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[fix](planner)isnull predicate can't be safely constant folded in inlineview (#25377)

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disable is null predicate constant fold rule for inline view
consider sql
select c.*
from (
select a.*, b.x
from test_insert a left join
(select 'some_const_str' x from test_insert) b on true
) c
where c.x is null;

when push “c.x is null” into c, after folding constant rule, it will get empty result. Because x is 'some_const_str' and "x is null" will be evaluated to false. This is wrong.
This commit is contained in:
starocean999
2023-11-08 20:46:29 +08:00
committed by GitHub
parent d749d99fe2
commit 0c1458f21f
3 changed files with 12 additions and 2 deletions
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2
fe/fe-core/src/main/java/org/apache/doris/analysis/IsNullPredicate.java
View File

@ -160,7 +160,7 @@ public class IsNullPredicate extends Predicate {
// after outer join
recursiveResetChildrenResult(!forPushDownPredicatesToView);
final Expr childValue = getChild(0);
if (!(childValue instanceof LiteralExpr)) {
if (forPushDownPredicatesToView || !(childValue instanceof LiteralExpr)) {
return this;
}
return childValue instanceof NullLiteral ? new BoolLiteral(!isNotNull) : new BoolLiteral(isNotNull);

6
fe/fe-core/src/main/java/org/apache/doris/rewrite/FoldConstantsRule.java
View File

@ -29,6 +29,7 @@ import org.apache.doris.analysis.Expr;
import org.apache.doris.analysis.InformationFunction;
import org.apache.doris.analysis.LiteralExpr;
import org.apache.doris.analysis.NullLiteral;
import org.apache.doris.analysis.SlotRef;
import org.apache.doris.analysis.VariableExpr;
import org.apache.doris.catalog.Env;
import org.apache.doris.catalog.PrimitiveType;
@ -124,7 +125,10 @@ public class FoldConstantsRule implements ExprRewriteRule {
return expr;
}
}
return expr.getResultValue(false);
// it may be wrong to fold constant value in inline view
// so pass the info to getResultValue method to let predicate itself
// to decide if it can fold constant value safely
return expr.getResultValue(expr instanceof SlotRef ? false : analyzer.isInlineViewAnalyzer());
}
/**