ALTER TASK

The ALTER TASK statement redefines what a task runs, and nothing else.

It is narrower than CREATE OR REPLACE TASK on purpose: it takes no ON <table_name> clause, so it cannot repoint or create the trigger that fires the task. A schedule trigger's next-due instant is recomputed on every CREATE OR REPLACE TASK, even one that only changes the SQL body — see CREATE TRIGGER ... ON SCHEDULE. A statement that cannot see the trigger at all cannot reset a clock it never touches, which is why this form exists rather than sending every SQL-only edit through CREATE OR REPLACE TASK.

Syntax

sql

ALTER TASK <task_name>
    AS <statement>;

Parameters

<task_name> — the task to redefine, fully qualified as <workspace>.<collection>.<task_name>. Unlike CREATE OR REPLACE TASK, this does not create: a name that is not already a task is refused rather than silently registered.
<statement> — the SQL the task runs from now on. May contain :name placeholders, supplied when the task is executed.

Examples

Redefine a Task's Statement

sql

ALTER TASK my_workspace.ops.ingest_events
    AS INSERT INTO my_workspace.ops.event_log
       SELECT * FROM my_workspace.raw.events VERSION AS OF :current_version;

Notes

Who a task runs as, and whether it runs, still belong to the trigger. Move the owner with ALTER TRIGGER ... OWNER TO, pause it with ALTER TRIGGER ... SUSPEND, or set its firing floor with ALTER TRIGGER ... SET MINIMUM INTERVAL TO. None of those are reachable through ALTER TASK.
Does not reset a schedule trigger's due instant. This is the whole reason the statement exists: redefining a task's SQL body with ALTER TASK leaves any trigger firing it — including its next-due clock — exactly as it was.
The statement is parsed when it is applied, the same as at CREATE TASK, so SQL that could never run is refused now rather than discovered when it fires. What it reads and writes is checked against the author's own grants on every redefinition, the same authoring bound CREATE OR REPLACE TASK applies.
A task cannot create, drop, or run another task.
Relations inside the statement must be fully qualified, the same as at CREATE TASK.