// implement RelOptRule
public void onMatch(RelOptRuleCall call) {
CalcRel calcRel = (CalcRel) call.rels[0];
RexProgram program = calcRel.getProgram();
// check the projection
List<Integer> projOrdinals = new ArrayList<Integer>();
RelDataType outputRowType = isProjectSimple(calcRel, projOrdinals);
if (outputRowType == null) {
return;
}
RexLocalRef condition = program.getCondition();
CompOperatorEnum compOp = CompOperatorEnum.COMP_NOOP;
Integer[] filterOrdinals = {};
List<RexLiteral> filterLiterals = new ArrayList<RexLiteral>();
// check the condition
if (condition != null) {
RexNode filterExprs = program.expandLocalRef(condition);
List<Integer> filterList = new ArrayList<Integer>();
List<CompOperatorEnum> op = new ArrayList<CompOperatorEnum>();
if (!isConditionSimple(calcRel, filterExprs, filterList, filterLiterals, op)) {
return;
}
compOp = op.get(0);
filterOrdinals = filterList.toArray(new Integer[filterList.size()]);
}
RelNode fennelInput =
mergeTraitsAndConvert(
calcRel.getTraits(), FennelRel.FENNEL_EXEC_CONVENTION, calcRel.getChild());
if (fennelInput == null) {
return;
}
Integer[] projection = projOrdinals.toArray(new Integer[projOrdinals.size()]);
FennelReshapeRel reshapeRel =
new FennelReshapeRel(
calcRel.getCluster(),
fennelInput,
projection,
outputRowType,
compOp,
filterOrdinals,
filterLiterals,
new FennelRelParamId[] {},
new Integer[] {},
null);
call.transformTo(reshapeRel);
}
/**
* 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());
}
/**
* Determines if a filter condition is a simple one and returns the parameters corresponding to
* the simple filters.
*
* @param calcRel original CalcRel
* @param filterExprs filter expression being analyzed
* @param filterList returns the list of filter ordinals in the simple expression
* @param literals returns the list of literals to be used in the simple comparisons
* @param op returns the operator to be used in the simple comparison
* @return true if the filter condition is simple
*/
private boolean isConditionSimple(
CalcRel calcRel,
RexNode filterExprs,
List<Integer> filterList,
List<RexLiteral> literals,
List<CompOperatorEnum> op) {
SargFactory sargFactory = new SargFactory(calcRel.getCluster().getRexBuilder());
SargRexAnalyzer rexAnalyzer = sargFactory.newRexAnalyzer(true);
List<SargBinding> sargBindingList = rexAnalyzer.analyzeAll(filterExprs);
// Currently, it's all or nothing. So, if there are filters rejected
// by the analyzer, we can't process a subset using the reshape
// exec stream
if (rexAnalyzer.getNonSargFilterRexNode() != null) {
return false;
}
List<RexInputRef> filterCols = new ArrayList<RexInputRef>();
List<RexNode> filterOperands = new ArrayList<RexNode>();
if (FennelRelUtil.extractSimplePredicates(sargBindingList, filterCols, filterOperands, op)) {
for (RexInputRef filterCol : filterCols) {
filterList.add(filterCol.getIndex());
}
for (RexNode operand : filterOperands) {
literals.add((RexLiteral) operand);
}
return true;
} else {
return false;
}
}
/**
* Determines if a projection is simple.
*
* @param calcRel CalcRel containing the projection
* @param projOrdinals if the projection is simple, returns the ordinals of the projection inputs
* @return rowtype corresponding to the projection, provided it is simple; otherwise null is
* returned
*/
private RelDataType isProjectSimple(CalcRel calcRel, List<Integer> projOrdinals) {
// Loop through projection expressions. If we find a non-simple
// projection expression, simply return.
RexProgram program = calcRel.getProgram();
List<RexLocalRef> projList = program.getProjectList();
int nProjExprs = projList.size();
RelDataType[] types = new RelDataType[nProjExprs];
String[] fieldNames = new String[nProjExprs];
RelDataTypeField[] projFields = calcRel.getRowType().getFields();
for (int i = 0; i < nProjExprs; i++) {
RexNode projExpr = program.expandLocalRef(projList.get(i));
if (projExpr instanceof RexInputRef) {
projOrdinals.add(((RexInputRef) projExpr).getIndex());
types[i] = projExpr.getType();
fieldNames[i] = projFields[i].getName();
continue;
} else if (!(projExpr instanceof RexCall)) {
return null;
}
RexCall rexCall = (RexCall) projExpr;
if (rexCall.getOperator() != SqlStdOperatorTable.castFunc) {
return null;
}
RexNode castOperand = rexCall.getOperands()[0];
if (!(castOperand instanceof RexInputRef)) {
return null;
}
RelDataType castType = projExpr.getType();
RelDataType origType = castOperand.getType();
if (isCastSimple(origType, castType)) {
projOrdinals.add(((RexInputRef) castOperand).getIndex());
types[i] = castType;
fieldNames[i] = projFields[i].getName();
} else {
return null;
}
}
// return the rowtype corresponding to the output of the projection
return calcRel.getCluster().getTypeFactory().createStructType(types, fieldNames);
}
/**
* Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link SetOpRel} (including UNION and
* UNION ALL).
