Re: how to cancel a query in progress

Whit Armstrong <armstrong.whit@gmail.com> writes:
> I had a few queries that were fired from pgAdmin, but failed to stop
> running after I killed the GUI.

> I tried to stop the queries by killing the pid (of the process running
> the query, not the pid of the server) from the linux command line, and
> much to my surprise, the whole database went down and then recovered
> (using the data in pg_xlog I assume).

I suppose you used "kill -9"?  Don't do that.

> So, now that I've learned this lesson, what is the proper way to kill
> a query, and can it be done from psql or are there special postgres
> tools to do this.

kill -INT is a safe query-cancel method.

            regards, tom lane