What causes "StringAnyAggregator does not support getLong()" in apache/druid?

Read the value via getString() and cast to long in a CastPostAggregator if numeric consumption is required

apache/druid · error · UnsupportedOperationException

StringAnyAggregator does not support getLong()

Error message

StringAnyAggregator does not support getLong()

What it means

StringAnyAggregator's getLong() throws UnsupportedOperationException with this message because the aggregator's value is a string and cannot be exposed as a long. The class implements typed accessors only to reject them clearly rather than silently coercing or returning a sentinel value.

Solutions

Read the value via getString() and cast to long in a CastPostAggregator if numeric consumption is required
Aggregate the numeric column itself (longAny/longSum) rather than its string representation
Change downstream post-aggregators to accept string results (string post-aggregators)
Correct type mappings in ingestion so the column's type matches the aggregator usage

Example fix

// before
aggregatorSelector.getLong() on stringAny result
// after
String v = aggregatorSelector.getString();
long l = v == null ? 0L : Long.parseLong(v); // or a CastPostAggregator to LONG

Defensive patterns

Strategy: type-guard

Validate before calling

if (aggregator instanceof StringAnyAggregator) {
  throw new ISE("stringAny metric cannot be read as long");
}

Type guard

boolean supportsLong(Aggregator a) { return !(a instanceof StringAnyAggregator); }

Try / catch

try {
  long l = aggregator.getLong();
} catch (UnsupportedOperationException e) {
  String s = aggregator.getString();
  long l = s == null ? 0L : Long.parseLong(s);
}

Prevention

Only call getLong() on long-typed aggregators; use getString() for stringAny
Insert cast post-aggregators when a string value must become numeric
Verify column types at ingestion so numeric columns are not stored as strings
Generic result consumers should branch on aggregator type before accessor calls

When it happens

Trigger: A post-aggregator or result-row accessor calls getLong() on the output of a stringAny aggregator; e.g. a longSum post-aggregator or numeric expression expecting a long-typed field wired to a string-valued any aggregation.

Common situations: Hand-written native queries mixing string and numeric aggregators under one post-aggregator; SQL queries where a numeric column was ingested as string and aggregated with any then consumed numerically.

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/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/f8588bb1e0ccac04. Report an issue: GitHub.

Appendix: source

Thrown at processing/src/main/java/org/apache/druid/query/aggregation/any/StringAnyAggregator.java:92

    return DimensionHandlerUtils.convertObjectToString(object);
  }

  @Override
  public Object get()
  {
    return foundValue;
  }

  @Override
  public float getFloat()
  {
    throw new UnsupportedOperationException("StringAnyAggregator does not support getFloat()");
  }

  @Override
  public long getLong()
  {
    throw new UnsupportedOperationException("StringAnyAggregator does not support getLong()");
  }

  @Override
  public double getDouble()
  {
    throw new UnsupportedOperationException("StringAnyAggregator does not support getDouble()");
  }

  @Override
  public void close()
  {
    // no-op
  }
}

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