private void analyzeCall(RexCall call, Constancy callConstancy) { parentCallTypeStack.add(call.getOperator()); // visit operands, pushing their states onto stack super.visitCall(call); // look for NON_CONSTANT operands int nOperands = call.getOperands().length; List<Constancy> operandStack = stack.subList(stack.size() - nOperands, stack.size()); for (Constancy operandConstancy : operandStack) { if (operandConstancy == Constancy.NON_CONSTANT) { callConstancy = Constancy.NON_CONSTANT; } } // Even if all operands are constant, the call itself may // be non-deterministic. if (!call.getOperator().isDeterministic()) { callConstancy = Constancy.NON_CONSTANT; } else if (call.getOperator().isDynamicFunction()) { // We can reduce the call to a constant, but we can't // cache the plan if the function is dynamic preparingStmt.disableStatementCaching(); } // Row operator itself can't be reduced to a literal, but if // the operands are constants, we still want to reduce those if ((callConstancy == Constancy.REDUCIBLE_CONSTANT) && (call.getOperator() instanceof SqlRowOperator)) { callConstancy = Constancy.NON_CONSTANT; } if (callConstancy == Constancy.NON_CONSTANT) { // any REDUCIBLE_CONSTANT children are now known to be maximal // reducible subtrees, so they can be added to the result // list for (int iOperand = 0; iOperand < nOperands; ++iOperand) { Constancy constancy = operandStack.get(iOperand); if (constancy == Constancy.REDUCIBLE_CONSTANT) { addResult(call.getOperands()[iOperand]); } } // if this cast expression can't be reduced to a literal, // then see if we can remove the cast if (call.getOperator() == SqlStdOperatorTable.castFunc) { reduceCasts(call); } } // pop operands off of the stack operandStack.clear(); // pop this parent call operator off the stack parentCallTypeStack.remove(parentCallTypeStack.size() - 1); // push constancy result for this call onto stack stack.add(callConstancy); }
/** * Creates an OR expression from a list of RexNodes * * @param rexList list of RexNodes * @return OR'd expression */ public static RexNode orRexNodeList(RexBuilder rexBuilder, List<RexNode> rexList) { if (rexList.isEmpty()) { return null; } RexNode orExpr = rexList.get(rexList.size() - 1); for (int i = rexList.size() - 2; i >= 0; i--) { orExpr = rexBuilder.makeCall(SqlStdOperatorTable.orOperator, rexList.get(i), orExpr); } return orExpr; }
/** * Locates expressions that can be reduced to literals or converted to expressions with redundant * casts removed. * * @param preparingStmt the statement containing the expressions * @param exps list of candidate expressions to be examined for reduction * @param constExps returns the list of expressions that can be constant reduced * @param addCasts indicator for each expression that can be constant reduced, whether a cast of * the resulting reduced expression is potentially necessary * @param removableCasts returns the list of cast expressions where the cast can be removed */ private static void findReducibleExps( FarragoSessionPreparingStmt preparingStmt, List<RexNode> exps, List<RexNode> constExps, List<Boolean> addCasts, List<RexNode> removableCasts) { ReducibleExprLocator gardener = new ReducibleExprLocator(preparingStmt, constExps, addCasts, removableCasts); for (RexNode exp : exps) { gardener.analyze(exp); } assert (constExps.size() == addCasts.size()); }
/** * Creates an AND expression from a list of RexNodes * * @param rexList list of RexNodes * @return AND'd expression */ public static RexNode andRexNodeList(RexBuilder rexBuilder, List<RexNode> rexList) { if (rexList.isEmpty()) { return null; } // create a right-deep tree to allow short-circuiting during // expression evaluation RexNode andExpr = rexList.get(rexList.size() - 1); for (int i = rexList.size() - 2; i >= 0; i--) { andExpr = rexBuilder.makeCall(SqlStdOperatorTable.andOperator, rexList.get(i), andExpr); } return andExpr; }
/** * Resolves a multi-part identifier such as "SCHEMA.EMP.EMPNO" to a namespace. The returned * namespace may represent a schema, table, column, etc. * * @pre names.size() > 0 * @post return != null */ public static SqlValidatorNamespace lookup(SqlValidatorScope scope, List<String> names) { Util.pre(names.size() > 0, "names.size() > 0"); SqlValidatorNamespace namespace = null; for (int i = 0; i < names.size(); i++) { String name = names.get(i); if (i == 0) { namespace = scope.resolve(name, null, null); } else { namespace = namespace.lookupChild(name); } } Util.permAssert(namespace != null, "post: namespace != null"); return namespace; }
