/**
* 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;
}
}
private void reduceNotNullableFilter(
RelOptRuleCall call, FilterRel filter, RexCall rexCall, boolean reverse) {
// If the expression is a IS [NOT] NULL on a non-nullable
// column, then we can either remove the filter or replace
// it with an EmptyRel.
SqlOperator op = rexCall.getOperator();
boolean alwaysTrue;
if (op == SqlStdOperatorTable.isNullOperator
|| op == SqlStdOperatorTable.isUnknownOperator) {
alwaysTrue = false;
} else if (op == SqlStdOperatorTable.isNotNullOperator) {
alwaysTrue = true;
} else {
return;
}
if (reverse) {
alwaysTrue = !alwaysTrue;
}
RexNode operand = rexCall.getOperands()[0];
if (operand instanceof RexInputRef) {
RexInputRef inputRef = (RexInputRef) operand;
if (!inputRef.getType().isNullable()) {
if (alwaysTrue) {
call.transformTo(filter.getChild());
} else {
call.transformTo(new EmptyRel(filter.getCluster(), filter.getRowType()));
}
}
}
}
public Void visitInputRef(RexInputRef inputRef) {
super.visitInputRef(inputRef);
if (inputRef.getIndex() >= inputRowType.getFieldCount()) {
throw new IllegalForwardRefException();
}
return null;
}
/**
* Returns whether the leading edge of a given array of expressions is wholly {@link RexInputRef}
* objects with types corresponding to the underlying datatype.
*/
public static boolean containIdentity(RexNode[] exprs, RelDataType rowType, boolean fail) {
final RelDataTypeField[] fields = rowType.getFields();
if (exprs.length < fields.length) {
assert !fail : "exprs/rowType length mismatch";
return false;
}
for (int i = 0; i < fields.length; i++) {
if (!(exprs[i] instanceof RexInputRef)) {
assert !fail : "expr[" + i + "] is not a RexInputRef";
return false;
}
RexInputRef inputRef = (RexInputRef) exprs[i];
if (inputRef.getIndex() != i) {
assert !fail : "expr[" + i + "] has ordinal " + inputRef.getIndex();
return false;
}
if (!RelOptUtil.eq("type1", exprs[i].getType(), "type2", fields[i].getType(), fail)) {
return false;
}
}
return true;
}
public JavaRel findRel(JavaRel rel, RexNode expression) {
if (expression instanceof RexInputRef) {
RexInputRef variable = (RexInputRef) expression;
// REVIEW jvs 30-May-2005: What's up with this? The "&& false"
// should have at least a comment!
if ((rel instanceof JoinRelBase) && false) {
return (JavaRel) findInputRel(rel, variable.getIndex());
} else {
return (JavaRel) rel.getInput(variable.getIndex());
}
} else if (expression instanceof RexFieldAccess) {
RexFieldAccess fieldAccess = (RexFieldAccess) expression;
String fieldName = fieldAccess.getName();
RexNode refExp = fieldAccess.getReferenceExpr();
JavaRel rel2 = findRel(rel, refExp); // recursive
if (rel2 == null) {
return null;
}
return implementFieldAccess(rel2, fieldName);
} else {
return null;
}
}
public Void visitInputRef(RexInputRef inputRef) {
refCounts[inputRef.getIndex()]++;
return null;
}
protected Integer mapFieldRef(RexNode exp, List<String> origFieldName, RelDataType rowType) {
RexInputRef fieldAccess = (RexInputRef) exp;
origFieldName.add(rowType.getFields()[fieldAccess.getIndex()].getName());
return fieldAccess.getIndex();
}
