apache/iceberg · error · UnsupportedOperationException

UnsupportedOperationException

Error message

UnsupportedOperationException

What it means

UpdateSchema.caseSensitive(boolean) is a default method that throws an UnsupportedOperationException with no message when the implementation does not support configuring case sensitivity for column-name resolution during schema updates. It is used by EvolveSchemaVisitor and callers that need to control name matching.

Source

Thrown at api/src/main/java/org/apache/iceberg/UpdateSchema.java:660

  /**
   * Set the identifier fields given some field names. See {@link
   * UpdateSchema#setIdentifierFields(Collection)} for more details.
   *
   * @param names names of the columns to set as identifier fields
   * @return this for method chaining
   */
  default UpdateSchema setIdentifierFields(String... names) {
    return setIdentifierFields(Sets.newHashSet(names));
  }

  /**
   * Determines if the case of schema needs to be considered when comparing column names
   *
   * @param caseSensitive when false case is not considered in column name comparisons.
   * @return this for method chaining
   */
  default UpdateSchema caseSensitive(boolean caseSensitive) {
    throw new UnsupportedOperationException();
  }
}

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Use the table's own updateSchema() implementation, which typically supports case sensitivity.
2. Match column names using the default case convention of the implementation instead of toggling case sensitivity.
3. Upgrade Iceberg if a newer version added support to your implementation class.
4. Implement caseSensitive() if you own the UpdateSchema implementation.

Example fix

// before
transaction.updateSchema().caseSensitive(false).renameColumn("Name", "name");

// after
table.updateSchema().caseSensitive(false).renameColumn("Name", "name");

// no public capability check; only call on implementations known to support case sensitivity

boolean supportsCaseSensitivity = updateSchema.getClass().getName().startsWith("org.apache.iceberg.BaseUpdateSchema");

try {
  updateSchema.caseSensitive(false).renameColumn("Name", "name");
} catch (UnsupportedOperationException e) {
  updateSchema.renameColumn("Name", "name"); // use implementation's default name resolution
}

When it happens

Trigger: Calling updateSchema.caseSensitive(true/false) on an UpdateSchema implementation that has not overridden the default method, e.g. during visitor-driven schema evolution on a path without case-sensitivity support.

Common situations: Renaming/moving columns with different casing through a transaction-scoped update; schema-evolution frameworks (EvolveSchemaVisitor) invoking the method generically on implementations lacking support.

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

• Default values are not supported
• Unknown field ordinal:
• Unknown move type:
• Cannot apply unknown unique constraint: {constraint.getType(
• Cannot drop identifier fields in non-Iceberg table: $table

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/783ca03715d23149. Report an issue: GitHub.