/**
* Analyzes a rex predicate.
*
* @param rexPredicate predicate to be analyzed
* @return a list of SargBindings contained in the input rex predicate
*/
public List<SargBinding> analyzeAll(RexNode rexPredicate) {
sargBindingList = new ArrayList<SargBinding>();
sarg2RexMap = new HashMap<SargExpr, RexNode>();
nonSargFilterList = new ArrayList<RexNode>();
// Flatten out the RexNode tree into a list of terms that
// are AND'ed together
final List<RexNode> rexCFList = RelOptUtil.conjunctions(rexPredicate);
// In simple mode, each input ref can only be referenced once, so
// keep a list of them. We also only allow one non-point expression.
List<Integer> boundRefList = new ArrayList<Integer>();
boolean rangeFound = false;
for (RexNode rexPred : rexCFList) {
final SargBinding sargBinding = analyze(rexPred);
if (sargBinding != null) {
if (simpleMode) {
RexInputRef inputRef = sargBinding.getInputRef();
if (boundRefList.contains(inputRef.getIndex())) {
nonSargFilterList.add(rexPred);
continue;
} else {
boundRefList.add(inputRef.getIndex());
}
SargIntervalSequence sargSeq = sargBinding.getExpr().evaluate();
if (sargSeq.isRange()) {
if (rangeFound) {
nonSargFilterList.add(rexPred);
continue;
} else {
rangeFound = true;
}
}
}
sargBindingList.add(sargBinding);
sarg2RexMap.put(sargBinding.getExpr(), rexPred);
} else {
nonSargFilterList.add(rexPred);
}
}
// Reset the state variables used during analyze, just for sanity sake.
failed = false;
boundInputRef = null;
clearLeaf();
// Combine the AND terms back together.
recomposeConjunction();
return sargBindingList;
}
/** Reconstructs a rex predicate from a list of SargExprs which will be AND'ed together. */
private void recomposeConjunction() {
for (int i = 0; i < sargBindingList.size(); i++) {
final SargBinding currBinding = sargBindingList.get(i);
final RexInputRef currRef = currBinding.getInputRef();
SargExpr currSargExpr = currBinding.getExpr();
RexNode currAndNode = sarg2RexMap.get(currSargExpr);
// don't need this anymore
// will be have new mapping put back if currSargExpr remain
// unchanged.
sarg2RexMap.remove(currSargExpr);
boolean recomp = false;
// search the rest of the list to find SargExpr on the same col.
ListIterator<SargBinding> iter = sargBindingList.listIterator(i + 1);
while (iter.hasNext()) {
final SargBinding nextBinding = iter.next();
final RexInputRef nextRef = nextBinding.getInputRef();
final SargExpr nextSargExpr = nextBinding.getExpr();
if (nextRef.getIndex() == currRef.getIndex()) {
// build new SargExpr
SargSetExpr expr =
factory.newSetExpr(currSargExpr.getDataType(), SargSetOperator.INTERSECTION);
expr.addChild(currSargExpr);
expr.addChild(nextSargExpr);
// build new RexNode
currAndNode =
factory
.getRexBuilder()
.makeCall(
SqlStdOperatorTable.andOperator, currAndNode, sarg2RexMap.get(nextSargExpr));
currSargExpr = expr;
sarg2RexMap.remove(nextSargExpr);
iter.remove();
recomp = true;
}
}
if (recomp) {
assert !simpleMode;
if (!testDynamicParamSupport(currSargExpr)) {
// Oops, we can't actually support the conjunction we
// recomposed. Toss it. (We could do a better job by at
// least using part of it, but the effort might be better
// spent on implementing deferred expression evaluation.)
nonSargFilterList.add(currAndNode);
sargBindingList.remove(i);
continue;
}
}
if (recomp) {
SargBinding newBinding = new SargBinding(currSargExpr, currRef);
sargBindingList.remove(i);
sargBindingList.add(i, newBinding);
}
sarg2RexMap.put(currSargExpr, currAndNode);
}
}
