@Override
public Object process(Node nd, Stack<Node> stack, NodeProcessorCtx ctx, Object... nodeOutputs)
throws SemanticException {
GroupByOperator op = (GroupByOperator) nd;
ColumnPrunerProcCtx cppCtx = (ColumnPrunerProcCtx) ctx;
List<String> colLists = new ArrayList<String>();
GroupByDesc conf = op.getConf();
ArrayList<ExprNodeDesc> keys = conf.getKeys();
for (ExprNodeDesc key : keys) {
colLists = Utilities.mergeUniqElems(colLists, key.getCols());
}
ArrayList<AggregationDesc> aggrs = conf.getAggregators();
for (AggregationDesc aggr : aggrs) {
ArrayList<ExprNodeDesc> params = aggr.getParameters();
for (ExprNodeDesc param : params) {
colLists = Utilities.mergeUniqElems(colLists, param.getCols());
}
}
int groupingSetPosition = conf.getGroupingSetPosition();
if (groupingSetPosition >= 0) {
List<String> cols = cppCtx.genColLists(op);
String groupingColumn = conf.getOutputColumnNames().get(groupingSetPosition);
if (!cols.contains(groupingColumn)) {
conf.getOutputColumnNames().remove(groupingSetPosition);
if (op.getSchema() != null) {
op.getSchema().getSignature().remove(groupingSetPosition);
}
}
}
cppCtx.getPrunedColLists().put(op, colLists);
return null;
}
