@Override
public Datum eval(Tuple params) {
Datum datum = params.get(0);
if (datum instanceof NullDatum) return NullDatum.get();
return DatumFactory.createInt4(datum.asByteArray().length * 8);
}
/**
* It computes the value cardinality of a tuple range.
*
* @param dataType
* @param start
* @param end
* @return
*/
public static BigDecimal computeCardinality(
DataType dataType, Datum start, Datum end, boolean inclusive) {
BigDecimal columnCard;
switch (dataType.getType()) {
case BOOLEAN:
columnCard = new BigDecimal(2);
break;
case CHAR:
columnCard = new BigDecimal(end.asChar() - start.asChar());
break;
case BIT:
columnCard = new BigDecimal(end.asByte() - start.asByte());
break;
case INT2:
columnCard = new BigDecimal(end.asInt2() - start.asInt2());
break;
case INT4:
columnCard = new BigDecimal(end.asInt4() - start.asInt4());
break;
case INT8:
columnCard = new BigDecimal(end.asInt8() - start.asInt8());
break;
case FLOAT4:
columnCard = new BigDecimal(end.asInt4() - start.asInt4());
break;
case FLOAT8:
columnCard = new BigDecimal(end.asInt8() - start.asInt8());
break;
case TEXT:
columnCard = new BigDecimal(end.asChars().charAt(0) - start.asChars().charAt(0));
break;
case DATE:
columnCard = new BigDecimal(end.asInt4() - start.asInt4());
break;
case TIME:
case TIMESTAMP:
columnCard = new BigDecimal(end.asInt8() - start.asInt8());
break;
default:
throw new UnsupportedOperationException(dataType + " is not supported yet");
}
return inclusive ? columnCard.add(new BigDecimal(1)) : columnCard;
}
