Create features

Persisting features saves their definitions in the registry so they can be referenced, composed, and shared across queries and teams. You create features with CREATE FEATURES and modify metadata with ALTER FEATURE.

Creating a single feature

CREATE [OR REPLACE] FEATURES [IF NOT EXISTS]
  <feature_name> [IN <namespace> [IF EMPTY]]
  AS <SELECT statement>

CREATE TEMPORARY FEATURES
  <feature_name> AS <SELECT statement>

CREATE [OR REPLACE] FEATURES [IF NOT EXISTS]
  <feature_name> [IN <namespace> [IF EMPTY]]
  AS <SELECT statement>

CREATE TEMPORARY FEATURES
  <feature_name> AS <SELECT statement>

The simplest form creates one feature with a fully qualified name:

CREATE OR REPLACE FEATURE FM.TUTORIALS.CAD.FEATURE1 AS 1 + 5;

Use SHOW FEATURES to verify what was created — it displays the feature's name, type, and formula:

SHOW FEATURES (COLUMNS (NAME, DATATYPE, FORMULA)) LIKE 'FM.TUTORIALS.CAD.FEATURE1';

Once persisted, the feature is available in any query:

SELECT FM.TUTORIALS.CAD.FEATURE1;

Creating multiple features

A single CREATE statement can define several features at once. Features can reference each other within the same statement — FeatureQL resolves dependencies automatically regardless of definition order.

CREATE OR REPLACE FEATURES AS
SELECT
    INPUT(BIGINT) AS FM.TUTORIALS.CAD.FEATURE2,
    FM.TUTORIALS.CAD.FEATURE2 + 1 AS FM.TUTORIALS.CAD.FEATURE3,
    CASE WHEN FM.TUTORIALS.CAD.FEATURE3>5 THEN 'BIG' ELSE 'SMALL' END AS FM.TUTORIALS.CAD.FEATURE4,
;

Using CREATE FEATURES IN

Instead of fully qualifying every name, CREATE FEATURES IN sets a target namespace for all features in the statement:

CREATE OR REPLACE FEATURES IN FM.TUTORIALS.CAD AS
SELECT
    5 AS FEATURE5,
;

Replacing features

CREATE OR REPLACE updates an existing feature's definition. FeatureQL validates that the replacement is compatible with any features that depend on it — see Registry consistency for the full set of rules.

CREATE OR REPLACE FEATURES AS
SELECT
    FM.TUTORIALS.CAD.FEATURE3 := FM.TUTORIALS.CAD.FEATURE1 + 10
;

Modifying metadata with ALTER

ALTER FEATURE changes metadata (like descriptions) without touching the feature's computation:

ALTER FEATURE FM.TUTORIALS.CAD.FEATURE5
SET description = 'Feature containing the literal 5';

When to use each variant