private long getTimestampVal(IndexSearchCondition sc) throws IOException {
long timestamp;
try {
ExprNodeConstantEvaluator eval = new ExprNodeConstantEvaluator(sc.getConstantDesc());
ObjectInspector inspector = eval.initialize(null);
Object value = eval.evaluate(null);
if (inspector instanceof LongObjectInspector) {
timestamp = ((LongObjectInspector)inspector).get(value);
} else {
PrimitiveObjectInspector primitive = (PrimitiveObjectInspector) inspector;
timestamp = PrimitiveObjectInspectorUtils.getTimestamp(value, primitive).getTime();