If you attempt to reference a column in one of the lambda arguments to reduce_agg and that column isn't the input to reduce_agg (i.e. the first argument), Trino will throw a null pointer exception.
> create table lambda_cap_test (col1 int, col2 int);
> select reduce_agg(col1, 0, (a, b) -> col2, (a, b) -> 0) from lambda_cap_test;
Query 20230118_205314_00004_dsgu5 failed: Internal error
java.lang.NullPointerException
at java.base/java.util.Objects.requireNonNull(Objects.java:208)
at java.base/java.util.Optional.of(Optional.java:113)
at io.trino.sql.planner.TranslationMap.getSymbolForColumn(TranslationMap.java:1116)
at io.trino.sql.planner.TranslationMap$1.rewriteIdentifier(TranslationMap.java:267)
at io.trino.sql.planner.TranslationMap$1.rewriteIdentifier(TranslationMap.java:227)
at io.trino.sql.tree.ExpressionTreeRewriter$RewritingVisitor.visitIdentifier(ExpressionTreeRewriter.java:809)
at io.trino.sql.tree.ExpressionTreeRewriter$RewritingVisitor.visitIdentifier(ExpressionTreeRewriter.java:70)
at io.trino.sql.tree.Identifier.accept(Identifier.java:91)
at io.trino.sql.tree.AstVisitor.process(AstVisitor.java:27)
...
There should be a more informative error message.
Note that if you group over this column, you will get an IllegalArgumentException instead, which is more helpful.
select reduce_agg(col1, 0, (a, b) -> a + col2, (a, b) -> 0) from lambda_cap_test group by col2;
Query 20230118_204201_00000_dsgu5 failed: argument must be symbol or lambda expression: BindExpression
conor-mcavoy
commented
1 year ago
If you attempt to reference a column in one of the lambda arguments to
reduce_aggand that column isn't the input toreduce_agg(i.e. the first argument), Trino will throw a null pointer exception.There should be a more informative error message.
Note that if you group over this column, you will get an
IllegalArgumentExceptioninstead, which is more helpful.