Stop (long) running SQL query in PostgreSQL when session or requests no longer exist?

Question

I'm not sure where to start on addressing this issue but if I have a AJAX web application that sends requests to the server and runs long queries on the database (postgresql in my case), is there a way to stop or kill the queries if while still running, the user refreshes the page or closes the session...etc?

Answer 1

To stop the query:

SELECT pg_cancel_backend(procpid); 

To kill the database connection:

SELECT pg_terminate_backend(procpid); 

To get an overview of the current transactions, to get the proced id's:

SELECT * FROM pg_stat_activity; 

http://www.postgresql.org/docs/current/interactive/functions-admin.html