To stop vectorize scheduler, refer to pg_stat_activity to check the pid of vectorize scheduler connected to the target database, and then use the pg_ctl kill TERM <pid> command or the SQL function pg_terminate_backend() to stop it. Because vectorize scheduler is continuously connected to the database, if you want to delete or change a database that has CREATE EXTENSIONed pgx_vectorizer, you must stop vectorize scheduler before performing the operation.

You can check the pid of vectorize scheduler connected to the current database by executing the following SQL. The backend_type of vectorize scheduler includes 'vectorize scheduler'.

SELECT pid FROM pg_stat_activity WHERE datid = (SELECT oid FROM pg_database WHERE datname = current_database()) AND backend_type LIKE '%vectorize scheduler%';

Below is an example of using pg_terminate_backend().

rag_database=>SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datid = (SELECT oid FROM pg_database WHERE datname = current_database()) AND backend_type LIKE '%vectorize scheduler%';

 pg_terminate_backend 
----------------------
 t
(1 row)