Github user DaveBirdsall commented on a diff in the pull request:
https://github.com/apache/trafodion/pull/1622#discussion_r199651226
--- Diff: core/sql/optimizer/SynthType.cpp ---
@@ -4470,15 +4489,31 @@ const NAType *Extract::synthesizeType()
else if (getExtractField() == REC_DATE_YEARWEEK_EXTRACT ||
getExtractField() == REC_DATE_YEARWEEK_D_EXTRACT)
prec = 6; // YEARMWEEK is yyyyww
+ else if (getExtractField() == REC_DATE_DECADE ||
+ getExtractField() == REC_DATE_DOY)
+ prec = 3;
+ else if (getExtractField() == REC_DATE_QUARTER ||
+ getExtractField() == REC_DATE_DOW)
+ prec = 1;
+ else if (getExtractField() == REC_DATE_EPOCH)
+ prec = 10;
else
prec = 2; // else max of 12, 31,
24, 59
if (getExtractField() == REC_DATE_SECOND) {
prec += dti.getFractionPrecision();
scale += dti.getFractionPrecision();
}
+ if (getExtractField() == REC_DATE_EPOCH)
+ {
+ prec += dti.getFractionPrecision();
+ scale += dti.getFractionPrecision();
+ }
+ NABoolean bNegValue = FALSE;
+ if ( getExtractField() >= REC_DATE_CENTURY && extractStartField <=
REC_DATE_WOM )
+ bNegValue = TRUE;
--- End diff --
I'm confused. From this code, it looks like all of the new options can
yield negative values. Yet, earlier, for example, QUARTER is limited to a
precision of 1. I could imagine QUARTER being negative if it were with respect
to the first quarter of year 1 AD. But since the precision is 1, I'm guessing
that QUARTER is always with respect to the current year, so it only takes the
values 1, 2, 3 or 4. I'm wondering what DECADE, DOM, DOY and WOM are; what are
they relative to? And can they be negative?
---
