apache/iceberg · error · IllegalStateException

Not a set predicate:

Error message

Not a set predicate: 

What it means

BoundSetPredicate represents IN/NOT_IN predicates over a set of literals; asSetPredicate() is the narrowing accessor for it. The base BoundPredicate throws IllegalStateException here because most bound predicates (comparisons, unary predicates) are not set predicates. Guard with isSetPredicate() before calling.

Solutions

1. Check predicate.isSetPredicate() before calling asSetPredicate()
2. Branch on predicate kind before accessing set-specific state
3. Ensure the expression was bound with Binder.bind; binding normalizes single-element IN into literal predicates

Example fix

// before
BoundSetPredicate<?> set = boundPred.asSetPredicate();
// after
if (boundPred.isSetPredicate()) {
  BoundSetPredicate<?> set = boundPred.asSetPredicate();
}

if (!pred.isSetPredicate()) { throw new IllegalArgumentException("expected set predicate, got " + pred.op()); }

function asSet(p) { return p.isSetPredicate() ? p.asSetPredicate() : null; }

try { set = pred.asSetPredicate(); } catch (IllegalStateException e) { /* handle non-set predicate */ }

When it happens

Trigger: Calling asSetPredicate() on a BoundPredicate that is actually a BoundLiteralPredicate or BoundUnaryPredicate, e.g. when collecting IN clause literals from a bound expression without checking the predicate kind.

Common situations: Scan-planning or partition-pruning code that extracts IN-set values from filter expressions but encounters a simple == or IS NULL predicate instead.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

• Not a literal predicate:
• 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/e4e1a6c957c650c7. Report an issue: GitHub.

Appendix: source

Thrown at api/src/main/java/org/apache/iceberg/expressions/BoundPredicate.java:66

  public BoundUnaryPredicate<T> asUnaryPredicate() {
    throw new IllegalStateException("Not a unary predicate: " + this);
  }

  public boolean isLiteralPredicate() {
    return false;
  }

  public BoundLiteralPredicate<T> asLiteralPredicate() {
    throw new IllegalStateException("Not a literal predicate: " + this);
  }

  public boolean isSetPredicate() {
    return false;
  }

  public BoundSetPredicate<T> asSetPredicate() {
    throw new IllegalStateException("Not a set predicate: " + this);
  }
}

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