
        ILogicalOperator checkOp = dataSourceOp.getInputs().get(0).getValue();
        while (checkOp.getExecutionMode() != ExecutionMode.UNPARTITIONED) {
            if (checkOp.getInputs().size() == 1) {
                checkOp = checkOp.getInputs().get(0).getValue();
            } else {
                return null;
            }
        }
        inputOp = dataSourceOp.getInputs().get(0).getValue();
    } else {
        // All index search keys are variables.
        inputOp = probeSubTree.getRoot();
    }
    ILogicalOperator secondaryIndexUnnestOp = AccessMethodUtils.createSecondaryIndexUnnestMap(dataset, recordType, metaRecordType, chosenIndex, inputOp, jobGenParams, context, false, retainInput, retainNull);
    // Generate the rest of the upstream plan which feeds the search results into the primary index.
    AbstractUnnestMapOperator primaryIndexUnnestOp = null;
    boolean isPrimaryIndex = chosenIndex.isPrimaryIndex();
    if (dataset.getDatasetType() == DatasetType.EXTERNAL) {
        // External dataset
        UnnestMapOperator externalDataAccessOp = AccessMethodUtils.createExternalDataLookupUnnestMap(dataSourceOp, dataset, recordType, secondaryIndexUnnestOp, context, retainInput, retainNull);
        indexSubTree.getDataSourceRef().setValue(externalDataAccessOp);
        return externalDataAccessOp;
    } else if (!isPrimaryIndex) {
        primaryIndexUnnestOp = AccessMethodUtils.createPrimaryIndexUnnestMap(dataSourceOp, dataset, recordType, metaRecordType, secondaryIndexUnnestOp, context, true, retainInput, retainNull, false);
        // Adds equivalence classes --- one equivalent class between a primary key
        // variable and a record field-access expression.
        EquivalenceClassUtils.addEquivalenceClassesForPrimaryIndexAccess(primaryIndexUnnestOp, dataSourceOp.getVariables(), recordType, metaRecordType, dataset, context);
    } else {
        List<Object> primaryIndexOutputTypes = new ArrayList<>();
        AccessMethodUtils.appendPrimaryIndexTypes(dataset, recordType, metaRecordType, primaryIndexOutputTypes);
        List<LogicalVariable> scanVariables = dataSourceOp.getVariables();
        // If not, we create a new condition based on remaining ones.
        if (!primaryIndexPostProccessingIsNeeded) {
            List<Mutable<ILogicalExpression>> remainingFuncExprs = new ArrayList<>();
            try {
                getNewConditionExprs(conditionRef, replacedFuncExprs, remainingFuncExprs);
            } catch (CompilationException e) {
                return null;
            }
            // Generate new condition.
            if (!remainingFuncExprs.isEmpty()) {
                ILogicalExpression pulledCond = createSelectCondition(remainingFuncExprs);
                conditionRef.setValue(pulledCond);
            } else {
                conditionRef.setValue(null);
            }
        }
        // Checks whether LEFT_OUTER_UNNESTMAP operator is required.
        boolean leftOuterUnnestMapRequired = false;
        if (retainNull && retainInput) {
            leftOuterUnnestMapRequired = true;
        } else {
            leftOuterUnnestMapRequired = false;
        }
        if (conditionRef.getValue() != null) {
            // The job gen parameters are transferred to the actual job gen
            // via the UnnestMapOperator's function arguments.
            List<Mutable<ILogicalExpression>> primaryIndexFuncArgs = new ArrayList<>();
            jobGenParams.writeToFuncArgs(primaryIndexFuncArgs);
            // An index search is expressed as an unnest-map over an
            // index-search function.
            IFunctionInfo primaryIndexSearch = FunctionUtil.getFunctionInfo(BuiltinFunctions.INDEX_SEARCH);
            UnnestingFunctionCallExpression primaryIndexSearchFunc = new UnnestingFunctionCallExpression(primaryIndexSearch, primaryIndexFuncArgs);
            primaryIndexSearchFunc.setReturnsUniqueValues(true);
            if (!leftOuterUnnestMapRequired) {
                primaryIndexUnnestOp = new UnnestMapOperator(scanVariables, new MutableObject<ILogicalExpression>(primaryIndexSearchFunc), primaryIndexOutputTypes, retainInput);
            } else {
                primaryIndexUnnestOp = new LeftOuterUnnestMapOperator(scanVariables, new MutableObject<ILogicalExpression>(primaryIndexSearchFunc), primaryIndexOutputTypes, true);
            }
        } else {
            if (!leftOuterUnnestMapRequired) {
                primaryIndexUnnestOp = new UnnestMapOperator(scanVariables, ((UnnestMapOperator) secondaryIndexUnnestOp).getExpressionRef(), primaryIndexOutputTypes, retainInput);
            } else {
                primaryIndexUnnestOp = new LeftOuterUnnestMapOperator(scanVariables, ((LeftOuterUnnestMapOperator) secondaryIndexUnnestOp).getExpressionRef(), primaryIndexOutputTypes, true);
            }
        }
        primaryIndexUnnestOp.getInputs().add(new MutableObject<>(inputOp));
        // Adds equivalence classes --- one equivalent class between a primary key
        // variable and a record field-access expression.
        EquivalenceClassUtils.addEquivalenceClassesForPrimaryIndexAccess(primaryIndexUnnestOp, scanVariables, recordType, metaRecordType, dataset, context);
    }
    return primaryIndexUnnestOp;
}