apache/cassandra · error · InvalidRequestException

A user type with name

Error message

A user type with name '%s' already exists

What it means

Duplicate guard in CREATE TYPE: a user type with the same name already exists in the keyspace. Unless IF NOT EXISTS was given, the statement is rejected to prevent silently overwriting the existing type definition.

Solutions

1. Use IF NOT EXISTS to tolerate the existing type.
2. DROP TYPE the old definition or choose a different type name.

When it happens

Trigger: Thrown at src/java/org/apache/cassandra/cql3/statements/schema/CreateTypeStatement.java:101 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/18b24dbe275e1ed1. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/cql3/statements/schema/CreateTypeStatement.java:101

    public boolean compatibleWith(ClusterMetadata metadata)
    {
        return metadata.directory.commonSerializationVersion.isAtLeast(Version.V0);
    }

    public Keyspaces apply(ClusterMetadata metadata)
    {
        Keyspaces schema = metadata.schema.getKeyspaces();
        KeyspaceMetadata keyspace = schema.getNullable(keyspaceName);
        if (null == keyspace)
            throw ire("Keyspace '%s' doesn't exist", keyspaceName);

        UserType existingType = keyspace.types.getNullable(bytes(typeName));
        if (null != existingType)
        {
            if (ifNotExists)
                return schema;

            throw ire("A user type with name '%s' already exists", typeName);
        }

        Set<FieldIdentifier> usedNames = new HashSet<>();
        for (FieldIdentifier name : fieldNames)
            if (!usedNames.add(name))
                throw ire("Duplicate field name '%s' in type '%s'", name, typeName);

        for (CQL3Type.Raw type : rawFieldTypes)
        {
            if (type.isCounter())
                throw ire("A user type cannot contain counters");

            if (type.isUDT() && !type.isFrozen())
                throw ire("A user type cannot contain non-frozen UDTs");
        }

        List<AbstractType<?>> fieldTypes =
            rawFieldTypes.stream()

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