*/
public TrimResult trimFields(
SetOpRel setOp, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
final RelDataType rowType = setOp.getRowType();
final int fieldCount = rowType.getFieldCount();
int changeCount = 0;
// Fennel abhors an empty row type, so pretend that the parent rel
// wants the last field. (The last field is the least likely to be a
// system field.)
if (fieldsUsed.isEmpty()) {
fieldsUsed.set(rowType.getFieldCount() - 1);
}
// Compute the desired field mapping. Give the consumer the fields they
// want, in the order that they appear in the bitset.
final Mapping mapping = createMapping(fieldsUsed, fieldCount);
// Create input with trimmed columns.
final List<RelNode> newInputs = new ArrayList<RelNode>();
for (RelNode input : setOp.getInputs()) {
TrimResult trimResult = trimChild(setOp, input, fieldsUsed, extraFields);
RelNode newInput = trimResult.left;
final Mapping inputMapping = trimResult.right;
// We want "mapping", the input gave us "inputMapping", compute
// "remaining" mapping.
// | | |
// |---------------- mapping ---------->|
// |-- inputMapping -->| |
// | |-- remaining -->|
//
// For instance, suppose we have columns [a, b, c, d],
// the consumer asked for mapping = [b, d],
// and the transformed input has columns inputMapping = [d, a, b].
// remaining will permute [b, d] to [d, a, b].
Mapping remaining = Mappings.divide(mapping, inputMapping);
// Create a projection; does nothing if remaining is identity.
newInput = CalcRel.projectMapping(newInput, remaining, null);
if (input != newInput) {
++changeCount;
}
newInputs.add(newInput);
}
// If the input is unchanged, and we need to project all columns,
// there's to do.
if (changeCount == 0 && mapping.isIdentity()) {
return new TrimResult(setOp, mapping);
}
RelNode newSetOp = setOp.copy(setOp.getTraitSet(), newInputs);
return new TrimResult(newSetOp, mapping);
}
public static RelNode createProject(final RelNode child, final List<Integer> posList) {
return CalcRel.createProject(
child,
new AbstractList<RexNode>() {
public int size() {
return posList.size();
}
public RexNode get(int index) {
final int pos = posList.get(index);
return child
.getCluster()
.getRexBuilder()
.makeInputRef(child.getRowType().getFieldList().get(pos).getType(), pos);
}
},
null);
}
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);
}
/**
* 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()));
}
/**
* Creates new RelNodes replacing/removing the original project/row scan
*
* @param projectedScan new scan that is now projected
* @param origProject original projection
* @param needRename true if fields from the row scan need to be renamed
* @param newProject projection that contains the new projection expressions, in the case where
* the original projection cannot be removed because it projects expressions
* @return new RelNode
*/
public RelNode createNewRelNode(
RelNode projectedScan, ProjectRel origProject, boolean needRename, ProjectRel newProject) {
RelNode scanRel;
if (needRename) {
// Replace calling convention with FENNEL_EXEC_CONVENTION
RelTraitSet traits = RelOptUtil.clone(origProject.getTraits());
traits.setTrait(CallingConventionTraitDef.instance, FennelRel.FENNEL_EXEC_CONVENTION);
if (!traits.equals(projectedScan.getTraits())) {
RelNode mergedProjectedScan = convert(projectedScan, traits);
RelOptPlanner planner = projectedScan.getCluster().getPlanner();
// register projectedScan == mergedProjectedScan
// so mergedProjectedScan will have a set later on
projectedScan = planner.ensureRegistered(mergedProjectedScan, projectedScan);
}
scanRel =
new FennelRenameRel(
origProject.getCluster(),
projectedScan,
RelOptUtil.getFieldNames(origProject.getRowType()),
traits);
} else {
scanRel = projectedScan;
}
if (newProject == null) {
return scanRel;
} else {
// in the case where the projection had expressions, put the
// new, modified projection on top of the projected row scan
return (ProjectRel)
CalcRel.createProject(
scanRel,
newProject.getProjectExps(),
RelOptUtil.getFieldNames(newProject.getRowType()));
}
}
protected void executeImpl() throws Exception {
RelNode oneRowRel = new OneRowRel(getPreparingStmt().getRelOptCluster());
RelNode projectRel = CalcRel.createProject(oneRowRel, exprs, null);
executePlan(projectRel, exprs, false, true);
}
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);
}
}