private CompareTupleFilter mergeToInClause(TupleFilter filter) {
List<? extends TupleFilter> children = filter.getChildren();
TblColRef inColumn = null;
List<String> inValues = new LinkedList<String>();
for (TupleFilter child : children) {
if (child.getOperator() == FilterOperatorEnum.EQ) {
CompareTupleFilter compFilter = (CompareTupleFilter) child;
TblColRef column = compFilter.getColumn();
if (inColumn == null) {
inColumn = column;
}
if (column == null || !column.equals(inColumn)) {
return null;
}
inValues.addAll(compFilter.getValues());
} else {
return null;
}
}
children.clear();
CompareTupleFilter inFilter = new CompareTupleFilter(FilterOperatorEnum.IN);
inFilter.addChild(new ColumnTupleFilter(inColumn));
inFilter.addChild(new ConstantTupleFilter(inValues));
return inFilter;
}
private void collectColumnsRecursively(TupleFilter filter, Set<TblColRef> collector) {
if (filter instanceof ColumnTupleFilter) {
collector.add(((ColumnTupleFilter) filter).getColumn());
}
for (TupleFilter child : filter.getChildren()) {
collectColumnsRecursively(child, collector);
}
}
