Postgres. Query kill button crashes Heidi.

Heidi issues a KILL statement but there is no KILL in PostgreSQL.
This forum post relates to the issue.
http://stackoverflow.com/questions/11291456/heroku-postgres-terminate-hung-query-idle-in-transaction

Current version 4820

This is rather a nasty issue as it hangs this machine entirely and requires a hard re-boot.
I think the KILL statement takes the Postgres server down altogether.
At present, don't use the kill button to try and terminate a hung query when using PG. Better still make sure your queries are complete before you issue them.
I am something of a novice here and I can only learn from my own mistakes.
Heidi is a great tool and a credit to it's authors.

Is there some similar query in PostgreSQL to cancel a query?

... or to disconnect a session?

Is this of any help here?
http://www.postgresql.org/docs/current/static/functions-admin.html#FUNCTIONS-ADMIN-SIGNAL-TABLE

I'll give it a try.

Try r4823

Thanks Ansgar, that seems to solve the issue.

Please note '<IDLE> in transaction' is/might be a valid state.
It means some transaction has been opened but no query is executed.

It's enough to send BEGIN statement to turn current connection into '<IDLE> in transaction'. In normal conditions, using COMMIT or ROLLBACK should be enough.

but if something went wrong (might be some automated process or so) since there is no query, you cannot cancel query using pg_cancel_backend(pid). You have to use pg_terminate_backend(pid). But it kills connection between client and database.