From: mikalaike...@ibagroup.eu [mailto:mikalaike...@ibagroup.eu] > In case of failure PQcancel() terminates in 'socket_timeout'. So, control > to the end-user in such a failure situation will be returned in 2 * > 'socket_timeout' interval. It is much better than hanging forever in some > specific cases. Moreover, such solution will not lead to the overloading > of PostgreSQL server by abnormally ignored 'heavy' queries results by > end-users.
Oops, unfortunately, PQcancel() does not follow any timeout parameters... It uses a blocking socket. Also, I still don't think it's a good idea to request cancellation. socket_timeout should be sufficiently longer than the usually expected query execution duration. And long-running queries should be handled by statement_timeout which indicates the maximum tolerable query execution duration. For example, if the usually expected query execution time is 100 ms, statement_timeout can be set to 3 seconds and socket_timeout to 5 seconds. Regards Takayuki Tsunakawa
