public static void setupNeededColumns(
TableScanOperator scanOp, RowResolver inputRR, List<String> cols) throws SemanticException {
List<Integer> neededColumnIds = new ArrayList<Integer>();
List<String> neededColumnNames = new ArrayList<String>();
List<String> referencedColumnNames = new ArrayList<String>();
TableScanDesc desc = scanOp.getConf();
List<VirtualColumn> virtualCols = desc.getVirtualCols();
List<VirtualColumn> newVirtualCols = new ArrayList<VirtualColumn>();
// add virtual columns for ANALYZE TABLE
if (scanOp.getConf().isGatherStats()) {
cols.add(VirtualColumn.RAWDATASIZE.getName());
}
for (String column : cols) {
String[] tabCol = inputRR.reverseLookup(column);
if (tabCol == null) {
continue;
}
referencedColumnNames.add(column);
ColumnInfo colInfo = inputRR.get(tabCol[0], tabCol[1]);
if (colInfo.getIsVirtualCol()) {
// part is also a virtual column, but part col should not in this
// list.
for (int j = 0; j < virtualCols.size(); j++) {
VirtualColumn vc = virtualCols.get(j);
if (vc.getName().equals(colInfo.getInternalName())) {
newVirtualCols.add(vc);
}
}
// no need to pass virtual columns to reader.
continue;
}
int position = inputRR.getPosition(column);
if (position >= 0) {
// get the needed columns by id and name
neededColumnIds.add(position);
neededColumnNames.add(column);
}
}
desc.setVirtualCols(newVirtualCols);
scanOp.setNeededColumnIDs(neededColumnIds);
scanOp.setNeededColumns(neededColumnNames);
scanOp.setReferencedColumns(referencedColumnNames);
}
