Github user zellerh commented on a diff in the pull request:
https://github.com/apache/trafodion/pull/1658#discussion_r206719109
--- Diff: core/sql/generator/GenPreCode.cpp ---
@@ -7518,6 +7518,53 @@ ItemExpr * AggrMinMax::preCodeGen(Generator *
generator)
return this;
} // AggrMinMax::preCodeGen()
+ItemExpr *Overlaps::preCodeGen(Generator *generator)
+{
+ if (nodeIsPreCodeGenned())
+ return getReplacementExpr();
+
+ for (Int32 i = 0; i < getArity(); ++i)
+ {
+ if (child(i))
+ {
+ const NAType &type =
+ child(i)->getValueId().getType();
+ const DatetimeType *operand = (DatetimeType *)&type;
+
+ if (type.getTypeQualifier() == NA_DATETIME_TYPE
+ && (operand->getPrecision() == SQLDTCODE_DATE))
+ {
+ child(i) = new (generator->wHeap())
+ Cast(child(i), new (generator->wHeap())
+ SQLTimestamp(generator->wHeap(), TRUE));
+
+ child(i)->bindNode(generator->getBindWA());
+ }
+
+ }
+ }
+
+ ItemExpr *newExpr =
+ generator->getExpGenerator()->createExprTree(
--- End diff --
When I look at the ANSI/ISO standard, it has some cases where the OVERLAPS
predicate returns TRUE, even though some of the values are NULL. Example:
```(date '2000-01-01', date '2000-01-03') overlaps (date '2000-01-02',
cast(null as date))``` should return TRUE, as far as I understand the General
Rules:
- S1: 1-01
- T1: 1-03
- S2: 1-02
- T2: null
So, the predicate ```S2 > S1 and not ( S2 >= T1 and T2 >= T1 )``` becomes
``` 2 > 1 and not ( 2 >= 3 and null >= 3)``` which is TRUE.
I don't think the formula below would ever return TRUE if any of the 4
arguments were NULL.
---
