CREATE TABLE¶

Lance tables are created through the dynamic table factory (connector = 'lance'). The actual Lance dataset is created lazily on first write.

Minimal example¶

CREATE TABLE vectors (
    id BIGINT,
    content STRING,
    embedding ARRAY<FLOAT>
) WITH (
    'connector' = 'lance',
    'path' = '/data/vectors'
);

With a vector index¶

CREATE TABLE doc_embeddings (
    doc_id BIGINT,
    title STRING,
    embedding ARRAY<FLOAT>
) WITH (
    'connector' = 'lance',
    'path' = '/data/embeddings',
    'index.type' = 'IVF_PQ',
    'index.column' = 'embedding',
    'index.num-partitions' = '256',
    'index.num-sub-vectors' = '16',
    'index.num-bits' = '8',
    'vector.metric' = 'COSINE'
);

Index tuning knobs (all optional, shown with defaults):

The index.* options do not build the index by themselves. They are carried into LanceOptions, and building happens through LanceIndexBuilder, which reads them via LanceIndexBuilder.fromOptions(options):

LanceOptions options = /* same options the table was created with */;
IndexBuildResult result = LanceIndexBuilder.fromOptions(options).buildIndex();

Calling buildIndex() after the data has been written is what materializes the vector index in Lance. Until then, queries fall back to a brute-force scan.

Required options¶

Primary key tables¶

Add PRIMARY KEY ... NOT ENFORCED to switch the table from append-only to upsert:

CREATE TABLE users (
    id BIGINT,
    name STRING,
    embedding ARRAY<FLOAT>,
    PRIMARY KEY (id) NOT ENFORCED
) WITH (
    'connector' = 'lance',
    'path' = '/data/users'
);

Composite primary keys are supported, and the constraint is persisted with the dataset so it survives a catalog round-trip. See INSERT INTO for the changelog modes this enables.

Type mapping¶

See Config for the full option reference.