apache/cassandra · error · InvalidRequestException

Function ' ' doesn't exist

Error message

Function '%s' doesn't exist

What it means

DROP FUNCTION failed because no user-defined function with the given name exists in the target keyspace (or the keyspace itself is absent) and IF EXISTS was not given. apply() checks current schema before removing anything.

Solutions

1. Add IF EXISTS: DROP FUNCTION IF EXISTS ks.fn
2. Verify existence with SELECT function_name FROM system_schema.functions WHERE keyspace_name='ks';
3. Create the function first if the drop order in scripts is wrong

Example fix

// before
DROP FUNCTION sales.my_func;
// after
DROP FUNCTION IF EXISTS sales.my_func;

const rows = await session.execute("SELECT function_name FROM system_schema.functions WHERE keyspace_name=? AND function_name=?", [ks, name]); if (rows.rowLength === 0) return; // skip drop

try { session.execute(`DROP FUNCTION IF EXISTS ${ks}.${name}`); } catch (e) { if (e instanceof InvalidQueryError && /doesn't exist/.test(e.message)) { /* treat as no-op */ } else throw e; }

When it happens

Trigger: DROP FUNCTION ks.fn where ks or fn does not exist, without IF EXISTS.

Common situations: Typo in function or keyspace name; function already dropped; running DDL against a fresh environment lacking the UDF; case-sensitive quoted identifiers mismatch.

Understand the failure class

Background: "Not found" and "does not exist" errors: why "Task not found", "No such folder", and "Can't find" fire when a lookup comes back empty — this error's family across 14 libraries.

Related errors

• 'DROP FUNCTION ' matches multiple function definitions…
• Aggregate ' ' doesn't exist
• Argument ' ' cannot be frozen; remove frozen<> modifier from
• Argument ' ' cannot be frozen; remove frozen<> modifier from
• Cannot replace function

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/fb5ef9d334d3ad2d. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/cql3/statements/schema/DropFunctionStatement.java:94

        return metadata.directory.commonSerializationVersion.isAtLeast(Version.V0);
    }

    @Override
    public Keyspaces apply(ClusterMetadata metadata)
    {
        String name =
            argumentsSpeficied
          ? format("%s.%s(%s)", keyspaceName, functionName, join(", ", transform(arguments, CQL3Type.Raw::toString)))
          : format("%s.%s", keyspaceName, functionName);

        Keyspaces schema = metadata.schema.getKeyspaces();
        KeyspaceMetadata keyspace = schema.getNullable(keyspaceName);
        if (null == keyspace)
        {
            if (ifExists)
                return schema;

            throw ire("Function '%s' doesn't exist", name);
        }

        Collection<UserFunction> functions = keyspace.userFunctions.get(new FunctionName(keyspaceName, functionName));
        if (functions.size() > 1 && !argumentsSpeficied)
        {
            throw ire("'DROP FUNCTION %s' matches multiple function definitions; " +
                      "specify the argument types by issuing a statement like " +
                      "'DROP FUNCTION %s (type, type, ...)'. You can use cqlsh " +
                      "'DESCRIBE FUNCTION %s' command to find all overloads",
                      functionName, functionName, functionName);
        }

        arguments.stream()
                 .filter(raw -> !raw.isImplicitlyFrozen() && raw.isFrozen())
                 .findFirst()
                 .ifPresent(t -> { throw ire("Argument '%s' cannot be frozen; remove frozen<> modifier from '%s'", t, t); });

        List<AbstractType<?>> argumentTypes = prepareArgumentTypes(keyspace.types);

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