apache/iceberg · error · IllegalArgumentException

Unexpected delete file content:

Error message

Unexpected delete file content: 

What it means

When aggregating TableChanges, each delete file's content() must be one of the known delete content kinds (position deletes or equality deletes). If a ContentFile reports some other delete content type, the constructor throws IllegalArgumentException, because the maintenance metrics cannot be classified.

Source

Thrown at flink/v2.3/flink/src/main/java/org/apache/iceberg/flink/maintenance/operator/TableChange.java:85

    dataFiles.forEach(
        dataFile -> {
          this.dataFileCount++;
          this.dataFileSizeInBytes += dataFile.fileSizeInBytes();
        });

    deleteFiles.forEach(
        deleteFile -> {
          switch (deleteFile.content()) {
            case POSITION_DELETES:
              this.posDeleteFileCount++;
              this.posDeleteRecordCount += deleteFile.recordCount();
              break;
            case EQUALITY_DELETES:
              this.eqDeleteFileCount++;
              this.eqDeleteRecordCount += deleteFile.recordCount();
              break;
            default:
              throw new IllegalArgumentException("Unexpected delete file content: " + deleteFile);
          }
        });

    this.commitCount = 1;
  }

  static TableChange empty() {
    return new TableChange(0, 0L, 0, 0L, 0, 0L, 0);
  }

  public static Builder builder() {
    return new Builder();
  }

  int dataFileCount() {
    return dataFileCount;
  }

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Upgrade the iceberg-flink-runtime dependency to a version that recognizes the delete content type used by the writers
2. Check which jobs/writers produce the delete files and align Iceberg versions across the pipeline
3. Inspect the offending ContentFile.content() value and confirm the table was not written by an experimental/newer format
4. If a custom ContentFile is in play, fix it to return only the supported delete content types

Example fix

// before: older runtime reading DV-based delete files
TableChange change = new TableChange(tableLoader, ...); // IllegalArgumentException: Unexpected delete file content: ...
// after: upgrade runtime
implementation('org.apache.iceberg:iceberg-flink-runtime-1.20:<newer-version>');

// before building TableChange from delete files
Set<ContentFile.Content> supported = EnumSet.of(ContentFile.Content.POSITION_DELETES, ContentFile.Content.EQUALITY_DELETES);
for (ContentFile<?> f : deleteFiles) {
  Preconditions.checkState(f.content() != ContentFile.Content.DATA && supported.contains(f.content()),
      "Unsupported delete content %s", f.content());
}

static boolean isSupportedDeleteContent(ContentFile<?> f) {
  return f.content() == ContentFile.Content.POSITION_DELETES || f.content() == ContentFile.Content.EQUALITY_DELETES;
}

try {
  new TableChange(...);
} catch (IllegalArgumentException e) {
  LOG.error("Unknown delete content; runtime too old for this table's writers", e);
  throw e;
}

When it happens

Trigger: Encountering a delete file whose content() is a new/unknown Iceberg content type (e.g. written by a newer Iceberg writer using content kinds unknown to this version) while building a TableChange from a table's new files.

Common situations: Tables written by a newer Iceberg engine version with delete kinds this Flink runtime doesn't know; custom file implementations returning unexpected content(); reading a table written with DVs/other content by a mismatched runtime.

Related errors

• Unsupported delete file type:
• Unexpected delete file content: <deleteFile>
• Fail to deserialize aggregated statistics,change to v1
• Failed to deserialize IcebergSourceSplit. Encountered unsupp
• Unrecognized version or corrupt state:

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/56ee5e977ac49b1b. Report an issue: GitHub.