/** * Returns a relational expression which has the same fields as the underlying expression, but the * fields have different names. * * @param rel Relational expression * @param fieldNames Field names * @return Renamed relational expression */ public static RelNode createRename(RelNode rel, List<String> fieldNames) { final List<RelDataTypeField> fields = rel.getRowType().getFieldList(); assert fieldNames.size() == fields.size(); final List<Pair<RexNode, String>> refs = new AbstractList<Pair<RexNode, String>>() { public int size() { return fields.size(); } public Pair<RexNode, String> get(int index) { return RexInputRef.of2(index, fields); } }; return createProject(rel, refs, true); }
public void onMatch(RelOptRuleCall call) { assert matches(call); final JoinRel join = (JoinRel) call.rels[0]; final List<Integer> leftKeys = new ArrayList<Integer>(); final List<Integer> rightKeys = new ArrayList<Integer>(); RelNode right = join.getRight(); final RelNode left = join.getLeft(); RexNode remainingCondition = RelOptUtil.splitJoinCondition(left, right, join.getCondition(), leftKeys, rightKeys); assert leftKeys.size() == rightKeys.size(); final List<CorrelatorRel.Correlation> correlationList = new ArrayList<CorrelatorRel.Correlation>(); if (leftKeys.size() > 0) { final RelOptCluster cluster = join.getCluster(); final RexBuilder rexBuilder = cluster.getRexBuilder(); int k = 0; RexNode condition = null; for (Integer leftKey : leftKeys) { Integer rightKey = rightKeys.get(k++); final String dyn_inIdStr = cluster.getQuery().createCorrel(); final int dyn_inId = RelOptQuery.getCorrelOrdinal(dyn_inIdStr); // Create correlation to say 'each row, set variable #id // to the value of column #leftKey'. correlationList.add(new CorrelatorRel.Correlation(dyn_inId, leftKey)); condition = RelOptUtil.andJoinFilters( rexBuilder, condition, rexBuilder.makeCall( SqlStdOperatorTable.equalsOperator, rexBuilder.makeInputRef( right.getRowType().getFieldList().get(rightKey).getType(), rightKey), rexBuilder.makeCorrel( left.getRowType().getFieldList().get(leftKey).getType(), dyn_inIdStr))); } right = CalcRel.createFilter(right, condition); } RelNode newRel = new CorrelatorRel( join.getCluster(), left, right, remainingCondition, correlationList, join.getJoinType()); call.transformTo(newRel); }
public RelOptTable getTableForMember(List<String> names) { final SqlValidatorTable table = catalogReader.getTable(names); final RelDataType rowType = table.getRowType(); final List<RelCollation> collationList = deduceMonotonicity(table); if (names.size() < 3) { String[] newNames2 = {"CATALOG", "SALES", ""}; List<String> newNames = new ArrayList<String>(); int i = 0; while (newNames.size() < newNames2.length) { newNames.add(i, newNames2[i]); ++i; } names = newNames; } return createColumnSet(table, names, rowType, collationList); }
private void addResult(RexNode exp) { // Cast of literal can't be reduced, so skip those (otherwise we'd // go into an infinite loop as we add them back). if (exp.getKind() == RexKind.Cast) { RexCall cast = (RexCall) exp; RexNode operand = cast.getOperands()[0]; if (operand instanceof RexLiteral) { return; } } constExprs.add(exp); // In the case where the expression corresponds to a UDR argument, // we need to preserve casts. Note that this only applies to // the topmost argument, not expressions nested within the UDR // call. // // REVIEW zfong 6/13/08 - Are there other expressions where we // also need to preserve casts? if (parentCallTypeStack.isEmpty()) { addCasts.add(false); } else { addCasts.add( parentCallTypeStack.get(parentCallTypeStack.size() - 1) instanceof FarragoUserDefinedRoutine); } }
