apache/iceberg · error · IllegalStateException

Invalid operation for BoundUnaryPredicate:

Error message

Invalid operation for BoundUnaryPredicate: 

What it means

BoundUnaryPredicate.test() supports only IS_NULL, NOT_NULL, IS_NAN and NOT_NAN operations. Any other operation reaches the default branch and throws IllegalStateException. A BoundUnaryPredicate should never hold other operations, so this signals corrupted construction or an unsafe rewrite.

Solutions

1. Only assign unary operations (IS_NULL, NOT_NULL, IS_NAN, NOT_NAN) to BoundUnaryPredicate
2. Check op() before calling test() in generic evaluation code
3. Report a bug if this fires with unmodified Iceberg APIs

Example fix

// before
unaryPred.test(row.get(pos, type));
// after
switch (unaryPred.op()) {
  case IS_NULL: case NOT_NULL: case IS_NAN: case NOT_NAN:
    unaryPred.test(row.get(pos, type));
    break;
}

Set<Operation> OK = Set.of(Operation.IS_NULL, Operation.NOT_NULL, Operation.IS_NAN, Operation.NOT_NAN); if (!OK.contains(pred.op())) { throw new IllegalArgumentException("BoundUnaryPredicate requires a unary op"); }

boolean evaluableUnary = pred.op() == Operation.IS_NULL || pred.op() == Operation.NOT_NULL || pred.op() == Operation.IS_NAN || pred.op() == Operation.NOT_NAN;

try { result = unaryPred.test(value); } catch (IllegalStateException e) { /* corrupt operation: log and fail fast */ }

When it happens

Trigger: Evaluating a BoundUnaryPredicate whose op() is something other than the four supported unary operations — only possible through misuse of internal constructors or custom rewrites.

Common situations: Custom expression transformation code that mutates operations without matching the predicate class to the operation kind.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• Invalid operation for BoundSetPredicate:
• AboveMax has no comparator
• BelowMin has no comparator
• BelowMin has no value
• Cannot change the type of BelowMin

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/fd031bf4d955bc13. Report an issue: GitHub.

Appendix: source

Thrown at api/src/main/java/org/apache/iceberg/expressions/BoundUnaryPredicate.java:55

  @Override
  public BoundUnaryPredicate<T> asUnaryPredicate() {
    return this;
  }

  @Override
  public boolean test(T value) {
    switch (op()) {
      case IS_NULL:
        return value == null;
      case NOT_NULL:
        return value != null;
      case IS_NAN:
        return NaNUtil.isNaN(value);
      case NOT_NAN:
        return !NaNUtil.isNaN(value);
      default:
        throw new IllegalStateException("Invalid operation for BoundUnaryPredicate: " + op());
    }
  }

  @Override
  public boolean isEquivalentTo(Expression other) {
    if (op() == other.op()) {
      return term().isEquivalentTo(((BoundUnaryPredicate<?>) other).term());
    }

    return false;
  }

  @Override
  public String toString() {
    switch (op()) {
      case IS_NULL:
        return "is_null(" + term() + ")";
      case NOT_NULL:

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