xuzifu666 commented on code in PR #5178:
URL: https://github.com/apache/calcite/pull/5178#discussion_r3784572596
##########
core/src/main/java/org/apache/calcite/adapter/enumerable/RexImpTable.java:
##########
@@ -2491,12 +2490,84 @@ protected FirstLastValueImplementor(SeekType seekType) {
AggResultContext result) {
WinAggResultContext winResult = (WinAggResultContext) result;
+ final boolean ignoreNulls =
+ info instanceof WinAggContext && ((WinAggContext)
info).ignoreNulls();
+ if (ignoreNulls) {
+ return implementResultIgnoreNulls(info, winResult);
+ }
+
return Expressions.condition(winResult.hasRows(),
winResult.rowTranslator(
winResult.computeIndex(Expressions.constant(0), seekType))
.translate(winResult.rexArguments().get(0), info.returnType()),
getDefaultValue(info.returnType()));
}
+
+ /**
+ * Implements FIRST_VALUE / LAST_VALUE with IGNORE NULLS by scanning the
+ * frame (forward for FIRST_VALUE, backward for LAST_VALUE) and returning
+ * the first non-null argument value, or the default value if all rows in
Review Comment:
You're right, the default value is always null here. I changed the Javadoc
from "or the default value if all rows..." to "or null if all rows..." to be
explicit.
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