apache/cassandra · error · InvalidRequestException

Index ' ' already exists

Error message

Index '%s' already exists

What it means

CreateIndexStatement.apply: an index with the given/generated name already exists in the keyspace and IF NOT EXISTS was not specified, so creation is rejected to avoid silently overwriting index definitions.

Solutions

1. Use IF NOT EXISTS if the existing index is acceptable.
2. Drop the existing index (DROP INDEX) or choose a different index name.

When it happens

Trigger: Thrown at src/java/org/apache/cassandra/cql3/statements/schema/CreateIndexStatement.java:168 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/ee225ccb54f7508d. Report an issue: GitHub.

Appendix: source

Thrown at src/java/org/apache/cassandra/cql3/statements/schema/CreateIndexStatement.java:168

        if (attrs.isCustom && attrs.customClass.equals(SASIIndex.class.getName()) && !DatabaseDescriptor.getSASIIndexesEnabled())
            throw new InvalidRequestException(SASI_INDEX_DISABLED);

        Keyspaces schema = metadata.schema.getKeyspaces();
        KeyspaceMetadata keyspace = schema.getNullable(keyspaceName);
        if (null == keyspace)
            throw ire(KEYSPACE_DOES_NOT_EXIST, keyspaceName);

        TableMetadata table = keyspace.getTableOrViewNullable(tableName);
        if (null == table)
            throw ire(TABLE_DOES_NOT_EXIST, tableName);

        if (null != indexName && keyspace.hasIndex(indexName))
        {
            if (ifNotExists)
                return schema;

            throw ire(INDEX_ALREADY_EXISTS, indexName);
        }

        if (table.isCounter())
            throw ire(COUNTER_TABLES_NOT_SUPPORTED);

        if (table.isView())
            throw ire(MATERIALIZED_VIEWS_NOT_SUPPORTED);

        if (keyspace.replicationStrategy.hasTransientReplicas())
            throw new InvalidRequestException(TRANSIENTLY_REPLICATED_KEYSPACE_NOT_SUPPORTED);

        // guardrails to limit number of secondary indexes per table.
        Guardrails.secondaryIndexesPerTable.guard(table.indexes.size() + 1,
                                                  Strings.isNullOrEmpty(indexName)
                                                  ? String.format("on table %s", table.name)
                                                  : String.format("%s on table %s", indexName, table.name),
                                                  false,
                                                  state);

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