public void onMatch(RelOptRuleCall call) { CalcRel calc = (CalcRel) call.getRels()[0]; RexProgram program = calc.getProgram(); final List<RexNode> exprList = program.getExprList(); // Form a list of expressions with sub-expressions fully // expanded. final List<RexNode> expandedExprList = new ArrayList<RexNode>(exprList.size()); final RexShuttle shuttle = new RexShuttle() { public RexNode visitLocalRef(RexLocalRef localRef) { return expandedExprList.get(localRef.getIndex()); } }; for (RexNode expr : exprList) { expandedExprList.add(expr.accept(shuttle)); } if (reduceExpressions(calc, expandedExprList)) { final RexProgramBuilder builder = new RexProgramBuilder( calc.getChild().getRowType(), calc.getCluster().getRexBuilder()); List<RexLocalRef> list = new ArrayList<RexLocalRef>(); for (RexNode expr : expandedExprList) { list.add(builder.registerInput(expr)); } if (program.getCondition() != null) { final int conditionIndex = program.getCondition().getIndex(); final RexNode newConditionExp = expandedExprList.get(conditionIndex); if (newConditionExp.isAlwaysTrue()) { // condition is always TRUE - drop it } else if ((newConditionExp instanceof RexLiteral) || RexUtil.isNullLiteral(newConditionExp, true)) { // condition is always NULL or FALSE - replace calc // with empty call.transformTo(new EmptyRel(calc.getCluster(), calc.getRowType())); return; } else { builder.addCondition(list.get(conditionIndex)); } } int k = 0; for (RexLocalRef projectExpr : program.getProjectList()) { final int index = projectExpr.getIndex(); builder.addProject( list.get(index).getIndex(), program.getOutputRowType().getFieldList().get(k++).getName()); } call.transformTo( new CalcRel( calc.getCluster(), calc.getTraits(), calc.getChild(), calc.getRowType(), builder.getProgram(), calc.getCollationList())); // New plan is absolutely better than old plan. call.getPlanner().setImportance(calc, 0.0); } }
/** * Applies a visitor to a list of expressions and, if specified, a single expression. * * @param visitor Visitor * @param exprs List of expressions * @param expr Single expression, may be null */ public static void apply(RexVisitor<Void> visitor, List<? extends RexNode> exprs, RexNode expr) { for (int i = 0; i < exprs.size(); i++) { exprs.get(i).accept(visitor); } if (expr != null) { expr.accept(visitor); } }
/** * Applies a mapping to a list. * * @param mapping Mapping * @param list List * @param <T> Element type * @return List with elements permuted according to mapping */ public static <T> List<T> apply(final Mapping mapping, final List<T> list) { if (mapping.getSourceCount() != list.size()) { // REVIEW: too strict? throw new IllegalArgumentException( "mapping source count " + mapping.getSourceCount() + " does not match list size " + list.size()); } final int targetCount = mapping.getTargetCount(); final List<T> list2 = new ArrayList<T>(targetCount); for (int target = 0; target < targetCount; ++target) { final int source = mapping.getSource(target); list2.add(list.get(source)); } return list2; }
/** * Creates a partial mapping from a list. For example, <code> * PartialMapping({1, 2, 4}, 6)</code> creates the mapping * * <table border="1"> * <caption>Example</caption> * <tr> * <th>source</th> * <td>0</td> * <td>1</td> * <td>2</td> * <td>3</td> * <td>4</td> * <td>5</td> * </tr> * <tr> * <th>target</th> * <td>-1</td> * <td>0</td> * <td>1</td> * <td>-1</td> * <td>2</td> * <td>-1</td> * </tr> * </table> * * @param sourceList List whose i'th element is the source of target #i * @param sourceCount Number of elements in the source domain * @param mappingType Mapping type, must be {@link * org.eigenbase.util.mapping.MappingType#PARTIAL_SURJECTION} or stronger. */ public PartialMapping(List<Integer> sourceList, int sourceCount, MappingType mappingType) { this.mappingType = mappingType; assert mappingType.isSingleSource(); assert mappingType.isSingleTarget(); int targetCount = sourceList.size(); this.targets = new int[sourceCount]; this.sources = new int[targetCount]; Arrays.fill(sources, -1); for (int i = 0; i < sourceList.size(); ++i) { final int source = sourceList.get(i); sources[i] = source; if (source >= 0) { targets[source] = i; } else { assert !this.mappingType.isMandatorySource(); } } }
/** * Applies a mapping to a list of field collations. * * @param mapping Mapping * @param fieldCollations Field collations * @return collations with mapping applied */ public static List<RelFieldCollation> apply( Mapping mapping, List<RelFieldCollation> fieldCollations) { final List<RelFieldCollation> newFieldCollations = new ArrayList<RelFieldCollation>(fieldCollations.size()); for (RelFieldCollation fieldCollation : fieldCollations) { newFieldCollations.add(apply(mapping, fieldCollation)); } return newFieldCollations; }
public static Mapping target(List<Integer> sources, int sourceCount) { final int targetCount = sources.size(); final PartialFunctionImpl mapping = new PartialFunctionImpl(sourceCount, targetCount, MappingType.FUNCTION); for (int target = 0; target < targetCount; target++) { int source = sources.get(target); mapping.set(source, target); } return mapping; }
