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Applies to: Embedded ❌, Enterprise ✅ Early access SQL runs in LanceDB Enterprise.

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CREATE FUNCTION

A function takes more than one parameter; each one binds a separate column or literal where the function is called:
Parameter and result types are Arrow type names, not SQL ones: int64, float64, utf8, bool, date32, and lists such as list<float32> or fixed_size_list<float32, 768>. BIGINT is refused. A parameter accepts nulls unless it is declared NOT NULL. The body is Python source. Its dependencies are declared with it and are part of the immutable function version. Changing one produces a new version rather than altering the registered one, so a column filled by an earlier version is unaffected. Errors and limits
Enterprise job type: create_function. Registration returns a job because the function is baked into an image before the version becomes usable.

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Artifact registration

CREATE FUNCTION name FROM '<registration JSON>' accepts the artifact, signature, runtime, optional secret bindings, and result stability produced by the SDK’s registration request. Omit its name property because the SQL identifier supplies it. Escape apostrophes in the JSON as doubled apostrophes. By default, the command waits for its internal image-build job to publish the version, then returns one UTF-8 definition column containing FunctionVersion JSON. WITH (wait = false) instead returns the existing image-build registry job ID in job_id, with operation and status columns. The SDK’s ordinary registration handle has type query and uses the SQL query UUID as its single id; the internal image-build job has type create_function.

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DESCRIBE and ALTER FUNCTION

DESCRIBE returns one definition JSON column for the exact version. include_source defaults to false; source-inclusive reads report an omission when the stored artifact exceeds the inline source limit. ALTER FUNCTION name FROM '<pinned update JSON>' accepts a reference with name, namespace, object ID, location, version, and manifest digest, plus optional metadata and disabled updates. The command checks that reference before appending a revision and returns the resulting definition JSON.

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Call it

Once registered, a function is callable by name in any query, the same as a built-in scalar function:
This is also the fastest way to check a new registration before binding it to a column: call it over a few rows, or over literal arguments, before committing to a computed column that fills from it.

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SHOW FUNCTIONS

SHOW FUNCTIONS returns the highest published numeric revision for each name. Add HISTORY to list every published revision, as Python’s list_functions() does. Rows are ordered by name and numeric revision, so 2 comes before 10. after_name and after_version must be supplied together for keyset pagination. limit bounds the response; include_definition = false omits the optional definition JSON.

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DROP FUNCTION

DROP removes only the requested revision from lookup and listing. Other published revisions and their grants remain available. Dropping the last visible revision releases the name and object binding; physical cleanup continues separately. The result reports dropped or not_found. IF EXISTS allows a missing name or a repeated drop of a previously published revision. A revision that was never published under an existing name is an error. All function object commands retain shared results even when general query-result copying is disabled, so asynchronous polling can resume on another query node.

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What to read next

Function

Registering one from the SDK, and diagnosing environment mismatches.

Computed columns

Filling a column with a function instead of an expression.