Astored procedure is a collection of statements that can be called from otherqueries or other stored procedures. Some stored procedures aresystemprocedures that are built into Spanner. System procedures don't needto be created. Spanner lets you use system procedures.

Because you can't use Spanner to create a stored procedure,Spanner doesn't support stored procedures that aren't built in systemprocedures.

Run a stored system procedure

To run a stored system procedure, you use theCALLstatement:

CALLprocedure_name(parameters);

Replaceprocedure_name with the name of the stored system procedure.You can run one stored system procedure at a time.

Stored system procedures

Spanner supports the following stored system procedure:

• Query cancellation

Query cancellation

This section describes the query cancellation stored system procedure.

Syntax

Thecancel_query stored system procedure cancels a query. You specify thequery to cancel using itsquery_id.

CALLspanner.cancel_query(query_id)

Description

Thecancel_query stored system procedure has the following parameters:

Query cancellations might fail because of one or more of the following:

• The Spanner servers are busy due to heavy query loads.
• The query is in the process of restarting due to an error.

If one of these causes the query to fail, you can run the query cancellationstored system procedure again.