apache/iceberg · error · UnsupportedOperationException

Unknown field ordinal:

Error message

Unknown field ordinal: 

What it means

ManifestFileWrapper.get(pos) maps fixed ordinals 0-11 to V1 manifest-list schema columns. An ordinal outside that range has no corresponding field, so the wrapper throws UnsupportedOperationException with the offending pos. This indicates the caller is using a struct position that does not exist in the V1 manifest list schema.

Source

Thrown at core/src/main/java/org/apache/iceberg/V1Metadata.java:103

          return snapshotId();
        case 4:
          return addedFilesCount();
        case 5:
          return existingFilesCount();
        case 6:
          return deletedFilesCount();
        case 7:
          return partitions();
        case 8:
          return addedRowsCount();
        case 9:
          return existingRowsCount();
        case 10:
          return deletedRowsCount();
        case 11:
          return keyMetadata();
        default:
          throw new UnsupportedOperationException("Unknown field ordinal: " + pos);
      }
    }

    @Override
    public String path() {
      return wrapped.path();
    }

    @Override
    public long length() {
      return wrapped.length();
    }

    @Override
    public int partitionSpecId() {
      return wrapped.partitionSpecId();
    }

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Use pos values only within 0-11 for V1 manifest files; derive the bound from size() rather than hardcoding
2. Check you are not reading a V2-schema field from a V1 wrapper; use V2Metadata wrappers for V2 tables
3. Inspect the pos value in the message and map it against MANIFEST_LIST_SCHEMA.columns()

Example fix

// before
Object v = wrapper.get(13); // V2-only ordinal
// after
Object v = wrapper.get(pos < wrapper.size() ? pos : -1); // guard by size()

if (pos < 0 || pos >= MANIFEST_LIST_SCHEMA.columns().size()) { throw new IllegalArgumentException("ordinal out of range for manifest list schema"); }

boolean validManifestPos(int pos) { return pos >= 0 && pos < MANIFEST_LIST_SCHEMA.columns().size(); }

try { return wrapper.get(pos); } catch (UnsupportedOperationException e) { LOG.warn("bad ordinal {} for V1 manifest wrapper", pos); return null; }

When it happens

Trigger: Calling get(pos) with pos < 0 or pos > 11 on a V1Metadata.ManifestFileWrapper, typically from generic StructLike iteration code that assumes a different schema version or struct shape.

Common situations: Code written against the V2 manifest schema (extra columns like partitions/sequence numbers) applied to a V1 table's manifest wrappers; off-by-one loops over struct fields using a wrong size constant.

Related errors

• Unknown field ordinal:
• Field + name + not found in source schema
• Cannot parse type string to primitive: + typeString
• Invalid default value for %s: %s (must be null)
• Unknown field ordinal: ${basePos}

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/d181cb7b34bb1d45. Report an issue: GitHub.