public static Mapping source(List<Integer> targets, int targetCount) { final int sourceCount = targets.size(); final PartialFunctionImpl mapping = new PartialFunctionImpl(sourceCount, targetCount, MappingType.FUNCTION); for (int source = 0; source < sourceCount; source++) { int target = targets.get(source); mapping.set(source, target); } return mapping; }
/** Returns whether a list of integers is the identity mapping [0, ..., n - 1]. */ public static boolean isIdentity(List<Integer> list, int count) { if (list.size() != count) { return false; } for (int i = 0; i < count; i++) { final Integer o = list.get(i); if (o == null || o != i) { return false; } } return true; }
/** * Creates a relational expression which projects the output fields of a relational expression * according to a partial mapping. * * <p>A partial mapping is weaker than a permutation: every target has one source, but a source * may have 0, 1 or more than one targets. Usually the result will have fewer fields than the * source, unless some source fields are projected multiple times. * * <p>This method could optimize the result as {@link #permute} does, but does not at present. * * @param rel Relational expression * @param mapping Mapping from source fields to target fields. The mapping type must obey the * constaints {@link MappingType#isMandatorySource()} and {@link * MappingType#isSingleSource()}, as does {@link MappingType#InverseFunction}. * @param fieldNames Field names; if null, or if a particular entry is null, the name of the * permuted field is used * @return relational expression which projects a subset of the input fields */ public static RelNode projectMapping(RelNode rel, Mapping mapping, List<String> fieldNames) { assert mapping.getMappingType().isSingleSource(); assert mapping.getMappingType().isMandatorySource(); if (mapping.isIdentity()) { return rel; } final List<RelDataType> outputTypeList = new ArrayList<RelDataType>(); final List<String> outputNameList = new ArrayList<String>(); final List<RexNode> exprList = new ArrayList<RexNode>(); final List<RexLocalRef> projectRefList = new ArrayList<RexLocalRef>(); final List<RelDataTypeField> fields = rel.getRowType().getFieldList(); for (int i = 0; i < fields.size(); i++) { final RelDataTypeField field = fields.get(i); exprList.add(rel.getCluster().getRexBuilder().makeInputRef(field.getType(), i)); } for (int i = 0; i < mapping.getTargetCount(); i++) { int source = mapping.getSource(i); final RelDataTypeField sourceField = fields.get(source); outputTypeList.add(sourceField.getType()); outputNameList.add( ((fieldNames == null) || (fieldNames.size() <= i) || (fieldNames.get(i) == null)) ? sourceField.getName() : fieldNames.get(i)); projectRefList.add(new RexLocalRef(source, sourceField.getType())); } final RexProgram program = new RexProgram( rel.getRowType(), exprList, projectRefList, null, rel.getCluster().getTypeFactory().createStructType(outputTypeList, outputNameList)); return new CalcRel( rel.getCluster(), rel.getTraitSet(), rel, program.getOutputRowType(), program, Collections.<RelCollation>emptyList()); }
/** * Creates a relational expression which permutes the output fields of a relational expression * according to a permutation. * * <p>Optimizations: * * <ul> * <li>If the relational expression is a {@link CalcRel} or {@link ProjectRel} which is already * acting as a permutation, combines the new permutation with the old; * <li>If the permutation is the identity, returns the original relational expression. * </ul> * * <p>If a permutation is combined with its inverse, these optimizations would combine to remove * them both. * * @param rel Relational expression * @param permutation Permutation to apply to fields * @param fieldNames Field names; if null, or if a particular entry is null, the name of the * permuted field is used * @return relational expression which permutes its input fields */ public static RelNode permute(RelNode rel, Permutation permutation, List<String> fieldNames) { if (permutation.isIdentity()) { return rel; } if (rel instanceof CalcRel) { CalcRel calcRel = (CalcRel) rel; Permutation permutation1 = calcRel.getProgram().getPermutation(); if (permutation1 != null) { Permutation permutation2 = permutation.product(permutation1); return permute(rel, permutation2, null); } } if (rel instanceof ProjectRel) { Permutation permutation1 = ((ProjectRel) rel).getPermutation(); if (permutation1 != null) { Permutation permutation2 = permutation.product(permutation1); return permute(rel, permutation2, null); } } final List<RelDataType> outputTypeList = new ArrayList<RelDataType>(); final List<String> outputNameList = new ArrayList<String>(); final List<RexNode> exprList = new ArrayList<RexNode>(); final List<RexLocalRef> projectRefList = new ArrayList<RexLocalRef>(); final List<RelDataTypeField> fields = rel.getRowType().getFieldList(); for (int i = 0; i < permutation.getTargetCount(); i++) { int target = permutation.getTarget(i); final RelDataTypeField targetField = fields.get(target); outputTypeList.add(targetField.getType()); outputNameList.add( ((fieldNames == null) || (fieldNames.size() <= i) || (fieldNames.get(i) == null)) ? targetField.getName() : fieldNames.get(i)); exprList.add(rel.getCluster().getRexBuilder().makeInputRef(fields.get(i).getType(), i)); final int source = permutation.getSource(i); projectRefList.add(new RexLocalRef(source, fields.get(source).getType())); } final RexProgram program = new RexProgram( rel.getRowType(), exprList, projectRefList, null, rel.getCluster().getTypeFactory().createStructType(outputTypeList, outputNameList)); return new CalcRel( rel.getCluster(), rel.getTraitSet(), rel, program.getOutputRowType(), program, Collections.<RelCollation>emptyList()); }
/** * Trims a child relational expression, then adds back a dummy project to restore the fields that * were removed. * * <p>Sounds pointless? It causes unused fields to be removed further down the tree (towards the * leaves), but it ensure that the consuming relational expression continues to see the same * fields. * * @param rel Relational expression * @param input Input relational expression, whose fields to trim * @param fieldsUsed Bitmap of fields needed by the consumer * @return New relational expression and its field mapping */ protected TrimResult trimChildRestore( RelNode rel, RelNode input, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) { TrimResult trimResult = trimChild(rel, input, fieldsUsed, extraFields); if (trimResult.right.isIdentity()) { return trimResult; } final RelDataType rowType = input.getRowType(); List<RelDataTypeField> fieldList = rowType.getFieldList(); final List<RexNode> exprList = new ArrayList<RexNode>(); final List<String> nameList = rowType.getFieldNames(); RexBuilder rexBuilder = rel.getCluster().getRexBuilder(); assert trimResult.right.getSourceCount() == fieldList.size(); for (int i = 0; i < fieldList.size(); i++) { int source = trimResult.right.getTargetOpt(i); RelDataTypeField field = fieldList.get(i); exprList.add( source < 0 ? rexBuilder.makeZeroLiteral(field.getType()) : rexBuilder.makeInputRef(field.getType(), source)); } RelNode project = CalcRel.createProject(trimResult.left, exprList, nameList); return new TrimResult(project, Mappings.createIdentity(fieldList.size())); }
public void analyze(RexNode exp) { assert (stack.isEmpty()); exp.accept(this); // Deal with top of stack assert (stack.size() == 1); assert (parentCallTypeStack.isEmpty()); Constancy rootConstancy = stack.get(0); if (rootConstancy == Constancy.REDUCIBLE_CONSTANT) { // The entire subtree was constant, so add it to the result. addResult(exp); } stack.clear(); }
public static RelDataType createTypeFromProjection( RelDataType type, List<String> columnNameList, RelDataTypeFactory typeFactory, boolean caseSensitive) { // If the names in columnNameList and type have case-sensitive differences, // the resulting type will use those from type. These are presumably more // canonical. final List<RelDataTypeField> fields = new ArrayList<RelDataTypeField>(columnNameList.size()); for (String name : columnNameList) { RelDataTypeField field = type.getField(name, caseSensitive); fields.add(type.getFieldList().get(field.getIndex())); } return typeFactory.createStructType(fields); }
public static void getSchemaObjectMonikers( SqlValidatorCatalogReader catalogReader, List<String> names, List<SqlMoniker> hints) { // Assume that the last name is 'dummy' or similar. List<String> subNames = Util.skipLast(names); hints.addAll(catalogReader.getAllSchemaObjectNames(subNames)); // If the name has length 0, try prepending the name of the default // schema. So, the empty name would yield a list of tables in the // default schema, as well as a list of schemas from the above code. if (subNames.size() == 0) { hints.addAll( catalogReader.getAllSchemaObjectNames( Collections.singletonList(catalogReader.getSchemaName()))); } }
