RE: Timeout parameters

Hello Takayuki-san,

> Yes, so I think it would be necessary to describe how to set
socket_timeout with relation to other timeout parameters -- socket_timeout
> statement_timeout, emphasizing that socket_timeout is not for canceling
long-running queries but for returning control to the client.

For me it does not look enough.
If you would like to implement the 'socket_timeout' parameter, could you
pay attention on the Fabien Coelho comment?

> The fact that no answer data is received may mean that it takes time to
> compute the result, so cancelling seems appropriate to me, rather than
> severing the connection and starting a new one immediately, leaving the
> server loaded with its query.

This comment is very important to pay attention on.
Let's imagine once more:
1. end-user makes a query
2. the query has not completed within this timeout due to any reason: the
query is too 'heavy', some problem with OS happened, PostgreSQL server
terminated
3. if we simple close connection, the first case is negative by mistake.
To avoid such a situation I think it would be better to call a PQcancel().
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.

What do you think about it?

Best regards,
Mikalai Keida