apache/druid · error · IllegalArgumentException

No such join algorithm

Error message

No such join algorithm [%s]. Supported values are: %s

What it means

JoinAlgorithm is a closed enum (broadcast, sort-merge) parsed from its string id via fromString/JsonCreator. An unrecognized id throws this IllegalArgumentException listing the supported values, since joins cannot proceed without a valid algorithm choice.

Solutions

1. Use one of the supported values listed in the error message (e.g. "broadcast" or "sortMerge").
2. Check the exact spelling/casing against the enum ids in your Druid version.
3. If migrating from another version, consult that version's JoinAlgorithm enum for valid ids.

Example fix

// before
"joinAlgorithm": "hash"
// after
"joinAlgorithm": "broadcast"

Set<String> valid = Set.of("broadcast", "sortMerge");
if (joinAlgorithm != null && !valid.contains(joinAlgorithm)) {
  throw new IllegalArgumentException("Unsupported joinAlgorithm: " + joinAlgorithm);
}

try {
  JoinAlgorithm alg = JoinAlgorithm.fromString(id);
} catch (IllegalArgumentException e) {
  alg = JoinAlgorithm.BROADCAST; // or surface a friendly message
}

When it happens

Trigger: Submitting a query or datasource JSON with "joinAlgorithm":"something" that isn't one of the enum's ids, or an older client string no longer supported by this Druid version.

Common situations: Typos in joinAlgorithm in hand-written native query JSON; clients written against a different Druid version with different supported algorithms; case-sensitivity mistakes in the id.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• Ambiguous directions
• BroadcastTablesTooLarge
• Caching is not supported. Check `isCacheable` before…
• Cannot build hash-join matcher on non-equi-join condition
• Cannot build hash-join matcher on non-key-based condition

AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/653ac2f0ecce7ad4. Report an issue: GitHub.

Appendix: source

Thrown at processing/src/main/java/org/apache/druid/query/JoinAlgorithm.java:61

  };

  private final String id;

  JoinAlgorithm(String id)
  {
    this.id = id;
  }

  @JsonCreator
  public static JoinAlgorithm fromString(final String id)
  {
    for (final JoinAlgorithm value : values()) {
      if (value.id.equals(id)) {
        return value;
      }
    }

    throw new IAE("No such join algorithm [%s]. Supported values are: %s", id, Arrays.toString(values()));
  }

  @JsonValue
  public String getId()
  {
    return id;
  }

  /**
   * Whether this join algorithm requires subqueries for all inputs.
   */
  public abstract boolean requiresSubquery();

  @Override
  public String toString()
  {
    return id;
  }

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