public void onMatch(RelOptRuleCall call) { ProjectRel project = (ProjectRel) call.rels[0]; List<RexNode> expList = new ArrayList<RexNode>(Arrays.asList(project.getChildExps())); if (reduceExpressions(project, expList)) { call.transformTo( new ProjectRel( project.getCluster(), project.getChild(), expList.toArray(new RexNode[expList.size()]), project.getRowType(), ProjectRel.Flags.Boxed, Collections.<RelCollation>emptyList())); // New plan is absolutely better than old plan. call.getPlanner().setImportance(project, 0.0); } }
// implement SargExpr public SargIntervalSequence evaluate() { if (setOp == SargSetOperator.COMPLEMENT) { assert (children.size() == 1); SargExpr child = children.get(0); return child.evaluateComplemented(); } List<SargIntervalSequence> list = evaluateChildren(this); switch (setOp) { case UNION: return evaluateUnion(list); case INTERSECTION: return evaluateIntersection(list); default: throw Util.newInternal(setOp.toString()); } }
public void onMatch(RelOptRuleCall call) { FilterRel filter = (FilterRel) call.rels[0]; List<RexNode> expList = new ArrayList<RexNode>(Arrays.asList(filter.getChildExps())); RexNode newConditionExp; boolean reduced; if (reduceExpressions(filter, expList)) { assert (expList.size() == 1); newConditionExp = expList.get(0); reduced = true; } else { // No reduction, but let's still test the original // predicate to see if it was already a constant, // in which case we don't need any runtime decision // about filtering. newConditionExp = filter.getChildExps()[0]; reduced = false; } if (newConditionExp.isAlwaysTrue()) { call.transformTo(filter.getChild()); } else if ((newConditionExp instanceof RexLiteral) || RexUtil.isNullLiteral(newConditionExp, true)) { call.transformTo(new EmptyRel(filter.getCluster(), filter.getRowType())); } else if (reduced) { call.transformTo(CalcRel.createFilter(filter.getChild(), expList.get(0))); } else { if (newConditionExp instanceof RexCall) { RexCall rexCall = (RexCall) newConditionExp; boolean reverse = (rexCall.getOperator() == SqlStdOperatorTable.notOperator); if (reverse) { rexCall = (RexCall) rexCall.getOperands()[0]; } reduceNotNullableFilter(call, filter, rexCall, reverse); } return; } // New plan is absolutely better than old plan. call.getPlanner().setImportance(filter, 0.0); }
protected void explain_(RelNode rel, List<Pair<String, Object>> values) { final Map<String, Object> map = jsonBuilder.map(); map.put("id", null); // ensure that id is the first attribute map.put("relOp", relJson.classToTypeName(rel.getClass())); for (Pair<String, Object> value : values) { if (value.right instanceof RelNode) { continue; } put(map, value.left, value.right); } // omit 'inputs: ["3"]' if "3" is the preceding rel final List<Object> list = explainInputs(rel.getInputs()); if (list.size() != 1 || !list.get(0).equals(previousId)) { map.put("inputs", list); } final String id = Integer.toString(relIdMap.size()); relIdMap.put(rel, id); map.put("id", id); relList.add(map); previousId = id; }
/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link ProjectRel}. */ public TrimResult trimFields( ProjectRel project, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) { final RelDataType rowType = project.getRowType(); final int fieldCount = rowType.getFieldCount(); final RelNode input = project.getChild(); final RelDataType inputRowType = input.getRowType(); // Which fields are required from the input? BitSet inputFieldsUsed = new BitSet(inputRowType.getFieldCount()); final Set<RelDataTypeField> inputExtraFields = new LinkedHashSet<RelDataTypeField>(extraFields); RelOptUtil.InputFinder inputFinder = new RelOptUtil.InputFinder(inputFieldsUsed, inputExtraFields); for (Ord<RexNode> ord : Ord.zip(project.getProjects())) { if (fieldsUsed.get(ord.i)) { ord.e.accept(inputFinder); } } // Create input with trimmed columns. TrimResult trimResult = trimChild(project, input, inputFieldsUsed, inputExtraFields); RelNode newInput = trimResult.left; final Mapping inputMapping = trimResult.right; // If the input is unchanged, and we need to project all columns, // there's nothing we can do. if (newInput == input && fieldsUsed.cardinality() == fieldCount) { return new TrimResult(project, Mappings.createIdentity(fieldCount)); } // Some parts of the system can't handle rows with zero fields, so // pretend that one field is used. if (fieldsUsed.cardinality() == 0) { final Mapping mapping = Mappings.create(MappingType.InverseSurjection, fieldCount, 1); final RexLiteral expr = project.getCluster().getRexBuilder().makeExactLiteral(BigDecimal.ZERO); RelDataType newRowType = project .getCluster() .getTypeFactory() .createStructType( Collections.singletonList(expr.getType()), Collections.singletonList("DUMMY")); ProjectRel newProject = new ProjectRel( project.getCluster(), project.getCluster().traitSetOf(RelCollationImpl.EMPTY), newInput, Collections.