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https://issues.apache.org/jira/browse/CALCITE-2455?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16577727#comment-16577727
]
Julian Hyde commented on CALCITE-2455:
--------------------------------------
[~danny0405], Maybe you need to make sure the email address for your github
account matches the email address for your commits. Currently when I go to
[https://github.com/apache/calcite/pull/782/commits] github doesn't think that
yuzhao.cyz is a github user. Compare to
[https://github.com/apache/calcite/pull/779/commits], for example, where
"snuyanzin" links to
[https://github.com/apache/calcite/commits?author=snuyanzin].
I agree with [~vlsi] that {{simplify}} should be allowed to strengthen the
type. If people want to keep the same type, they should call
{{simplifyPreservingType}} (the javadoc incorrectly says that it is only for
boolean expressions).
{{simplifyCase}} is wrong to try to keep the same type. I just needed to patch
{{ReduceExpressionsRule}} to make everything work:
{noformat}
diff --git
a/core/src/main/java/org/apache/calcite/rel/rules/ReduceExpressionsRule.java
b/core/src/main/java/org/apache/calcite/rel/rules/ReduceExpressionsRule.java
index a3ae9d91f..821a623e1 100644
--- a/core/src/main/java/org/apache/calcite/rel/rules/ReduceExpressionsRule.java
+++ b/core/src/main/java/org/apache/calcite/rel/rules/ReduceExpressionsRule.java
@@ -788,7 +788,7 @@ protected static RexNode substitute(RexCall call, int
ordinal, RexNode node) {
}
node = super.visitCall(call);
if (node != call) {
- node = simplify.withUnknownAsFalse(false).simplify(node);
+ node = simplify.withUnknownAsFalse(false).simplifyPreservingType(node);
}
return node;
}
diff --git a/core/src/main/java/org/apache/calcite/rex/RexSimplify.java
b/core/src/main/java/org/apache/calcite/rex/RexSimplify.java
index 085380c34..a5e5810ba 100644
--- a/core/src/main/java/org/apache/calcite/rex/RexSimplify.java
+++ b/core/src/main/java/org/apache/calcite/rex/RexSimplify.java
@@ -586,11 +586,7 @@ private RexNode simplifyCase(RexCall call) {
}
assert newOperands.size() % 2 == 1;
if (newOperands.size() == 1 || values.size() == 1) {
- final RexNode last = Util.last(newOperands);
- if (!call.getType().equals(last.getType())) {
- return rexBuilder.makeAbstractCast(call.getType(), last);
- }
- return last;
+ return Util.last(newOperands);
}
trueFalse:
if (call.getType().getSqlTypeName() == SqlTypeName.BOOLEAN) {
{noformat}
> simplifyCoalesce of constant should match nullability
> -----------------------------------------------------
>
> Key: CALCITE-2455
> URL: https://issues.apache.org/jira/browse/CALCITE-2455
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.17.0
> Reporter: Yuzhao Chen
> Assignee: Julian Hyde
> Priority: Major
> Fix For: 1.18.0
>
>
> After CALCITE-2227, we will not replace Coalesce to Case When for natural
> join, when we use ReduceExpressionRule for our plan for Coalesce with
> constant, the nullability will chage( from nullable to notnull), this will
> cause VolcanoPlanner to throw error.
> Should i fix this? or we should not use this rule in VolcanoPlanner?
> This is the error thrown sql :
> {code:java}
> select * from lateral (select * from scott_emp) as e
> join (table scott_dept) using (deptno)
> where e.deptno = 10 {code}
> The plan before ReduceExpressionRule:
> {code:java}
> LogicalProject(deptno=[COALESCE($7, $8)], empno=[$0], ename=[$1], job=[$2],
> mgr= [$3], hiredate=[$4], sal=[$5], comm=[$6], dname=[$9], loc=[$10])
> +- LogicalFilter(condition=[=($7, 10)])
> +- LogicalJoin(condition=[=($7, $8)], joinType=[inner])
> :- LogicalProject(empno=[$0], ename=[$1], job=[$2], mgr=[$3], hiredate=[$4],
> sal=[$5], comm=[$6], deptno=[$7])
> : +- LogicalTableScan(table=[[scott_emp]])
> +- LogicalProject(deptno=[$0], dname=[$1], loc=[$2])
> +- LogicalTableScan(table=[[scott_dept]])
> {code}
> The plan after:
> {code:java}
> LogicalProject(deptno=[10], empno=[$0], ename=[$1], job=[$2], mgr=[$3],
> hiredate=[$4], sal=[$5], comm=[$6], dname=[$9], loc=[$10])
> +- LogicalFilter(condition=[=($7, 10)])
> +- LogicalJoin(condition=[=($7, $8)], joinType=[inner])
> :- LogicalProject(empno=[$0], ename=[$1], job=[$2], mgr=[$3], hiredate=[$4],
> sal=[$5], comm=[$6], deptno=[$7])
> : +- LogicalTableScan(table=[[scott_emp]])
> +- LogicalProject(deptno=[$0], dname=[$1], loc=[$2])
> +- LogicalTableScan(table=[[scott_dept]])
> {code}
> We can see that the deptno's nullability changes from nullable to not null.
> And we encounter an type error when using ReduceExpressionRule in
> VolcanoPlanner.
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