macroguo-ghy commented on code in PR #3416:
URL: https://github.com/apache/calcite/pull/3416#discussion_r1327973848
##########
core/src/main/java/org/apache/calcite/rex/RexSimplify.java:
##########
@@ -2060,6 +2060,25 @@ private RexNode simplifyOrs(List<RexNode> terms,
RexUnknownAs unknownAs) {
}
}
break;
+ case IS_NOT_TRUE:
+ if (terms.contains(((RexCall) term).getOperands().get(0))) {
+ return trueLiteral;
+ }
+ break;
+ case NOT:
+ RexNode x = ((RexCall) term).getOperands().get(0);
+ if (terms.contains(x)) {
Review Comment:
Thanks for your explaination, I got your points.
For the first case `x or not(x)`, I add a new limitation where `x` must be
safeExpression.
But for the second case `a or x or not(x) or b`, I think we can simplify `x
or not(x)` no matter whether `a` and `b` safe or not.
Thinking about a simple case: `true or unSafeUdf()`, calcite will simplify
this expression to `true`. And I have tested `select * from t where 1/0 or
true` expression in mysql and sparksql, both of them will simpilfy this
expression to `true`. And third, in most of programing language (like Java,
C++, Python), they always simplify `true or someConditions` to `true` in if
clause (A little different, it is Short-circuit OR actully, but we check all
items).
So I think we don't need to care about outside items whether safe or not.
##########
core/src/main/java/org/apache/calcite/rex/RexSimplify.java:
##########
@@ -2060,6 +2060,25 @@ private RexNode simplifyOrs(List<RexNode> terms,
RexUnknownAs unknownAs) {
}
}
break;
+ case IS_NOT_TRUE:
+ if (terms.contains(((RexCall) term).getOperands().get(0))) {
+ return trueLiteral;
Review Comment:
Thanks for your explaination, I got your points.
For the first case `x or not(x)`, I add a new limitation where `x` must be
safeExpression.
But for the second case `a or x or not(x) or b`, I think we can simplify x
or not(x) no matter whether `a` and `b` safe or not.
Thinking about a simple case: `true or unSafeUdf()`, calcite will simplify
this expression to `true`. And I have tested `select * from t where 1/0 or
true` expression in mysql and sparksql, both of them will simpilfy this
expression to `true`. And third, in most of programing language(like Java, C++,
Python), they always simplify `true or someConditions` to `true` in if clause
(A little different, it is Short-circuit OR actully, but we check all items).
So I think we don't need to care about outside items whether safe or not.
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