<RexNode>singletonList(expr), newRowType, project.getFlags()); return new TrimResult(newProject, mapping); } // Build new project expressions, and populate the mapping. List<RexNode> newProjectExprList = new ArrayList<RexNode>(); final RexVisitor<RexNode> shuttle = new RexPermuteInputsShuttle(inputMapping, newInput); final Mapping mapping = Mappings.create(MappingType.InverseSurjection, fieldCount, fieldsUsed.cardinality()); for (Ord<RexNode> ord : Ord.zip(project.getProjects())) { if (fieldsUsed.get(ord.i)) { mapping.set(ord.i, newProjectExprList.size()); RexNode newProjectExpr = ord.e.accept(shuttle); newProjectExprList.add(newProjectExpr); } } final RelDataType newRowType = project .getCluster() .getTypeFactory() .createStructType(Mappings.apply3(mapping, rowType.getFieldList())); final List<RelCollation> newCollations = RexUtil.apply(inputMapping, project.getCollationList()); final RelNode newProject; if (RemoveTrivialProjectRule.isIdentity( newProjectExprList, newRowType, newInput.getRowType())) { // The new project would be the identity. It is equivalent to return // its child. newProject = newInput; } else { newProject = new ProjectRel( project.getCluster(), project .getCluster() .traitSetOf( newCollations.isEmpty() ? RelCollationImpl.EMPTY : newCollations.get(0)), newInput, newProjectExprList, newRowType, project.getFlags()); assert newProject.getClass() == project.getClass(); } return new TrimResult(newProject, mapping); }
/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link JoinRel}. */ public TrimResult trimFields(JoinRel join, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) { final RelDataType rowType = join.getRowType(); final int fieldCount = rowType.getFieldCount(); final RexNode conditionExpr = join.getCondition(); final int systemFieldCount = join.getSystemFieldList().size(); // Add in fields used in the condition. BitSet fieldsUsedPlus = (BitSet) fieldsUsed.clone(); final Set<RelDataTypeField> combinedInputExtraFields = new LinkedHashSet<RelDataTypeField>(extraFields); RelOptUtil.InputFinder inputFinder = new RelOptUtil.InputFinder(fieldsUsedPlus, combinedInputExtraFields); conditionExpr.accept(inputFinder); // If no system fields are used, we can remove them. int systemFieldUsedCount = 0; for (int i = 0; i < systemFieldCount; ++i) { if (fieldsUsed.get(i)) { ++systemFieldUsedCount; } } final int newSystemFieldCount; if (systemFieldUsedCount == 0) { newSystemFieldCount = 0; } else { newSystemFieldCount = systemFieldCount; } int offset = systemFieldCount; int changeCount = 0; int newFieldCount = newSystemFieldCount; List<RelNode> newInputs = new ArrayList<RelNode>(2); List<Mapping> inputMappings = new ArrayList<Mapping>(); List<Integer> inputExtraFieldCounts = new ArrayList<Integer>(); for (RelNode input : join.getInputs()) { final RelDataType inputRowType = input.getRowType(); final int inputFieldCount = inputRowType.getFieldCount(); // Compute required mapping. BitSet inputFieldsUsed = new BitSet(inputFieldCount); for (int bit : Util.toIter(fieldsUsedPlus)) { if (bit >= offset && bit < offset + inputFieldCount) { inputFieldsUsed.set(bit - offset); } } // If there are system fields, we automatically use the // corresponding field in each input. if (newSystemFieldCount > 0) { // calling with newSystemFieldCount == 0 should be safe but hits // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6222207 inputFieldsUsed.set(0, newSystemFieldCount); } // FIXME: We ought to collect extra fields for each input // individually. For now, we assume that just one input has // on-demand fields. Set<RelDataTypeField> inputExtraFields = input.getRowType().getField("_extra") == null ? Collections.