Re: Request: pg_cancel_backend variant that handles 'idle in transaction' sessions

2015-11-05 19:31 GMT+01:00 Joe Conway <mail(at)joeconway(dot)com>:

> On 11/05/2015 10:09 AM, Pavel Stehule wrote:
> > On 5.11.2015 19:02 Merlin Moncure wrote:
> >> Thus, I think we have consensus that transaction_timeout is good -- it
> >> would deprecate statement_timeout essentially. Likewise,
> >> pg_cancel_transaction is good and would deprecate pg_cancel_backend;
> >> it's hard for me to imagine a scenario where a user would call
> >> pg_cancel_backend if pg_cancel_transaction were to be available.
> >
> > I am sorry, I see a consensus between you and Stephen only.
>
> S
> t C
> a<-------------<transaction>--------------->E
> r A B A B A n
> t <idle> <stmt> <idle> <stmt> <idle> d
> |--------======--------======---------------|
>
> Currently we can set timeout and cancel for period B (<stmt>). I can see
> based on this discussion that there are legitimate use cases for wanting
> timeout and cancel for any of the periods A, B, or C.
>
> I guess the question then becomes how we provide that coverage. I think
> for coverage of timeout you need three individual timeout settings.
> However for cancel, it would seem that pg_cancel_transaction would cover
> all three cases.
>

It can be difficult to set it properly, because you don't know how much
statements (cycles of A.B) will be in transaction. Respective for setting
C, I have to know the number of A,B and it isn't possible everytime.

Regards

Pavel

>
> Joe
>
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