DESCRIBE FUNCTION Enterprise

Returns the metadata about an existing user-defined function (UDF) in the Arctic catalog.

Syntax

{ DESC | DESCRIBE } FUNCTION <function_name>
  [ AT { REF[ERENCE] | BRANCH | TAG | COMMIT } <reference_name> ]
    [ AS OF <timestamp> ]

To run DESCRIBE FUNCTION, users need the USAGE privilege on the Arctic catalog and SELECT privilege on the UDF.

Parameters

<function_name> String

The name of an existing UDF.

---

AT { REF[ERENCE] | BRANCH | TAG | COMMIT } <reference_name> String   Optional

Specifies the reference at which the UDF exists. When this parameter is omitted, the current reference is used.

• REF: Identifies a specific branch, tag, or commit.
• BRANCH: Identifies a specific branch.
• TAG: Identifies a specific tag.
• COMMIT: Identifies a specific commit. Commit hashes must be enclosed in double quotes (for example, “ff2fe50fef5a030c4fc8e61b252bdc33c72e2b6f929d813833d998b8368302e2”.

---

AS OF <timestamp> String   Optional

Changes the commit reference point to the provided timestamp. Can only be applied to REF, BRANCH, and TAG. <timestamp> may be any SQL expression that resolves to a single timestamp type value, for example: CAST( DATE_SUB(CURRENT_DATE,1) AS TIMESTAMP ) or TIMESTAMP '2022-07-01 01:30:00.000'.

Examples

Display the metadata for a scalar function

CREATE FUNCTION hello() RETURNS VARCHAR RETURN 'Hello World!';
DESCRIBE FUNCTION hello
-- Name:        hello
-- Input:       ()
-- Returns:     VARCHAR
-- Owner:       gnarly@example.com
-- Created At:  Wed May 11 17:20:35 EDT 2022
-- Modified At: Wed May 11 17:20:35 EDT 2022
-- Body:        'Hello World!'

Display the metadata for a scalar function

CREATE FUNCTION area (x DOUBLE, y DOUBLE) RETURNS DOUBLE RETURN x * y;
DESCRIBE FUNCTION area
-- Name:        area
-- Type:        SCALAR
-- Input:       x DOUBLE
                y DOUBLE
-- Returns:     DOUBLE
-- Owner:       gnarly@example.com
-- Created At:  Mon Apr 25 19:31:28 EDT 2022
-- Modified At: Mon May 09 09:01:57 EDT 2022
-- Body:        x * y

Display the metadata for a tabular function

CREATE FUNCTION find_fruit (name VARCHAR, color VARCHAR)
    RETURNS TABLE (name VARCHAR, color VARCHAR)
    RETURN SELECT * FROM <catalog-name>.t WHERE <catalog-name>.t.name = find_fruit.name
      AND <catalog-name>.t.color = find_fruit.color;
DESCRIBE FUNCTION find_fruit
-- Name:        find_fruit
-- Input:       "name": "color", "type": "varchar"
-- Returns:     struct<name::varchar>
-- Owner:       gnarly@example.com
-- Created At:  Mon Apr 25 19:31:28 EDT 2022
-- Modified At: Mon May 09 09:01:57 EDT 2022
-- Body:        SELECT "name"\nFROM "<catalog-name>"."t10"\nWHERE ("<catalog-name>"."t"."color" = "color")

Columns

Column	Data Type	Description
Name	varchar	The name of the function.
Input	varchar	The parameters of the function with one tuple per line: parameter_name data_type.
Returns	varchar	The return type of the function. For a scalar function, show <data_type>. For a tabular function, show TABLE ( <column_name> [, ...] ).
Body	varchar	The body of the function, namely, expression or query from the CREATE FUNCTION … RETURN clause.
Created_At	timestamp	The timestamp of when the function was created.
Last_Modified_At	timestamp	The timestamp of when the function was last modified.
Owner	varchar	The current owner of the function.