<RelDataTypeField>emptySet() : combinedInputExtraFields; inputExtraFieldCounts.add(inputExtraFields.size()); TrimResult trimResult = trimChild(join, input, inputFieldsUsed, inputExtraFields); newInputs.add(trimResult.left); if (trimResult.left != input) { ++changeCount; } final Mapping inputMapping = trimResult.right; inputMappings.add(inputMapping); // Move offset to point to start of next input. offset += inputFieldCount; newFieldCount += inputMapping.getTargetCount() + inputExtraFields.size(); } Mapping mapping = Mappings.create(MappingType.InverseSurjection, fieldCount, newFieldCount); for (int i = 0; i < newSystemFieldCount; ++i) { mapping.set(i, i); } offset = systemFieldCount; int newOffset = newSystemFieldCount; for (int i = 0; i < inputMappings.size(); i++) { Mapping inputMapping = inputMappings.get(i); for (IntPair pair : inputMapping) { mapping.set(pair.source + offset, pair.target + newOffset); } offset += inputMapping.getSourceCount(); newOffset += inputMapping.getTargetCount() + inputExtraFieldCounts.get(i); } if (changeCount == 0 && mapping.isIdentity()) { return new TrimResult(join, Mappings.createIdentity(fieldCount)); } // Build new join. final RexVisitor<RexNode> shuttle = new RexPermuteInputsShuttle(mapping, newInputs.get(0), newInputs.get(1)); RexNode newConditionExpr = conditionExpr.accept(shuttle); final JoinRel newJoin = join.copy(join.getTraitSet(), newConditionExpr, newInputs.get(0), newInputs.get(1)); return new TrimResult(newJoin, mapping); }
/** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link AggregateRel}. */ public TrimResult trimFields( AggregateRel aggregate, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) { // Fields: // // | sys fields | group fields | agg functions | // // Two kinds of trimming: // // 1. If agg rel has system fields but none of these are used, create an // agg rel with no system fields. // // 2. If aggregate functions are not used, remove them. // // But grouping fields stay, even if they are not used. final RelDataType rowType = aggregate.getRowType(); // Compute which input fields are used. BitSet inputFieldsUsed = new BitSet(); // 1. group fields are always used for (int i : Util.toIter(aggregate.getGroupSet())) { inputFieldsUsed.set(i); } // 2. agg functions for (AggregateCall aggCall : aggregate.getAggCallList()) { for (int i : aggCall.getArgList()) { inputFieldsUsed.set(i); } } // Create input with trimmed columns. final RelNode input = aggregate.getInput(0); final Set<RelDataTypeField> inputExtraFields = Collections.emptySet(); final TrimResult trimResult = trimChild(aggregate, input, inputFieldsUsed, inputExtraFields); final RelNode newInput = trimResult.left; final Mapping inputMapping = trimResult.right; // If the input is unchanged, and we need to project all columns, // there's nothing to do. if (input == newInput && fieldsUsed.equals(Util.bitSetBetween(0, rowType.getFieldCount()))) { return new TrimResult(aggregate, Mappings.createIdentity(rowType.getFieldCount())); } // Which agg calls are used by our consumer? final int groupCount = aggregate.getGroupSet().cardinality(); int j = groupCount; int usedAggCallCount = 0; for (int i = 0; i < aggregate.getAggCallList().size(); i++) { if (fieldsUsed.get(j++)) { ++usedAggCallCount; } } // Offset due to the number of system fields having changed. Mapping mapping = Mappings.create( MappingType.InverseSurjection, rowType.getFieldCount(), groupCount + usedAggCallCount); final BitSet newGroupSet = Mappings.apply(inputMapping, aggregate.getGroupSet()); // Populate mapping of where to find the fields. System and grouping // fields first. for (IntPair pair : inputMapping) { if (pair.source < groupCount) { mapping.set(pair.source, pair.target); } } // Now create new agg calls, and populate mapping for them. final List<AggregateCall> newAggCallList = new ArrayList<AggregateCall>(); j = groupCount; for (AggregateCall aggCall : aggregate.getAggCallList()) { if (fieldsUsed.get(j)) { AggregateCall newAggCall = new AggregateCall( aggCall.getAggregation(), aggCall.isDistinct(), Mappings.apply2(inputMapping, aggCall.getArgList()), aggCall.getType(), aggCall.getName()); if (newAggCall.equals(aggCall)) { newAggCall = aggCall; // immutable -> canonize to save space } mapping.set(j, groupCount + newAggCallList.size()); newAggCallList.add(newAggCall); } ++j; } RelNode newAggregate = new AggregateRel(aggregate.getCluster(), newInput, newGroupSet, newAggCallList); assert newAggregate.getClass() == aggregate.getClass(); return new TrimResult(newAggregate, mapping); }