prestodb/presto · error · IllegalArgumentException

expecting SpecialFormExpression(DEREFERENCE) with constants

Error message

expecting SpecialFormExpression(DEREFERENCE) with constants for indices, but got: 

What it means

Internal shape check while flattening DEREFERENCE chains in createNestedColumn: an array/struct index within the dereference chain did not optimize to a ConstantExpression holding a Number. The rule only pushes down constant indices; anything else violates the invariant — planner bug or unexpected expression form.

Source

Thrown at presto-parquet/src/main/java/com/facebook/presto/parquet/rule/ParquetDereferencePushDown.java:202

                        ExpressionOptimizer.Level.OPTIMIZED,
                        session);

                if (indexExpression instanceof ConstantExpression) {
                    Object index = ((ConstantExpression) indexExpression).getValue();
                    if (index instanceof Number) {
                        Optional<String> fieldName = baseType.getFields().get(((Number) index).intValue()).getName();
                        if (fieldName.isPresent()) {
                            elements.add(new Subfield.NestedField(fieldName.get()));
                            currentRowExpression = base;
                            continue;
                        }
                    }
                }
            }
            break;
        }

        throw new IllegalArgumentException("expecting SpecialFormExpression(DEREFERENCE) with constants for indices, but got: " + currentRowExpression);
    }

    /**
     * Visitor to extract all dereference expressions and variable references.
     * <p>
     * If a dereference expression contains dereference expression, inner dereference expression are not returned
     * * sub(deref(deref(x, 1), 2)) --> deref(deref(x,1), 2)
     * Variable expressions returned are the ones not referenced by the dereference expressions
     * * sub(x + 1) --> x
     * * sub(deref(x, 1)) -> deref(x,1)
     */
    private static class ExtractDereferenceAndVariables
            extends DefaultRowExpressionTraversalVisitor<Set<RowExpression>>
    {
        private final ConnectorSession connectorSession;
        private final ExpressionOptimizer expressionOptimizer;

        public ExtractDereferenceAndVariables(ConnectorSession connectorSession, ExpressionOptimizer expressionOptimizer)

View on GitHub (pinned to 55bb57d202)

Solutions

1. Report the query/plan as a Presto planner bug
2. Disable the parquet dereference pushdown rule as a workaround
3. Ensure indices in nested accesses are literal constants in the query

When it happens

Trigger: Thrown at presto-parquet/src/main/java/com/facebook/presto/parquet/rule/ParquetDereferencePushDown.java:202 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/e64227255b759ca2. Report an issue: GitHub.