apache/iceberg · error · UnsupportedOperationException

does not have a format version

Error message

 does not have a format version

What it means

SerializableTable records the table's format version at serialization time. If the version was unknown (UNKNOWN_FORMAT_VERSION, e.g., the source TableOperations did not expose it), formatVersion() throws UnsupportedOperationException naming the concrete class.

Solutions

  1. Read the format version from the underlying TableMetadata before serializing
  2. Ensure the table is loaded from a catalog so its metadata includes the format version
  3. Guard with a check against SerializableTable.UNKNOWN_FORMAT_VERSION-equivalent state before calling
Defensive patterns

Strategy: type-guard

Validate before calling

if (table instanceof SerializableTable) { /* format version may be unknown */ } else { int v = table.operations().current().formatVersion(); }

Type guard

boolean hasFormatVersion = !(table instanceof SerializableTable);

Try / catch

try { v = st.formatVersion(); } catch (UnsupportedOperationException e) { v = MetadataTableUtils...; }

Prevention

When it happens

Trigger: Calling formatVersion() on a SerializableTable that was built from a table whose format version could not be captured (unknown format version sentinel).

Common situations: Reading format version from a table deserialized without version info; custom/in-memory TableOperations implementations not reporting the version.

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

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/ef707460be5befca. Report an issue: GitHub.

Appendix: source

Thrown at core/src/main/java/org/apache/iceberg/SerializableTable.java:173

  @Override
  public String name() {
    return name;
  }

  @Override
  public String location() {
    return location;
  }

  @Override
  public Map<String, String> properties() {
    return properties;
  }

  public int formatVersion() {
    if (formatVersion == UNKNOWN_FORMAT_VERSION) {
      throw new UnsupportedOperationException(
          this.getClass().getName() + " does not have a format version");
    }
    return formatVersion;
  }

  private int formatVersion(Table table) {
    try {
      return TableUtil.formatVersion(table);
    } catch (IllegalArgumentException e) {
      return UNKNOWN_FORMAT_VERSION;
    }
  }

  @Override
  public Schema schema() {
    if (lazySchema == null) {
      synchronized (this) {
        if (lazySchema == null && lazyTable == null) {

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