--- title: "Create a scalar index on a table" method: POST path: "/v1/table/{id}/create_scalar_index" tags: ["Table", "Index", "Metadata"] --- # Create a scalar index on a table `POST /v1/table/{id}/create_scalar_index` Create a scalar index on a table field for faster filtering operations. Supports scalar indexes (BTREE, BITMAP, LABEL_LIST, FTS, etc.). This is an alias for CreateTableIndex specifically for scalar indexes. Index creation is handled asynchronously. Use the `ListTableIndices` and `DescribeTableIndexStats` operations to monitor index creation progress. ## Path parameters - `id` string, required ## Query parameters - `delimiter` string ## Request body - CreateTableIndexRequest - `identity` Identity — Identity information of a request. - `api_key` string — API key for authentication. REST NAMESPACE ONLY This is passed via the `x-api-key` header. - `auth_token` string — Bearer token for authentication. REST NAMESPACE ONLY This is passed via the `Authorization` header with the Bearer scheme (e.g., `Bearer `). - `context` unknown - `id` string[] - `branch` string — Branch to target. When not specified, the main branch is used. - `column` string, required — Lance field path to create the index on. Nested fields use dot-separated segments; use backtick-quoted segments for literal dots and double backticks inside quoted segments. Use canonical full paths for display and errors; leaf names alone only identify top-level fields; invalid or unresolved paths should return InvalidInput or TableColumnNotFound. - `index_type` string, required — Type of index to create (e.g., BTREE, BITMAP, LABEL_LIST, IVF_FLAT, IVF_PQ, IVF_HNSW_SQ, FTS) - `name` string, nullable — Optional name for the index. If not provided, a name will be auto-generated. - `distance_type` string — Distance metric type for vector indexes (e.g., l2, cosine, dot) - `num_partitions` integer, nullable — Optional vector index parameter for the number of IVF partitions. Applies to all IVF index types. - `num_sub_vectors` integer, nullable — Optional vector index parameter for the number of PQ sub-vectors. Applies to IVF_PQ only. - `num_bits` integer, nullable — Optional vector index parameter for the number of bits used by the quantizer. - `sample_rate` integer, nullable — Optional vector index parameter for the per-partition sample rate used during IVF training. - `max_iterations` integer, nullable — Optional vector index parameter for the maximum number of IVF k-means training iterations. - `target_partition_size` integer, nullable — Optional vector index parameter for the target partition size. Alternative to num_partitions. - `m` integer, nullable — Optional vector index parameter for the number of edges per node in the HNSW graph. Applies to HNSW index types. - `ef_construction` integer, nullable — Optional vector index parameter for the number of candidates evaluated during HNSW graph construction. Applies to HNSW index types. - `with_position` boolean, nullable — Optional FTS parameter for position tracking - `base_tokenizer` string, nullable — Optional FTS parameter for base tokenizer - `language` string, nullable — Optional FTS parameter for language - `max_token_length` integer, nullable — Optional FTS parameter for maximum token length - `lower_case` boolean, nullable — Optional FTS parameter for lowercase conversion - `stem` boolean, nullable — Optional FTS parameter for stemming - `remove_stop_words` boolean, nullable — Optional FTS parameter for stop word removal - `ascii_folding` boolean, nullable — Optional FTS parameter for ASCII folding ## Response `200` Scalar index created successfully - CreateTableScalarIndexResponse — Response for create scalar index operation - `context` unknown - `transaction_id` string — Optional transaction identifier ## Other responses - `400` — Indicates a bad request error. It could be caused by an unexpected request body format or other forms of request validation failure, such as invalid json. Usually serves application/json content, although in some cases simple text/plain content might be returned by the server's middleware. - `401` — Unauthorized. The request lacks valid authentication credentials for the operation. - `403` — Forbidden. Authenticated user does not have the necessary permissions. - `404` — A server-side problem that means can not find the specified resource. - `503` — The service is not ready to handle the request. The client should wait and retry. The service may additionally send a Retry-After header to indicate when to retry. - `5XX` — A server-side problem that might not be addressable from the client side. Used for server 5xx errors without more specific documentation in individual routes. ## Changes - **2026-08-18** `541331733d0c` — 8 info - added the new optional request property `ef_construction` - added the new optional request property `m` - added the new optional request property `max_iterations` - added the new optional request property `num_bits` - …4 more - **2026-07-01** `591cd95574b0` — 7 info - added the optional property `context` to the response with the `200` status - added the optional property `context` to the response with the `400` status - added the optional property `context` to the response with the `401` status - added the optional property `context` to the response with the `403` status - …3 more - **2026-06-10** `a3308034a3cd` — 1 breaking - the `column` request property's minLength was increased from `0` to `1` - **2026-06-05** `9932582b6bd7` — 1 info - added the new optional request property `branch` - **2026-01-02** `83f8516f0507` — 1 info - added the new optional request property `context` [Full history](https://skmtc.dev/lance-format/apis/lance-namespace-specification/changes/v1/table/:id/create_scalar_index/post.md) --- [API](https://skmtc.dev/lance-format/apis/lance-namespace-specification.md) · [All operations](https://skmtc.dev/lance-format/apis/lance-namespace-specification/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/lance-format/lance-namespace-specification/revisions/541331733d0c/schema)