apache/iceberg · error · UnsupportedOperationException

Cannot call commit on temporary table operations

Error message

Cannot call commit on temporary table operations

What it means

The temporary TableOperations created during commit cannot commit itself; its commit() unconditionally throws UnsupportedOperationException. Commits must be issued on the outer HadoopTableOperations instance. This prevents recursive/invalid commit state transitions.

Source

Thrown at core/src/main/java/org/apache/iceberg/hadoop/HadoopTableOperations.java:205

  }

  @Override
  public TableOperations temp(TableMetadata uncommittedMetadata) {
    return new TableOperations() {
      @Override
      public TableMetadata current() {
        return uncommittedMetadata;
      }

      @Override
      public TableMetadata refresh() {
        throw new UnsupportedOperationException(
            "Cannot call refresh on temporary table operations");
      }

      @Override
      public void commit(TableMetadata base, TableMetadata metadata) {
        throw new UnsupportedOperationException("Cannot call commit on temporary table operations");
      }

      @Override
      public String metadataFileLocation(String fileName) {
        return HadoopTableOperations.this.metadataFileLocation(fileName);
      }

      @Override
      public LocationProvider locationProvider() {
        return LocationProviders.locationsFor(
            uncommittedMetadata.location(), uncommittedMetadata.properties());
      }

      @Override
      public FileIO io() {
        return HadoopTableOperations.this.io();
      }

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Call commit() only on the outer HadoopTableOperations, never on the temporary instance
2. Move any additional writes after the outer commit completes
3. Refactor commit hooks to only read state (current()) rather than mutate

Example fix

// before
tempOps.commit(base, metadata); // inside commit flow
// after
hadoopOps.commit(base, metadata); // commit on the real operations

if (isTemporaryOps(ops)) { /* do not commit */ }

boolean isCommittable(TableOperations ops) { return ops instanceof HadoopTableOperations; }

When it happens

Trigger: Calling commit() on the temporary operations instance yielded during a commit transaction; nested commit attempts inside commit hooks or listeners.

Common situations: Framework code that wraps any TableOperations and calls commit on it during another commit; accidental variable shadowing where tempOps is used instead of the real ops reference.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Cannot call refresh on temporary table operations
• Cannot call commit on temporary table operations
• Update type %s is not supported
• Cannot call commit on temporary table operations
• Cannot call commit on temporary table operations

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/7ab60e51548018f1. Report an issue: GitHub.