apache/iceberg · error · UnsupportedOperationException

Cannot call refresh on temporary table operations

Error message

Cannot call refresh on temporary table operations

What it means

HiveTableOperations contains an inner temporary TableOperations used for committing metadata produced outside normal refresh/commit flow (e.g. Hive metadata updates in HiveCatalog). Refresh is intentionally unsupported there and throws UnsupportedOperationException. This is an internal-invariant error: a caller invoked an operation that has no meaning for this ephemeral object.

Source

Thrown at hive-metastore/src/main/java/org/apache/iceberg/hive/HiveTableOperations.java:468

    return TableType.EXTERNAL_TABLE;
  }

  @Override
  public ClientPool<IMetaStoreClient, TException> metaClients() {
    return metaClients;
  }

  @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 HiveTableOperations.this.metadataFileLocation(uncommittedMetadata, fileName);
      }

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

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Load a fresh Table from the catalog instead of refreshing the temporary operations-backed table
2. Use the real HiveTableOperations-backed Table (catalog.loadTable) for refresh semantics
3. Do not call refresh/commit on internal temporary operations objects; only use their metadataFileLocation/metadata helpers

Example fix

// before
tempOperations.refresh(); // UnsupportedOperationException
// after
Table fresh = catalog.loadTable(tableIdent);
fresh.refresh();

if (ops instanceof HiveTableOperations) { /* refresh is safe */ } else { load fresh table from catalog }

boolean supportsRefresh(TableOperations ops) {
  return ops instanceof HiveTableOperations;
}

try {
  table.refresh();
} catch (UnsupportedOperationException e) {
  table = catalog.loadTable(ident); // reload instead
}

When it happens

Trigger: Calling refresh() (directly or via Table.refresh()) on the temporary table operations instance returned/used by Hive metadata-handling paths; tests exercise it via the temporary operations object.

Common situations: Application code that obtained a Table backed by temporary operations and calls refresh(); framework code reusing HiveCatalog internals incorrectly; tests verifying the unsupported behavior.

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 commit on temporary table operations
• %s doesn't implement copyWithStats
• %s doesn't implement validateFilesExist
• Can't retrieve values from an empty struct
• Can't modify an empty struct

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/6136ef437132ad59. Report an issue: GitHub.