@Override
public Void visitGroupByOperator(GroupByOperator op, Pair<LogicalVariable, LogicalVariable> pair)
throws AlgebricksException {
subst(pair.first, pair.second, op.getGroupByList());
subst(pair.first, pair.second, op.getDecorList());
for (ILogicalPlan p : op.getNestedPlans()) {
for (Mutable<ILogicalOperator> r : p.getRoots()) {
OperatorManipulationUtil.substituteVarRec(
(AbstractLogicalOperator) r.getValue(), pair.first, pair.second, goThroughNts, ctx);
}
}
substVarTypes(op, pair);
return null;
}
@Override
public Void visitGroupByOperator(GroupByOperator op, Void arg) throws AlgebricksException {
for (ILogicalPlan p : op.getNestedPlans()) {
for (Mutable<ILogicalOperator> r : p.getRoots()) {
VariableUtilities.getLiveVariables(r.getValue(), schemaVariables);
}
}
for (Pair<LogicalVariable, Mutable<ILogicalExpression>> p : op.getGroupByList()) {
if (p.first != null) {
schemaVariables.add(p.first);
}
}
for (Pair<LogicalVariable, Mutable<ILogicalExpression>> p : op.getDecorList()) {
if (p.first != null) {
schemaVariables.add(p.first);
} else {
ILogicalExpression e = p.second.getValue();
if (e.getExpressionTag() == LogicalExpressionTag.VARIABLE) {
schemaVariables.add(((VariableReferenceExpression) e).getVariableReference());
}
}
}
return null;
}
@Override
public boolean rewritePost(Mutable<ILogicalOperator> opRef, IOptimizationContext context) {
AbstractLogicalOperator op = (AbstractLogicalOperator) opRef.getValue();
if (op.getOperatorTag() != LogicalOperatorTag.GROUP) {
return false;
}
if (context.checkIfInDontApplySet(this, op)) {
return false;
}
vars.clear();
boolean modified = false;
GroupByOperator groupOp = (GroupByOperator) op;
Iterator<Pair<LogicalVariable, Mutable<ILogicalExpression>>> iter =
groupOp.getDecorList().iterator();
while (iter.hasNext()) {
Pair<LogicalVariable, Mutable<ILogicalExpression>> decor = iter.next();
if (decor.first != null
|| decor.second.getValue().getExpressionTag() != LogicalExpressionTag.VARIABLE) {
continue;
}
VariableReferenceExpression varRefExpr =
(VariableReferenceExpression) decor.second.getValue();
LogicalVariable var = varRefExpr.getVariableReference();
if (vars.contains(var)) {
iter.remove();
modified = true;
} else {
vars.add(var);
}
}
if (modified) {
context.addToDontApplySet(this, op);
}
return modified;
}